Schedule Abstracts Author Index Schedule Saturday Saturday, May 21, 2011, 2:00 PM - 5:00 PM AAVSO Paper Session I Sunday Sunday, May 22, 2011, 9:30 AM - 12:00 PM AAVSO Paper Session II Sunday, May 22, 2011, 1:30 PM - 3:00 PM HAD I: Women in the History of Variable Star Astronomy Sunday, May 22, 2011, 3:20 PM - 5:30 PM HAD II: Variable Star Astronomy in Theory and Practice Monday Monday, May 23, 2011, 8:00 AM - 7:00 PM 125 Stellar Evolution, Stellar Populations AAVSO Poster Session Supernovae. Planetary Nebulae, Evolved Stars, Cataclysmic Variables, Novae Extrasolar Planets: Detection and Characterization Molecular Clouds, HII Regions, Interstellar Medium and Dust Galactic & Extra-Galactic Star Formation Computation, Data Handling, Image Analysis Instrumentation: Ground Based or Airborne Star Clusters and Associations - Galactic & Extra-galactic Laboratory Astrophysics and Catalogs Monday, May 23, 2011, 8:00 AM - 8:30 AM 100 Welcoming Address Monday, May 23, 2011, 8:30 AM - 9:20 AM 101 Kavli Lecture: The 2050 Decadal Survey of Astronomy and Astrophysics Monday, May 23, 2011, 10:00 AM - 11:30 AM 102 12-Years of Science with Chandra: Chandra Observations of the Solar System AAVSO: Astrophysics with Small Telescopes "New Worlds, New Horizons": The Science of Astro2010 Spiral Galaxies, Computation, Data Handling, Image Analysis & Other Topics Black Holes The Galactic Center Monday, May 23, 2011, 11:40 AM - 12:30 PM 109 Stars, Planets and The Weather: If You Don't Like It Wait 5 Billion Years Monday, May 23, 2011, 2:00 PM - 3:30 PM 110 12-Years of Science with Chandra: The X-ray Life of Stars Nuclear Physics I – Stellar Nucleosynthesis Searching for Exoplanets with Kepler Early Science From Pan-STARRS 1 AAVSO: Variable Stars in the Imaging Era Hard X-ray Surveys of AGN Astronomy Unexpected! Innovative Strategies for Reaching Non-Traditional Students Remembering John Huchra Monday, May 23, 2011, 3:40 PM - 4:30 PM 118 Stellar Astrophysics from the Kepler Mission Monday, May 23, 2011, 4:30 PM - 6:00 PM 119 Evolution of Galaxies I Dark Matter & Dark Energy/Large Scale Structures, Cosmic Distance Scale Stars, Dwarfs, Stellar, Circumstellar Disks Binary Stellar Systems, X-ray Binaries Quasars, AGN, Starbursts, and SEDs Tuesday Tuesday, May 24, 2011, 8:00 AM - 7:00 PM 224 The Sun and The Solar System Circumstellar Disks Young Stellar Objects, Very Young Stars, T-Tauri Stars, H-H Objects Results From Kepler 12-Years of Science with Chandra Black Holes Binary Stellar Systems, X-ray Binaries The Milky Way, the Galactic Center Pulsars, Neutron Stars and Related Topics Cosmology Dark Matter & Dark Energy/Large Scale Structures, Cosmic Distance Scale Relativistic Astrophysics, Gravitational Lenses & Waves Galaxy Clusters Gamma Ray Bursts Evolution of Galaxies Tuesday, May 24, 2011, 8:30 AM - 9:20 AM 200 The Pan-STARRS Wide-Field Imaging Survey Tuesday, May 24, 2011, 10:00 AM - 11:30 AM 201 12-Years of Science with Chandra: SNR and Compact Objects Nuclear Physics II – Gamma-Ray Spectroscopy and Radioactive Nuclei Kepler and the Architecture of Planetary Systems SMARTS: Science Results What's New under the Suns? I Cosmic Evolution from Galaxy Zoo Cosmic Microwave Background/ Relativistic Astrophysics, Gravitational Lenses & Waves Tuesday, May 24, 2011, 11:40 AM - 12:30 PM 208 Russell Prize: Mapping the Universe with Redshift Surveys and Weak Lensing Tuesday, May 24, 2011, 2:00 PM - 3:30 PM 209 12-Years of Science with Chandra: Galaxies Nuclear Physics III – Neutrino Astrophysics Exoplanet Characterization with Kepler SMARTS: Current and Future Capabilities What's New under the Suns? II Astronomy Education & Public Outreach Tuesday, May 24, 2011, 3:40 PM - 4:30 PM 216 Early Science with the Expanded Very Large Array Tuesday, May 24, 2011, 4:30 PM - 6:00 PM Star Formation, the Milky Way, Star Clusters Extrasolar Planets: Detection and Characterization Supernovae, PNe, Evolved Stars and other Topics Cosmology Prospects for High Resolution Low Energy X-ray Spectroscopy Tuesday, May 24, 2011, 7:00 PM - 8:00 PM SPD Hale Prize: The Sun's Magnetic Surface Wednesday Wednesday, May 25, 2011, 8:00 AM - 7:00 PM Variable Stars Stellar Atmospheres, Winds SPICA Low-Mass Stellar Science M Dwarfs, Brown Dwarfs, White Dwarfs Blazars, Quasars, and Other AGN Surveys and Large Programs Spiral Galaxies Herschel Instrumentation: Space Missions & Related Topics Intergalactic Medium & QSO Absorption Line Systems Astronomy Education & Public Outreach Dwarf Galaxies Wednesday, May 25, 2011, 8:30 AM - 9:20 AM Demographics in Astronomy and Astrophysics Wednesday, May 25, 2011, 10:00 AM - 11:30 AM 12-Years of Science with Chandra: AGN and SMBHs Particle Physics I – Dense Matter Astrophysics with Kepler I The Panchromatic View of Star Formation and Protoplanetary Disks in Diverse Environments I The Literature-Data Connection: Meaning, Infrastructure and Impact Low-Mass Stellar Science in the Era of Large Surveys Wednesday, May 25, 2011, 11:40 AM - 12:30 PM From Hot Jupiters to Habitable Worlds Wednesday, May 25, 2011, 2:00 PM - 3:30 PM 12-Years of Science with Chandra: Clusters and Groups of Galaxies Particle Physics II – High Energy Astrophysics Astrophysics with Kepler II The Panchromatic View of Star Formation and Protoplanetary Disks in Diverse Environments II The Oort Cloud: How is it Filled? How is it Emptied? SPICA and the Promise of the Far-Infrared Using the Discoveries of Astronomy to Teach Physics Wednesday, May 25, 2011, 3:40 PM - 4:30 PM What Drives the Growth of Black Holes? Wednesday, May 25, 2011, 4:30 PM - 6:00 PM AGN, Mergers, and Jets Dust and Star Formation Galaxy Clusters Pulsars and Neutron Stars Molecular Clouds, HII Regions, Interstellar Medium Thursday Thursday, May 26, 2011, 8:00 AM - 12:00 PM The Sun and Solar System II Extrasolar Planets Stars, Star Formation and Associated Topics Galaxies, Galaxy Clusters and Friends Instrumentation, Surveys and Data High Energy, Cosmology and Other Topics Education Thursday, May 26, 2011, 8:30 AM - 9:20 AM The Least Luminous Galaxies in the Universe Thursday, May 26, 2011, 10:00 AM - 11:30 AM Particle Physics III: Variations of Fundamental Constants and Dark Matter Searches Extrasolar Planets: Theory and Characterization Evolution of Galaxies II Thursday, May 26, 2011, 11:40 AM - 12:30 PM GALEX: Mapping the Hidden Side of Galaxy Evolution and the UV Universe Saturday Abstracts Saturday, May 21, 2011, 2:00 PM - 5:00 PM AAVSO Paper Session I Special Session Harbour/Ipswich, Turner Fisheries Recent Changes in the Orbital Periods of Some Eclipsing SW Sextantis Stars David Boyd1 1BAA, United Kingdom. 2:00 PM - 2:20 PM Harbour/Ipswich, Turner Fisheries We present the results of a project to look for changes in the orbital periods of 18 eclipsing cataclysmic variables known as SW Sextantis stars by combining new measurements of eclipse times with historical data stretching back in some cases over 50 years. While the O-C plots for many of these binary systems are consistent with a constant orbital period, for some there is persuasive evidence that their orbital periods have changed over this time interval. These changes have been investigated and quantified. New ephemerides are provided for all 18 stars to facilitate observation of future eclipses. Secular Variation of the Mode Amplitude-Ratio of the Double-Mode RR Lyrae Star NSVS 5222076, Part 2 David A. Hurdis1, T. Krajci1 1AAVSO. 2:20 PM - 2:40 PM Harbour/Ipswich, Turner Fisheries In 2008, a campaign of time-series observations (Hurdis 2009) was conducted in the V and I bands for NSVS 5222076, a double-mode RR Lyrae (RRd) field star in Bootes. Comparison of those results with the earlier observations of Oaster, Smith, and Kinemuchi (2006) suggested that a rapid and significant decrease might be occurring in the amplitude ratio, A0/A1, of the star‘Äôs fundamental and first-overtone pulsation modes. To follow up on this interesting result, additional campaigns of time-series observations were conducted in 2009, 2010 and 2011. This paper will describe how the amplitude ratio of the star has continued to change. The Pulsational Behaviour of the High Amplitude Delta Scuti Star RS Gruis Jaime Garcia1 1Instituto Copernico, Argentina. 2:40 PM - 3:00 PM Harbour/Ipswich, Turner Fisheries RS Gruis is a high amplitude delta Scuti type variable star with a mean amplitude of almost a half of a magnitude in V, and a period of almost 3.5 hours. The most recent study of this star due to Derekas et al. (2009) suggests the presence of a low-mass dwarf star companion close to the variable star with a period of 11.5 days. Rodriguez et al (1995) had also shown a decreasing rate of the period of dP/Pdt= -10.6 E-8/y. Using a extended dataset comprising BVIc CCD observations aquired at the Astronomical Observatory of the Instituto Cop√©rnico (1000 datapoints), a data set from ASAS (500) and the existing data in the AAVSO International Database (3900), we have performed an extensive periodogram analyses looking for long term variations. As a preliminary result, we have confirmed the period variation rate but we also found an harmonic in good shape with the period suggested for the binary companion. Ha Emission extraction using Narrowband Photometric Filters Gary E. Walker1 1Maria Mitchell Association Observatory. 3:00 PM - 3:20 PM Harbour/Ipswich, Turner Fisheries Maria Mitchell Observatory has explored using Narrowband Photometric (<100A) filters to substitute for spectroscopic observations. The method is thought to have significant signal to noise advantages over spectroscopic observations for small telescopes. These small telescopes offer advantages for projects requiring intensive monitoring where telescope time is limited on larger telescopes. RR Tau, a suspected UXOR, was intensively observed by the MMO 0.6 M RC in Nantucket, Mass and the .29M W28 AAVSOnet telescope from Cloudcroft, New Mexico during the 2010 Winter & Spring season. Observations were made in Ha with 45A and 100A narrowband filters as well as the continuum at 6450 A with 50A and 100A filters. Ha emission was extracted with an error of 8% and compared to the change in the continuum. RR Tau exhibited a 30% change in emission while the continuum change by over a factor of 5. Preliminary Analysis of MOST Observations of the Trapezium Matthew R. Templeton1, J. Guzik2, A. Henden1, W. Herbst3 1AAVSO, 2Los Alamos National Laboratory, 3Wesleyan University. 3:20 PM - 3:40 PM Harbour/Ipswich, Turner Fisheries We present our first assessment of light curves of the Trapezium stars obtained by the MOST satellite in early 2011. The data sets consist of four stars of the Theta 01 Ori system (A,B,C, and D), along with 34 GSC stars in the field nominally used for guiding. The photometry of the brightest stars is sufficient to detect variability at a level well below one mmag, while photometry of the fainter guide stars has not yet been assessed. An early look at the data indicates intrinsic signals are clearly present; non-trivial systematics also related to the spacecraft and sampling are also present, and we discuss potential means for dealing with these issues. We will also discuss our plans for analyzing the data and deriving physical information on these stars. AAVSO Estimates and the Nature of Type C Semiregulars: Progenitors of Type II Supernovae David G. Turner1, K. Moncrieff1, C. Short1, R. Wing2, A. Henden3 1Saint Mary's Univ., Canada, 2Ohio State University, 3AAVSO. 3:40 PM - 4:00 PM Harbour/Ipswich, Turner Fisheries The nature of the variability in the M supergiant type C semiregular (SRC) variables is examined using new and archival spectroscopic and spectrophotometric observations of the stars phased according to AAVSO magnitude estimates. SRC variables appear to be more regular than sometimes suggested, although the nature of their pulsation remains unclear in some cases. Some SRCs appear to undergo irregular fading episodes that may result from dust ejection. But recent light curves of the stars display large scatter that hinders reliable determination of their cycle lengths, a problem that needs to be addressed to improve the usefulness of AAVSO data for learning more about massive stars as they approach the terminal stage of their evolution as Type II supernovae. The Hunt for the Quark-Nova: A Call for Observers David Lane1, R. Ouyed2, D. Leahy2, D. Welch3 1Saint Mary's University, Canada, 2University of Calgary, Canada, 3McMaster University, Canada. 4:00 PM - 4:20 PM Harbour/Ipswich, Turner Fisheries A Quark Nova is the explosive transition from a neutron star to a quark star that is theorized to take place days or weeks after a small fraction of ”normal” Type II supernova events. The Quark Nova signature is the delayed brightening of the new object by about five magnitudes. The proposed close long-term monitoring of Type II supernova events should reveal the presence or absence of the signature double-hump of a Quark Nova and allow us to estimate the frequency or upper limit to the rate of such events. Normal supernova search techniques and follow-up activities may miss the subsequent brightening that takes place during the Quark Nova event. We seek CCD-equipped observers with modest-sized telescopes to join a collaborative effort to search for these events. Your job would begin after Type II supernovae are discovered by others. You, with a team of other observers, would follow all new Type II discoveries for about 1-2 months looking for the signature ”double-bump.” As there are not many known Type II supernovae active at any given time, the observational commitment is not expected to exceed about one-hour per night. We have set up an on-line database to manage the process and record the observations and a communications forum to provide support to the observers and structure to the project (see http://quarknova.ucalgary.ca). The confirmation that these objects exist will be a significant event in supernova research. Sunday Sunday, May 22, 2011, 9:30 AM - 12:00 PM AAVSO Paper Session II Special Session Staffordshire New Life for Old Data: Digitization of Data Published in the Harvard Annals Matthew R. Templeton1, M. Saladyga1, K. Paxson1, R. Stine1, C. Froschlin1, A. Rupp1 1AAVSO. 9:30 AM - 9:50 AM Staffordshire We describe the volunteer-driven project to digitize published visual observations found in the Annals of the Harvard College Observatory, the publication of record for Harvard's variable star data archives prior to the founding of the AAVSO. The addition of published data from the 19th and early 20th centuries to the AAVSO International Database has the potential to enable significant new science by extending long-term light curves farther back in time with high-quality visual and photographic data. AAVSO volunteers working on this project have together digitized over well over ten thousand observations from the Harvard Annals, adding decades to the light curves of some stars. We highlight the work done so far, and show the potential to expand the project by both AAVSO Headquarters and by the volunteers themselves. The Effect of Online Sunspot Data on Visual Solar Observers Kristine Larsen1 1Central Connecticut State University. 9:50 AM - 10:10 AM Staffordshire The Spaceweather website (www.spaceweather.com) hosts a daily picture of the near-side of the sun from SDO/HMI which identifies sunspot groups by number. The site also includes an overall Boulder sunspot number from the past 24 hours. While this information can be helpful for visual sunspot observers who are just beginning to learn the techniques of careful visual sunspot counts (for example, how to identify complex groups and how to carefully examine the limb of the sun), the “power of suggestion” this data might have on an observer cannot be ignored. An observer can check their observation against this “standard” in nearly real-time and may be tempted to alter their data to conform to what they consider to be a more reliable standard. This preliminary study first examined the effects of the Spaceweather site on a class of college students just beginning to learn white light solar observing, and then compared the results of an experienced solar observer with the Spaceweather data. The World Science Festival John Pazmino1 1AAVSO. 10:10 AM - 10:30 AM Staffordshire New York City in the late 20th century rose to be a planetary capital for the sciences, not just astronomy. This growth is mainly in the academic sector but a parallel growth occurred in the public and home field. With the millennium crossing scientists in New York agitated for a celebration of the City as a place for a thriving science culture. In 2008 they began World Science Festival. 2011 is the fourth running, on June 1st-5th, following AAVSO/AAS. World Science Festival was founded by Dr Brian Greene, Columbia University, and is operated thru World Science Foundation. The Festival is 'saturation science' all over Manhattan in a series of lectures, shows, exhibits, performances. It is staged in 'science' venues like colleges and musea, but also in off-science spaces like theaters and galleries. It is a blend of hard science, with lectures like those by us astronomers to science-themed works of art, dance, music. Events are fitted for the public, either for free or a modest fee. While almost all events are on Manhattan, effort is done to geographicly disperse them, even to the outer boros. The grand finale of World Science Festival is a street fair in Washington Square. Science centers in booths, tents, pavilions highlight their work. This fair drew in past years 100,000 to 150,000 visitors. The entire Festival attracts about a quarter million. NYSkies is a proud participant at the Washington Square fair. It interprets the 'Earth to the Universe' display, debuting during IYA-2009. Attendance at 'Earth ...' on just the day of the fair plausibly is half of all visitors in America. The presentation shows the scale and scope of World Science Festival, its relation to the City, and how our astronomers work with it. Variable Star Observing with the Bradford Robotic Telescope Richard C. S. Kinne1 1AAVSO. 10:30 AM - 10:50 AM Staffordshire With the recent addition of Johnson BVRI filters on the Bradford Robotic Telescope's 24 sq. arc minute camera, this scope has become a possibility to be considered when monitoring certain stars such as LPVs. This presentation will examine the mechanics of observing with the BRT and show examples of work that has been done by the author and how that data has been reduced using VPhot. Cosmology with Type Ia Supernovae Kevin Krisciunas1 1Texas A&M University. 10:50 AM - 11:10 AM Staffordshire Phillips (1993) discovered a correlation between the maximum optical brightness of Type Ia supernovae and the rate at which the light curves decline. Within 10 years it was clear that the slope of the decline rate relation was shallower at longer wavelengths. Since 2004 it has been known that in the near-infrared Type Ia supernovae are very nearly standard candles. This makes them particularly useful for determining distances to the host galaxies because a combination of optical and near-IR photometry allows us to determine the extinction by dust even if the dust is very different than normal Milky Way dust. Questions on the grandest scale such as, "What is the ultimate fate of the universe?" hinge on getting accurate distances to objects in the universe. We discuss the advantages of using Type Ia supernovae for cosmology and summarize recent results, such as those of the ESSENCE supernova search, which was carried out with the Cerro Tololo 4-m telescope. Edwin Hubble's Famous Plate of 1923, and a Hubble-Hubble Connection David R. Soderblom1 1STScI. 11:10 AM - 11:30 PM Staffordshire On October 6, 1923 Edwin Hubble used the Mount Wilson 100-inch telescope to take a 45 minute exposure of a field in the Andromeda galaxy. This is the now-famous plate marked with his "VAR!" notation. I will discuss this plate and that notation. I will also tell the story of flying copies of that plate on the deployment mission for HST in 1990 as a Hubble memento and then locating those copies afterwards, and how copies were flown on Servicing Mission 4 on 2009 as well. This has led to an effort in which AAVSO members joined to identify and reobserve that noted star, arguably the most important object in the history of cosmology, but largely ignored since Hubble's time. Sunday, May 22, 2011, 1:30 PM - 3:00 PM HAD I: Women in the History of Variable Star Astronomy Special Session Staffordshire The Legacy of Annie Jump Cannon: Discoveries and Catalogs of Variable Stars. Barbara L. Welther1 1Smithsonian. 1:35 PM - 1:55 PM Staffordshire This paper will review the many variable-star projects and publications that Cannon brought to fruition in her 45-year career at Harvard College Observatory. In 1896, when Cannon joined the "Corps of Women Computers" at HCO, Williamina Fleming already enjoyed world-wide acclaim for her discoveries of novae on photographs of stellar spectra. Antonia Maury had also become renowned: she had discovered and analyzed a rare spectroscopic binary star, Beta Aurigae. At that time, such discoveries made headlines in newspapers, especially because they were made by women who studied astronomy by day! When Cannon was not actively involved in classifying stellar spectra, she took up HCO's project of cataloging observations of variables. As a result, she discovered thousands of long-period variable stars and half a dozen novae in the Milky Way. In 1903 she published "A Provisional Catalogue of Variable Stars" in Harvard Annals 48. Subsequently, Margaret Walton Mayall and Florence Campbell Bibber continued cataloging the variables through 1941, when Cannon died. In 1918, when Cannon and others such as Edward Pickering and Solon Bailey, were made honorary members of the American Association of Variable Star Observers, Cannon wrote: "I assure you it is a pleasure to be associated in this way, with a company of ardent observers and investigators, whose results are of so much value and carried on with such enthusiasm. It well be a spur to me in my future work, especially as to the new Catalogue of Variable Stars, which I hope to finish before very long." Anne S. Young: Professor and Variable Star Observer Extraordinaire Katherine Bracher1 1Whitman College. 1:55 PM - 2:10 PM Staffordshire Anne Sewell Young (1871-1961) was one of the eight original members of the AAVSO, to which she contributed more than 6500 observations over 33 years. She also taught astronomy for 37 years at Mount Holyoke College; among her students was Helen Sawyer Hogg. This paper will look at her life and career both at Mount Holyoke and with the AAVSO. The Stars Belong to Everyone: Astronomer and Science Writer Dr. Helen Sawyer Hogg (1905-1993) Maria J. Cahill1 1Edison State College. 2:10 PM - 2:40 PM Staffordshire University of Toronto astronomer and science writer Helen Sawyer Hogg (President of the AAVSO 1939-41) served her field through research, teaching, and administrative leadership. Additionally, she reached out to students and the public through her Toronto Star newspaper column entitled “With the Stars” for thirty years; she wrote The Stars Belong to Everyone, a book that speaks to a lay audience; she hosted a successful television series entitled Ideas; and she delivered numerous speeches at scientific conferences, professional women’s associations, school programs, libraries, and other venues. This paper will illumine her life and the personal and professional forces that influenced her work. Variable Stars and Constant Commitments: The Stellar Career of Dorrit Hoffleit Kristine Larsen1 1Central Connecticut State University. 2:40 PM - 3:00 PM Staffordshire Astronomer, educator, and science historian Dorrit Hoffleit (1907-2007) was widely respected by the amateur and professional astronomical community as a mentor and an ardent supporter of independent research. Her more than 600 catalogues, books, articles, book reviews, and news columns cover myriad aspects of astronomy, from variable stars and stellar properties to meteor showers, quasars, and rocketry. She also made important contributions to the history of astronomy. Hoffleit worked at the Harvard College Observatory from 1927-1956, where she discovered over 1200 variable stars. When Director Harlow Shapley retired from Harvard, Hoffleit gave up her tenured position and moved to Yale University, where she was placed in charge of the Yale Catalog of Bright Stars. At the same time, she was offered a position as director of the Maria Mitchell Observatory on Nantucket Island in Massachusetts. Hoffleit split her dual positions into six-month stints and remained director at the Mitchell Observatory for 21 years, developing a summer research program that engaged more than 100 undergraduate students (all but three of them women) in variable star research. Up until shortly before her death, she continued to work tirelessly on selected projects, and she was in high demand as a collaborator with colleagues at Yale and elsewhere. She was especially devoted to the American Association of Variable Star Observers (AAVSO) in part because it brought together amateur and professional astronomers in collaboration. She served on the organization’s council for 23 years and as its president from 1961-1963. In 2002, the AAVS0 published her autobiography, Misfortunes as Blessings in Disguise, in which Hoffleit explains how she always felt blessed by the opportunities in her life, even those which initially seemed misfortunes, and above all else valued creativity, flexibility, collegiality, and intellectual freedom in her professional life. Sunday, May 22, 2011, 3:20 PM - 5:30 PM HAD II: Variable Star Astronomy in Theory and Practice Special Session Staffordshire King Charles` Star: A Multidisciplinary Approach to Dating the Supernova Known as Cassiopeia A Martin Lunn1 1Yorkshire Museum, United Kingdom. 3:25 PM - 3:40 PM Staffordshire Few astronomical phenomena have been as studied as the supernova known as Cassiopeia A. Widely believed to have occurred in the latter half of the seventeenth century, it is also thought to have gone unrecorded. This paper will argue that Cas A did not go unobserved, but in fact was seen in Britain on May 29, 1630, and coincided with the birth of the future King Charles II of Great Britain. This ‘noon-day star’ is an important feature of Stuart/Restoration propaganda, the significance of which has been widely acknowledged by historians and literary experts. The argument here, however, is that in addition the historical accounts provide credible evidence for a genuine astronomical event, the nature of which must be explained. Combining documentary analysis with an overview of the current scientific thinking on dating supernova, the authors put forward their case for why Charles’ star should be recognized as a sighting of Cas A. Finally, it will be argued that a collaborative approach between the humanities and the sciences can be a valuable tool, not just in furthering our understanding of Cas A, but in the dating of supernovae in general. John Goodricke, Edward Pigott, and Their Study of Variable Stars Linda M. French1 1Illinois Wesleyan Univ.. 3:40 PM - 4:00 PM Staffordshire John Goodricke (1764-1786) and Edward Pigott (1753-1825) are credited with determining the first accurate periods for several important variable stars. Goodricke's name is associated with the determination of the period of the eclipsing binary Algol (Beta Persei); for this he was awarded the Copley Prize of the Royal Society of London. He also determined the periods of the contact binary Beta Lyrae and of Delta Cephei, the prototype Cepheid variable. Around the same time, Edward Pigott obtained the period of Eta Aquilae, another Cepheid. In actuality, the two collaborated on all these observations; today we would call them co-discoverers. Goodricke is the better known of the two, in part because he won the Copley Medal, in part because of his tragically short life, and in part because he was deaf. Edward Pigott was the more experienced observer, having worked with his father Nathaniel on determining the longitudes of several cities on the Continent. Evidence shows, however, that Goodricke had some astronomical experience while a student at the Warrington Academy. The journals of the two show that they developed a partnership that made the most of both their talents over the brief time (less than five years) they worked together before Goodricke's death. Today, the two are remembered as having suggested eclipses as the cause for the periodic dimming of Algol. This explanation is accepted today as the correct one. In their day, however, most eminent astronomers believed that starspots were a more likely cause for the dimming. By the time of John Goodricke's death, he seems to have accepted that explanation as well. A study of the work of Goodricke and Pigott contains many lessons for today's observers of variable stars. This work was supported by an AAS Small Research Grant and by the Pollack Award of the Dudley Observatory. The development of early pulsation theory, or, how Cepheids are like steam engines" Matthew Stanley1 1New York University. 4:00 PM - 4:25 PM Staffordshire The pulsation theory of Cepheid variable stars was a major breakthrough of early twentieth-century astrophysics. At the beginning of that century, the basic physics of normal stars was very poorly understood, and variable stars were even more mysterious. Breaking with accepted explanations in terms of eclipsing binaries, Harlow Shapley and A.S. Eddington pioneered novel theories that considered Cepheids as pulsating spheres of gas. These theoretical models relied on highly speculative physics, but nonetheless returned very impressive results despite attacks from figures such as James Jeans. Surprisingly, the pulsation theory not only depended on developments in stellar physics, but also drove many of those developments. In particular, models of stars in radiative balance and theories of stellar energy were heavily inspired and shaped by ideas about variable stars. Further, the success of the pulsation theory helped justify the new approaches to astrophysics being developed before World War II. Frank Elmore Ross and his Variable Star Discoveries Wayne Osborn1 1Yerkes Observatory/Central Mich. U. 4:30 PM - 4:45 PM Staffordshire Frank Elmore Ross (1874-1960) was a talented astronomer that excelled in such diverse fields as computational astronomy, optical instrument design and astrophotography. Today he is remembered in astronomy mainly for his lists of stars of high proper motion, many of which are among our closest neighbors. A by-product of his searches for high proper motion stars was the discovery of 379 new variable stars. The identities of a number of these “Ross variables” are still uncertain and the variability yet to be confirmed more than eighty years after publication, largely due to imprecise or erroneous coordinates. Ross’s original observing cards and plates have been located and are being used to re-examine the stars. The cases of uncertain identity or variability are being resolved, and better magnitudes are being determined for these early-epoch observations. Many of the Ross variables are poorly studied and follow-up observations of a few of these stars have yielded some interesting results. Stellar Pulsation Theory from Arthur Stanley Eddington to Today Steven D. Kawaler1, C. J. Hansen2 1Iowa State Univ., 2University of Colorado. 4:45 PM - 5:05 PM Staffordshire While one could question that Eddington was the pioneer in theoretical work directly addressing the pulsating variable stars, there is no doubt that his work in the first part of the 20th Century set the stage for a transformation of theoretical astrophysics. After Eddington (the 1940s to the present day) stellar pulsation theory evolved from analytic theory into the realm of computational physics. Starting from Eddington's formulation, the flexibility provided by numerical solutions enabled exploration of systematics of pulsating variable stars in vastly greater detail. In this talk, we will trace this development that led to theoretical explanations of period-luminosity relations, new mechanisms of pulsation driving, connections with mass loss and stellar hydrodyamics, and to modern asteroseismic probes of the Sun and the stars. The AAVSO Photoelectric Photometry Program in its Scientific and Socio-Historic Context John R. Percy1 1Univ. of Toronto, Canada. 5:05 PM - 5:30 PM Staffordshire Photoelectric photometry began in the 1900s through the work of Guthnick, Stebbins, and others who constructed and used photometers based on the recently-discovered photoelectric effect. The mid 20th century saw a confluence of several areas of amateur interest: astronomy, telescope making, radio and electronics, and general interest in space. This is the time when AAVSO photoelectric photometry (PEP) began, with observers using mostly hand-built photometers on hand-built telescopes. The 1980s brought a revolution: affordable off-the-shelf solid-state photometers, and infrastructure such as the International Amateur-Professional Photoelectric Photometry (IAPPP) conferences, books, and journal. The AAVSO developed a formal PEP program in the early 1980s. Its emphasis was on long-term monitoring of pulsating red giants. It was competing, not always successfully, with programs such as active sun-like binaries (RS CVn stars) which offered "instant gratification" in the form of publicity and quick publications. Nevertheless, the AAVSO PEP program has, through careful organization, motivation, and feedback to observers, produced extensive scientific results. In this presentation, I shall describe, as examples, my own work, its scientific significance, its educational benefit to dozens of my students, and its satisfaction to the observers. To some extent, the AAVSO PEP program has been superceded by its CCD program, but there is still a useful place for ongoing PEP observations of thousands of variable stars. Reference: http://www.aavso.org/sites/default/files/newsletter/PEP/lastpepnl.pdf Acknowledgements: I thank NSERC Canada for research support, my students, and AAVSO staff and observers, especially Howard Landis. Monday Monday, May 23, 2011, 8:00 AM - 7:00 PM 125 Stellar Evolution, Stellar Populations Poster Session Essex Ballroom 125.01 Using High Precision Stellar Observations to Constrain the Physics of Convection in Stars Timothy Carleton1, C. Meakin1 1Steward Observatory. 8:00 AM - 7:00 PM Essex Ballroom Arguably the most significant barrier to our full comprehension of stellar structure and evolution is the uncertainty in our understanding of stellar convection and its attendant mixing. Our current understanding of stellar convection, mixing length theory (MLT), describes convection as a process in which warmer pockets of fluid flow to the surface through a temperature gradient. The efficiency at which this transfers heat is dependent on the ratio of the surface area to the volume of the globule, gml. We use the stellar evolution simulation package MESA (Modules for Experiments in Stellar Astrophysics) together with new high precision observations of non-interacting binaries to constrain convection physics in low mass stars (M<1.2 Msun), specifically gml. Our data set contains 45 stars with precision mass, temperature and luminosity measurements (uncertainties at the few percent level) as well as observed relationships between turbulent surface velocity, surface gravity, and luminosity. This research was supported by the Arizona Space Grant Consortium. 125.02 The Physics of AGB Mass Loss Lee Anne M. Willson1, Q. Wang1 1Iowa State Univ.. 8:00 AM - 7:00 PM Essex Ballroom To investigate the importance of physical processes in the stellar atmosphere on the mass loss rates of AGB stars, we have run a substantial grid of dynamical atmosphere models using a code that approximates non-LTE, dust formation, and radiative transfer via one or two parameters each, and using R(L, M, Z, l/H) to investigate the importance of low gravity and metallicity. This gives us six parameters to investigate: Criticial density (for the onset of non-LTE), opacity kappa (determines the photospheric density), Tcondensation and ΔTcondensation (for dust formation), mixing length parameter l/H, and Z, M (for the initial stellar model). We find the location of the Deathline, where dlnM/dt = dlnL/dt, is quite stable, shifting by ΔlogLdeath < ~0.1 with variation of any of the parameters inside reasonable limits. We find that the biggest uncertainty in the model-based Deathline is introduced by the uncertainty in R(L, M, Z) represented by varying l/H in the models. The condensation of dust and the non-LTE transfer both have a great effect on the structure of the atmosphere, and affect the outflow velocity in the wind, but neither of these makes a large difference in the predicted Deathline. Observational constraints on the Deathline include the Mira P-L relation and a variety of published empirical mass loss formulae. Research supported by NSF AST0708143. 125.03 The Wfpc2 Uv Survey Of Globular Clusters: The Case Of Ngc 6229 Nicoletta Sanna1, R. T. Rood1, G. Beccari2, E. Dalessandro3, F. R. Ferraro3, B. Lanzoni3 1University of Virginia, 2European Southern Observatory, Germany, 3University of Bologna, Italy. 8:00 AM - 7:00 PM Essex Ballroom One of the valedictory projects undertaken by WFPC2 was a survey of UV bright objects in 30 globular clusters. Eventually these results will be combined with similar results obtained by our group for 15 clusters. For most of these clusters observations were obtained with 4 or more filters. For a subset of clusters we also have observations from GALEX which will allow us see if the sort radial variations previously found in blue straggler stars (BSS) also exists in the hottest stellar populations. Here we present the case of NGC 6229. The data set has been obtained by combining high-resolution (HST/WFPC2 and ACS) and wide-field space (GALEX) observations and ground-based (MegaCam-CFHT) images. The photometric sample covers the entire cluster extension from the very central regions up to the tidal radius and beyond. We determine the radial density profile and we study the BSS population and its radial distribution. 125.04 IRAS 20050+2720: Time Scales Of Pre-main Sequence Evolution Hans Moritz Guenther1, S. J. Wolk1, B. Spitzbart1, R. A. Gutermuth2 1SAO, 2Smith College/UMass. 8:00 AM - 7:00 PM Essex Ballroom We present results of our multiwavelength study of IRAS 20050+2720, a young stellar cluster, which is thought to be located at 700 pc. IRAS 20050+2720 displays an exceptionally low 24 micron background, because no massive stars are present. We concentrate on Chandra and Spitzer data and compare cluster properties of an IR sample (as previously presented by Guthermuth et al. 2009) and an X-ray selected sample. Compared to previous works the IR coverage has been extended with new observations. Foreground X-ray sources are separated with optical photometry and we treat the remaining disk-less sources as the class III population of the cluster. It turns out, that the class III sources are much less clustered than class I and II sources. The low 24 micron background allows us to achieve a more complete sample at this wavelength than in other star forming regions. Therefore, our census of transition disk objects between class II and class III should be more complete. We use this to put limits on the time scale of disk dispersal. This work has been funded by Chandra award GO6-7017X. 125.05 Multi-wavelength Analysis of Young Stellar Objects in the W4 Star Forming Region Micaela B. Bagley1, J. S. Kim1, W. H. Sherry2, M. R. Meyer3, M. M. Bagley1 1University of Arizona, 2NOAO/NSO, 3ETH Zurich, Switzerland. 8:00 AM – 7:00 PM Essex Ballroom We present our preliminary results of an optical survey of the W4 star forming region. W4 is an H II region located at a distance of about 2 kpc. Its central young star-forming cluster, IC 1805, contains well-studied massive stars making this an ideal region for studying the relationship between high- and low-mass star formation. As part of the W3/W4/W5 star-forming complex, stellar populations in the W4 region provide an opportunity to study the possibility of triggered star formation. We have performed an optical imaging survey of these regions using the 90Prime imager at the Bok telescope. Our preliminary results focus on intermediate to low-mass populations of W4. This work is part of a larger project to study the star-formation history, initial mass function, and circumstellar disk evolution of the W3/W4/W5 complex. Our observations are sensitive down to about 0.5 solar masses. We select candidate pre-main sequence stars based on their location in V-I, V color-magnitude diagrams compared to model isochrones. Preliminary tests have found about 1500 candidate stars with initial age estimates less than 3 Myr. We use infra-red data from the 2MASS catalog and the Spitzer Space Telescope to estimate the circumstellar disk frequency as a function of age and mass in this region. X-ray data from the Chandra X-ray Observatory also help select candidate young stars. These candidates will be targeted for optical spectroscopy to better determine stellar masses and ages. Here we present the spatial distribution of both confirmed and candidate young stars in the W4 star-forming region. 125.06 The Red and Yellow Supergiants in M33: Kinematics and Massive Star Evolution Philip Massey1, M. Drout2, S. Tokarz3, N. Caldwell3 1Lowell Obs., 2University of Cambridge, United Kingdom, 3Smithsonian Astrophysical Observatory. 8:00 AM – 7:00 PM Essex Ballroom Massive star evolution is hard to model, owing to the complications of mass-loss, uncertainties over mixing and convection, the effects of rotation, and so on. It is generally agreed that the most massive stars spend their He-burning lives as Wolf-Rayet stars. Stars of slightly smaller masses spend most of their He-burning phase as red supergiants, after briefly passing through a yellow supergiant phase. We are interested in identifying the numbers and physical properties of these stars throughout the star-forming galaxies of the Local Group in an effort to test stellar evolutionary models at varying metallicities. However, foreground contamination by Milky Way dwarfs is severe for both the yellow supergiants (YSGs) and red supergiants (RSGs). Using the photometry of the Local Group Galaxy Survey, we have used two-color information (B-V vs V-R) to separate likely foreground dwarfs from bona fide RSGs in M33, and obtained radial velocities with Hectospec on the 6.5-m MMT. The radial velocities refine the rotation curves of previous studies, and demonstrate that the rotation curve is quite flat. With the new velocity data we then separate the yellow supergiant population from the foreground using radial velocities as well. Since the number of Wolf-Rayet stars is now known to a few percent in M33 (Neugent et al. 2011, ApJ, in press, as well as poster at this meeting) it is now possible to compare the numbers of RSGs, YSGs, and WRs in this nearby spiral. This work is supported by the National Science Foundation through AST-1008020. 125.07 Wolf-Rayet Stars in the Local Group Kathryn Neugent1, P. Massey1 1Lowell Observatory. 8:00 AM – 7:00 PM Essex Ballroom The physics behind hot, massive stars is complicated, making the stars’ properties difficult to model. For this reason, we rely on observational tests to see how well stellar evolutionary theory predicts the relative numbers of various types of massive stars. The star-forming galaxies of the Local Group, with their varying metallicities, provide an excellent laboratory for such studies, as massive star evolution is strongly influenced by mass-loss rates, which in turn depend upon metallicity, at least on the main sequence. We’ve recently begun a far deeper, and more complete survey of the Wolf-Rayet (WR) content of Local Group galaxies compared to what has been done in the past. Here we discuss our candidate selection process, as well as the results from our most recent study of M33 which yielded 56 new WR stars. The relative number of WCs to WNs would support there being a strong metallicity gradient. This work was supported by the National Science Foundation under AST-1008020. 126 AAVSO Poster Session Poster Session Essex Ballroom 126.01 Data Release 3 of the AAVSO All-Sky Photometric Survey (APASS) Arne A. Henden1, S. E. Levine2, D. Terrell3, T. C. Smith4, D. L. Welch5 1AAVSO, 2Lowell, 3SwRI, 4Dark Ridge Observatory, 5McMaster University, Canada. 8:00 AM - 7:00 PM Essex Ballroom APASS is an all-sky survey in 5 filters (B,V,g',r',i') covering the magnitude range 10<V<17. It is currently underway at two sites: Dark Ridge Observatory in New Mexico, and CTIO in Chile. The survey will take approximately two years to complete, and will provide a precision of 0.02mag for well-sampled stars. This paper presents the current status of the project and provides the access methods to the catalog. 126.02 AAVSOnet: The Robotic Telescope Network Mike Simonsen1 1AAVSO. 8:00 AM - 7:00 PM Essex Ballroom AAVSOnet is the growing network of robotic telescopes owned and operated by the American Association of Variable Star Observers. With telescopes ranging from 60mm to .61m in aperture located around the globe, the network fulfills a multitude of science goals. The largest telescopes will be fitted with instruments capable of doing both spectroscopy and photometry. We have pairs of 20cm telescopes in Chile and New Mexico conducting an all-sky photometric survey from 10th to 17th magnitude. These pairs of telescopes monitor the sky in two filters simultaneously in Johnson B and V, as well as Sloan g, r, i, and z. There are telescopes in the 25-35cm range available to conduct automated programs of stars selected by AAVSO members, and five small telescopes monitoring poorly studied stars brighter than 10th magnitude in both the southern and northern hemispheres. All the data for every star on every image is archived at AAVSO headquarters for future data-mining and images are uploaded to member accounts where they can be analyzed by a powerful suite of photometric tools and observations submitted to the AAVSO International Database. 126.03 High Speed UBV Photometry Of Epsilon Aurigae's 2009-2011 Eclipse Aaron Price1, G. Billings2, B. Gary2, B. Kloppenborg3, A. Henden2 1AAVSO/Tufts University, 2AAVSO, 3Denver University. 8:00 AM - 7:00 PM Essex Ballroom We present rapid cadence U, B and V photometry of epsilon Aurigae during its 2009-2011 eclipse. Data is analyzed to look for both periodic and random variation. Observations are presented from two observers. The first is from Rockyford, Alberta, Canada and used a ST-7 and ST-8XME with 50mm and 135mm lenses, respectively. This observer recorded continuous filtered time series up to 11 hours long. The second is in Hereford, AZ and used a ST-10XME with a .36m SCT. 126.04 20 Million Observations: the AAVSO International Database and its First Century Elizabeth O. Waagen1 1AAVSO. 8:00 AM - 7:00 PM Essex Ballroom The American Association of Variable Star Observers (AAVSO) turns 100 in 2011 - a century of service to the astronomical community! Another milestone was reached in 2011: the AAVSO International Database (AID) received its 20 millionth variable star observation! The AID contains observations of over 14,750 objects contributed by over 7,500 amateur and professional astronomers worldwide. Data on hundreds of objects extend from the AAVSO’s founding in 1911 or earlier (mid-1800’s) to present. Some objects’ data are of shorter duration but of intense, high-precision coverage. Historical datasets come from published/unpublished professional/amateur observations, astronomical plate collections, and contributed archives of other variable star observing organizations. Hundreds of observations are added to the AID daily as observers upload their data in near real-time. Approximately 69% (~13.9M) of AID observations are visual, 30.4% (~6.2M) CCD (BVRI, unfiltered, Sloan colors, others), 0.5% (~75K) PEP (BVJH), and 0.1% (~17K) photographic/photovisual. Many objects have exclusively visual data, some PEP or CCD data only, and many a combination of types and bands. Objects range from young stellar objects through highly evolved stars. Included are intrinsic variables - pulsating (SX Phe stars through Miras and semiregulars) and eruptive (cataclysmic variables of all types) - and extrinsic variables - eclipsing binaries, rotating (RS CVns) - and exoplanets and suspected variables. Blazars, polars, quasars, HMXBs - today’s AID is a thriving, exciting resource! The AID is maintained in a dynamic MySQL database, easily accessible to contributors and users alike through the AAVSO website (http://www.aavso.org). The Light Curve Generator, Quick Look page (recent observations), and Data Download form offer different ways to view/investigate your targets. Quality control performed from submission through validation ensures reliable data for your research. Visit the AAVSO website if you need data; contact us if we may help you observe your targets. We are here for you! 126.05 Professional Astronomers in Service to the AAVSO Michael Saladyga1, E. O. Waagen1 1AAVSO. 8:00 AM - 7:00 PM Essex Ballroom Throughout its 100-year history, the American Association of Variable Star Observers (AAVSO) has welcomed professional astronomers to its membership ranks, and has encouraged their participation as organization leaders. The AAVSO has been fortunate to have many distinguished professionals serve as officers (Directors, Presidents, Council), and as participants in its various scientific and organizational committees. 126.06 The Citizen Sky Planetarium Trailer Rebecca Turner1, A. Price1, R. Wyatt2 1AAVSO, 2California Academy of Sciences. 8:00 AM - 7:00 PM Essex Ballroom Citizen Sky is a multi-year, citizen science project focusing on the bright variable star, epsilon Aurigae. We have developed a six-minute video presentation describing eclipsing binary stars, light curves, and the Citizen Sky project. Designed like a short movie trailer, the video can be shown at planetariums before their regular, feature shows or integrated into a longer presentation. The trailer is available in a wide range of formats for viewing on laptops all the way up to state-of-the-art planetariums. The show is narrated by Timothy Ferris and was produced by the Morrison Planetarium and Visualization Studio at the California Academy of Sciences. This project has been made possible by the National Science Foundation. 126.07 Status of the USNO Infrared Astrometry Program Frederick John Vrba1, J. A. Munn1, C. B. Luginbuhl1, T. M. Tilleman1, A. A. Henden2, H. H. Guetter1 1U.S. Naval Obs., 2AAVSO. 8:00 AM - 7:00 PM Essex Ballroom The USNO Infrared astrometry program has been in a suspended state since a June 2006 cryogenic accident with our imaging camera. We describe the current status of bringing the program back to full operation. We expect to re-start an expanded astrometric program in the near future and present our initial list of targets. This will also provide an opportunity for the community to suggest potential cool, low-mass targets which are in need of high quality parallaxes and proper motions. We earlier published preliminary astrometric results for 40 L and T dwarf fields based on the first two years of observations [Vrba et al., AJ, 127, 2948 (2004)]. Those initial objects plus an additional 19 fields added later comprise a total of one M dwarf, 28 L dwarfs, and 39 T dwarfs, including objects in binary systems. Final parallaxes and proper motions for these objects will be published later this year. The additional approximately four years of observations for the original 40 objects improve the mean parallax errors orginially reported from 4.31 mas to 1.73 mas, with the best at 0.64 mas, and the mean proper motion errors from 6.56 mas/yr to 1.09 mas/yr. 126.08 Membership of the Planetary Nebula Abell 8 in the Open Cluster Bica 6 and Implications for the PN Distance Scale David G. Turner1, J. M. Rosvick2, D. D. Balam3, A. A. Henden4, D. J. Majaess1, D. J. Lane1 1Saint Mary's Univ., Canada, 2Thompson Rivers University, Canada, 3Dominion Astrophysical Observatory, Canada, 4AAVSO. 8:00 AM - 7:00 PM Essex Ballroom The potential link between the newly discovered open cluster Bica 6 and the planetary nebula (PN) Abell 8 (PN G167.0−00.9) proposed by Bonnato et al. (2008) is confirmed on the basis of new UBVRI CCD photometry for the cluster and spectroscopic observations of its brightest stars, in conjunction with an analysis of 2MASS data for the cluster. The reddening, estimated distance, and radial velocity (+58 ± 6 km/s) of Abell 8 are a close match to the parameters derived for Bica 6: E(B−V)(B0) ≈ 0.40, d = 1.6 kpc, Vr = +57 ±4 km/s (11 stars). The radial velocity match is particularly interesting given that the velocities are more than 50 km/s larger than expected for Galactic orbital motion at l = 167°. The cluster age of 1 billion years implies a mass of ∼2.5-3 M⊙ for the planetary nebula progenitor star, although the picture is complicated by a few blue stragglers as likely cluster members. The central star of the PN is an optical double in the 2MASS survey, with the companion indicated to be a cluster M dwarf. Abell 8 is a highly evolved PN containing a low luminosity central star (Mv ≈ +8), with a distance implied by cluster membership favoring the short PN distance scale. 126.09 Amateur Observing Patterns and Their Potential Impact on Variable Star Science Matthew R. Templeton1 1AAVSO. 8:00 AM - 7:00 PM Essex Ballroom In this poster I highlight some trends seen in amateur observations submitted to the AAVSO over the past 50 years. Some systematic trends are noted in both the amount of data submitted and the frequency with which stars are observed. Two trends are particularly notable: the decreasing number of days per year when individual stars are observed, and the overal decreasing number of visual observations submitted. The former is shown through an analysis of data submitted for a number of subclasses of cataclysmic variable, while the latter is generally evident across all variable star types through our overall annual totals. A decrease in nightly coverage may impact the kinds of science that can be done with AAVSO light curves, particularly for dwarf novae that can change on a nightly basis. The decrease in visual observing may result in either a loss of long-term coverage which impacts the usability of log-term light curves, or in a change from visual to instrumental coverage which can impact the statistical properties of the data making it more challenging to extract physical information. I discuss possible impacts on the kinds of science that can be done with AAVSO data and long-term light curves generally, & suggest ways to address this issue. 126.10 An Overview of the Evolution of the AAVSO's Information Technology Infrastructure Between 1965-1997 Richard C. S. Kinne1, M. Saladyga1, E. O. Waagen1 1AAVSO. 8:00 AM - 7:00 PM Essex Ballroom We trace the history and usage of computers and data processing equipment at the AAVSO HQ between its beginings in the 1960s to 1997. We focus on equipment, people, and the purpose such computational power was put to use. We examine how the AAVSO evolved its use of computing and data processing resources as the technology evolved in order to further its mission. 126.11 Rasch Analysis of Scientific Literacy in an Astronomical Citizen Science Project Aaron Price1 1AAVSO/Tufts University. 8:00 AM - 7:00 PM Essex Ballroom We investigate change in attitudes towards science and belief in the nature of science by participants in a citizen science project about astronomy. A pre-test was given to 1,385 participants and a post-test was given six months later to 165 participants. Nine participants were interviewed. Responses were analyzed using the Rasch Rating Scale Model to place Likert data on an interval scale allowing for more sensitive parametric analysis. Results show that overall attitudes did not change, p = .225. However, there was significant change towards attitudes relating to science news (positive) and scientific self efficacy (negative), p < .001 and p = .035 respectively. This change was related to social activity in the project. Beliefs in the nature of science exhibited a small, but significant increase, p = .04. Relative positioning of scores on the belief items suggests the increase is mostly due to reinforcement of current beliefs. 126.12 Collaborative Research Efforts For Citizen Scientists Brian K. Kloppenborg1, A. Price2, R. Turner2, A. Henden2, R. Stencel1 1University of Denver, 2AAVSO. 8:00 AM - 7:00 PM Essex Ballroom The AAVSO's Citizen Sky project encourages participants not just to collect and categorize data, but instead to critically analyze and publish research findings. Our participants form teams of different, yet complementary skills that work together towards a common goal. Each team has a leader and a professional astronomer assigned to act as an advisor. In this work we explore the formation of teams, by what means they find research topics, and how they manage their collaborations. We acknowledge support from the NSF Informal Science Education Division under grant DRL-0840188, to the AAVSO and the University of Denver. 127 Supernovae. Planetary Nebulae, Evolved Stars, Cataclysmic Variables, Novae Poster Session Essex Ballroom 127.01 Strengthening the Connection Between Space and Society: A Comparative Analysis of Supernovae Distribution in the Andromeda Galaxy for Secondary School Students Kareen Borders1, B. Mendez2, K. Borders3, M. Thaller4, M. Plecki1, K. Usuda5 1University of Washington, 2University of California at Berkeley, 3Peninsula High School, 4NASA, 5Subaru Telescope. 8:00 AM - 7:00 PM Essex Ballroom In order to prepare students in grades 4-12 for a global workforce, NASA supports science, technology, engineering, and math (STEM) immersion education for secondary students. Secondary schools, through the NASA Explorer School program, the Spitzer Space Telescope, the National Optical Astronomy Observatory, and the WISE (Wide Field Infrared Survey Explorer) Telescope Teacher Ambassador program, offer authentic research opportunities for students. Spitzer and WISE studied the sky in infrared light. Among the objects WISE studied are asteroids, the coolest and dimmest stars, and the most luminous galaxies. The lessons learned from the NASA Explorer School program and Spitzer and WISE teacher and student programs can be applied to other programs, engaging students in authentic research experiences by using data from space-borne and earth-based observatories such Kitt Peak Observatory. Several ground based telescopes at Kitt Peak Observatory study visible light from objects such as supernovae. Utilizing a student research immersion philosophy along with data analysis skills learned from the Spitzer and WISE student research programs, an analysis of supernovae distribution with respect to location in the Andromeda galaxy was conducted using images of the Andromeda galaxy taken from the WIYN 0.9 meter telescope on Kitt Peak. A comparison was made between the 12 outer fields (spiral arms) and the 4 inner fields (central bulge). Novae were found by “blinking” images of each field throughout 100 epochs of data. Blinking is a technique used to compare images of fields and noting brightness (via x,y coordinates) in one field that is not visible in the same field during a different epoch. Although the central bulge was expected to contain more supernovae due to stellar density and proximity of stars to each other, analysis of data indicates that the there is also a concentration of supernovae that appeared in outer regions. WISE Telescope funding is gratefully acknowledged. 127.02 Constraining Explosion Date and Progenitor Properties of SN 1998S with Early Photometry Chun-Shing J. Pun1, H. Poon1, Y. Qiu2, J. Wei2 1Univ. Of Hong Kong, China, 2National Astronomical Observatories, Chinese Academy of Sciences, China. 8:00 AM - 7:00 PM Essex Ballroom Constraining Explosion Date and Progenitor Properties of SN 1998S with Early Photometry Chun S.J. Pun (HKU), Helen Poon (HKU), Yulei Qiu (NAOC), Jianyan Wei (NAOC) We present early optical light curves of Type IIn Supernova 1998S (SN 1998S), including new photometry data taken by the Beijing Astronomical Observatories of China on 1998 March 2.7, or 10 days before optical maximum. The light curve is compared with analytical supernova explosion models of red supergiant stars by Nakar & Sari (2010, ApJ, 725, 904, or NS10) and Rabinak & Waxman (2011, ApJ, 728, 63, or RW11). Both models fit the data well and constrain the time of explosion of SN 1998S to be 1998 March 2.0 ± 0.3 (JD 2450874.5 ± 0.3). In addition, with these models we tried to determine the physical parameters of the progenitor star and the supernova explosion. For the NS10 model, the best-fit progenitor mass, radius, and explosion energy are 15 M_sol, 300 R_sol, and 8 x 1051 ergs respectively, while those for the RW11 model are 15 M_sol, 2000 R_sol, and 3 x 1051 ergs respectively. 127.03 Detection of Radio Transients from Supernovae Christian Schmitt1 1TCNJ. 8:00 AM - 7:00 PM Essex Ballroom A core-collapse supernova (SN) would produce an expanding shell of charged particles which interact with the surrounding magnetic field of the progenitor star producing a transient radio pulse. Approximately one supernova event per century is expected in a galaxy. The radio waves emitted are detectable by a new generation of low-frequency radio telescope arrays. We present details of an ongoing search for such events by the Eight-meter-wavelength Transient Array (ETA) and the Long Wavelength Array (LWA). 127.04 Late Phase Light Curves of SN 2005hk Jessica Crist Lair1, P. Milne2, G. Bryngelson3, M. Leising3 1Eastern Kentucky Univ., 2Steward Observatory, 3Clemson University. 8:00 AM - 7:00 PM Essex Ballroom Understanding the light curves of Type Ia Supernovae (SNe Ia) is essential to their use as standard candles in cosmological studies. Recent observations of SNe Ia have shown brighter than expected NIR emission at very late phases resulting in brighter than expected bolometric luminosity at that epoch. Also, some observations showed that the optical bands at very late phases were brighter than expected relative to the 200-330 day slope. Further study of these objects in both the optical and NIR bands is needed to better understand their behavior. We present the optical and NIR late phase light curves of the peculiar SN 2005hk as a tool to probe these questions. 127.05 Pulsar-driven Jets In Sne, Grbs, Lmxbs, Ss 433, And The Universe John Middleditch1 1LANL. 8:00 AM - 7:00 PM Essex Ballroom The model of pulsar emission through superluminally induced polarization currents, (SLIP), predicts that pulsations produced by such currents at many light cylinder radii by a rotating, magnetized body, will drive pulsations close to the axis of rotation. In SN 1987A, the possible Rosetta Stone for 99% of SNe, GRBs, ms pulsars, and SS 433, such highly collimated (<1 in 10,000) 2.14 ms pulsations, and the similarly collimated jets of particles which they drove, including 1e-6 solar masses with velocities ~0.95 c, were responsible for its very early light curve (days 3-20), its "Mystery Spot," observed slightly later (0.5 to 0.3 c, at days 30-50 and after), and still later, in less collimated form, its bipolarity. The axially driven pulsations enforce a toroidal geometry onto all early SNRs, rendering even SNe Ia unsuitable as standard candles. The numbers for Sco X-1's jet are identical, while those for SS 433 are lower (0.26 c), because of the absence of velocity "boosting" via collisions of heavy elements with lighter ones, due to the nearly pure hydrogen content of the supercritical accretion. SLIP also drives positrons from SNe to high energies, possibly accounting for the excess seen by PAMELA at scores of GeV, and predicts that almost all pulsars with very sharp single pulses have been detected because the Earth is in a favored direction where their fluxes diminish only as 1/distance, and this has been verified in the laboratory as well as for the Parkes Multibeam Survey. SLIP also predicts that GRB afterglows will be 100% pulsed at 500 Hz in their proper frame. Finally, SLIP jets from SNe of the first stars may allow galaxies to form without the need for dark matter. This work was supported in part by the Department of Energy through the Los Alamos Directed Research Grant DR20080085. 127.06 Modeling the Very Slowly Declining Type Ia Supernova 2001ay Kevin Krisciunas1, E. Baron2, P. Hoeflich3, A. M. Khokhlov4, I. Dominguez5, L. Wang1, N. B. Suntzeff1, M. Hamuy6, M. M. Phillips7 1Texas A&M University, 2University of Oklahoma, 3Florida State University, 4University of Chicago, 5Universidad de Granada, Spain, 6Universidad de Chile, Chile, 7Las Campanas Observatory, Chile. 8:00 AM - 7:00 PM Essex Ballroom Krisciunas et al. (2011) recently presented optical and near-IR photometry, plus many optical spectra of the Type Ia SN 2001ay. Its decline rate parameter dm15(B) = 0.68 mag, making it the most slowly declining Type Ia SN known to date. This object was not overluminous in optical bands, and was only slightly overluminous in the J- and H-bands. We can account for many of the observed photometric and spectroscopic features by modeling SN 2001ay with a Chandrasekhar-mass white dwarf exploding via a Pulsating Delayed Detonation (PDD) model. Our model has a relatively rapid rise time of 16 days from the time of explosion to bolometric maximum. This project was funded by the NSF through grants to the University of Chicago (AST-0709181), the University of Oklahoma (AST-0707704), Texas A&M University (AST-0708873), and Florida State University (AST-0708855). 127.07 What Drives The Sasi In Core-Collapse Supernovae? Cody Melton1, J. Blondin1 1North Carolina State University. 8:00 AM - 7:00 PM Essex Ballroom A critical component behind a supernova explosion is the spherical accretion shock instability, or SASI. Two theories describing this mechanism exist. An advective-acoustic mechanism says that entropy perturbations generated at the shock travel inward with the accretion flow at the free-fall velocity, which couple to an acoustic wave. If these perturbations amplify, the advective and acoustic waves lead to an instability. The acoustic theory states that the SASI is purely an acoustic phenomenon in which a sound wave travels around the circumference of the shock. This project attempts to resolve the debate between the two theories by observing the SASI in a regime where the timescales become disparate. Because the sound speed behind the shock is determined by the gravitational potential and the post shock flow speed is a strong function of the ratio of specific heats, gamma, the advective-acoustic mechanism has a much longer timescale for small values of gamma. We find that the timescales become highly disparate when gamma equals 1.2 and use two-dimensional simulations when gamma is 1.2 to quantify the growth rate of the instability. This will allow us to determine whether the SASI operates as an advective-acoustic or purely acoustic phenomenon. 127.08 High-Velocity Ca II in Type Ia Supernovae G. H. Marion1 1Harvard - CfA. 8:00 AM - 7:00 PM Essex Ballroom We investigate the behavior of high-velocity (HV) Ca II absorption features in spectra of Type Ia supernovae (SNe Ia). HV features are found at velocities that are several thousand kilometers per second greater than typical photospheric (PS) velocities. We present data obtained between -14d and +1d and explore similarities and differences in the velocities and line profiles for features from the Ca II H&K lines and the Ca II Infrared Triplet (IR3). The evolution of HV Ca II is revealed in spectral series obtained from individual SNe Ia and these data are compared to spectra from more than 20 additional SNe Ia. HV Ca II appears in nearly all spectra obtained earlier than -5d, but we demonstrate that there are exceptions in which HV features are not detected. We also explore diversity in HV Ca II features from SNe Ia observed at the same epochs and the behavior of HV Ca II is compared to that of other spectral features and to light curve parameters. 127.09 Classification and Redshift Determination of Pan-STARRS Supernovae with Optical Cross Correlation Filters Daniel Scolnic1, A. Riess1, M. Huber1, S. Rodney1, J. Tonry2, PS1 Science Consortium 1Johns Hopkins University, 2University of Hawaii. 8:00 AM - 7:00 PM Essex Ballroom Increasingly large photometric surveys of transient phenomena, such as Pan-STARRS, DES and LSST, will locate thousands to millions of SNe Ia candidates per year, a rate prohibitive for acquiring spectroscopy to determine each candidate’s type and redshift. Multiple supernova photometric classification/photo-z algorithms have been developed in recent years to deal with the issue of limited spectroscopic follow-up, and the Supernova Photometric Classification Challenge (Kessler et al. 2010) has shown the highest SN Ia classification purity is ~80% and redshift determination is accurate to a photo-z residual of ~0.05. In response, we have developed an economical approach to identifying SNe Ia and their redshifts using an uncommon type of optical filter with offset, multiple, narrow bandpasses that are designed to match the undulations of a Type Ia supernova spectrum. Observation of a supernova through a specially designed pair of these ‘SuperNovAe Cross-Correlation ’ (SNACC) filters measures the approximate amplitude and phase of the cross-correlation between the spectrum and a SN Ia template, a quantity typically used to determine the redshift and type of a high-redshift SN Ia. We present 98 PS1 SNe candidates that were followed-up with 4-passband SNACC filters on Subaru Telescope’s SuprimeCam. 60 of these SN candidates were classified as SNe Ia with the SNACC approach, and the subset of 20 SNe Ia with spectroscopic identifications shows, given a photometric redshift to resolve SNACC’s periodic z±0.2 ambiguity, that the SNACC rms_z~0.01. From our limited non-Ia supernova, spectroscopically verified sample, we find the bifurcation in the SNACC color space that yields a Ia classification purity of ~ 95%. We demonstrate here the cosmological significance of our SNACC sample and discuss further advantages over photometric classification/photo-z algorithms critical for photometric supernova surveys. 127.10 First Results from a Search for Nearby Cataclysmic Variables and Related Objects Julie N. Skinner1, J. Thorstensen1, S. Lépine2 1Dartmouth College, 2American Museum of Natural History. 8:00 AM - 7:00 PM Essex Ballroom We are undertaking a survey to establish an upper limit on the space density of cataclysmic variables (CVs) and related objects in the solar neighborhood through a proper-motion based approach. We start with the new Lépine-Shara proper motion survey, which is sensitive down to 40 mas/yr, and select CV candidates from this using NUV - V colors from GALEX and V - K colors from 2MASS. In our first exploratory spectroscopic run, using the 2.4m Hiltner telescope at MDM Observatory, we identified a single new CV, LSPM 03338+3320 In this presentation we give details on this new CV. Briefly, its orbital period is near 96 minutes, its spectrum shows the double-peaked Balmer emission lines characteristic of quiescent dwarf novae, and its V magnitude is near 18.2. 127.11 The Unusually Luminous Extragalactic Nova SN 2010U Ian Czekala1, R. Chornock1, E. Berger1, A. Pastorello2, G. H. Marion3, P. Challis1, J. C. Wheeler4, M. T. Botticella2, S. Smartt2, M. Ergon5, J. Sollerman5 1Harvard University, 2Queen's University Belfast, United Kingdom, 3Harvard University/UT Austin, 4UT Austin, 5Stockholm University, Sweden. 8:00 AM - 7:00 PM Essex Ballroom With the rise of time-domain astronomy and the advent of survey facilities such as Pan-STARRS, Palomar Transient Factory, and, in the future, LSST, exotic optical transients are now being found in ever-increasing numbers. These events can be distinct from the traditional categories of novae and supernovae, which are typically clustered around -8 and -18 absolute magnitudes, respectively. Objects intermediate in luminosity have been broadly labeled "supernovae imposters" because although the objects are initially bright enough to be classified as supernovae, upon further spectral analysis they mainly turn out to be luminous blue variables (LBVs). SN 2010U is one such supernovae impostor that is in fact a fast and luminous extragalactic nova (Humphreys et al. 2010). We present an early-time spectrum of SN 2010U two days after discovery that clearly identifies SN 2010U as an Fe II-type nova. Additionally, we present a complete r-band lightcurve that confirms that SN 2010U was a very fast and bright nova with absolute magnitude in excess of -10. The discovery of this exotic nova has implications for the mass of the white dwarf progenitor, accreted material, and theoretical brightness relations such as the maximum-magnitude versus rate of decline (MMRD) relationship. The supernova imposter SN 2010U probes a new phase space of transient phenomenon. 127.12 High Velocity Precessing Jet from the Water Fountain IRAS 18286-0959 Revealed by VLBA Observations Bosco Yung1, J. Nakashima1, H. Imai2, S. Deguchi3, P. J. Diamond4, S. Kwok1 1The University of Hong Kong, Hong Kong, 2Kagoshima University, Japan, 3Nobeyama Radio Observatory, Japan, 4CSIRO Astronomy and Space Science, Australia. 8:00 AM - 7:00 PM Essex Ballroom We report the multi-epoch VLBA observations of 22.2GHz water maser emission associated with the "water fountain" star IRAS 18286-0959. The detected maser emission are distributed in the velocity range from -50km/s to 150km/s. The spatial distribution of over 70% of the identified maser features is found to be highly collimated along a spiral jet (namely, jet 1) extended from southeast to northwest direction, and the rest of the features appear to trace another spiral jet (jet 2) with a different orientation. The two jets form a "double-helix" pattern which lies across ~200 milliarcseconds (mas). The maser features are reasonably fit by a model consisting of two precessing jets. The velocities of jet 1 and jet 2 are derived to be 138km/s and 99km/s, respectively. The precession period of jet 1 is about 56 years, and for jet 2 it is about 73 years. We propose that the appearance of two jets observed are the result of a single driving source with a significant proper motion. This research was supported by grants from the Research Grants Council of the Hong Kong Special Administrative Region, China, the Seed Funding Programme for Basic Research of the University of Hong Kong, Grant-in-Aid for Young Scientists from the Ministry 9 of Education, Culture, Sports, Science, and Technology, and Grant-in-Aid for Scientific Research from Japan Society for Promotion Science. 127.13 Time-resolved Optical Spectroscopy of the Classical Nova V723 Cas Thomas Vonderharr1, C. E. Woodward1, R. M. Wagner2, G. Schwarz3, L. A. Helton4, C. Hamilton-Drager5, K. A. Recine5 1University of Minnesota, 2Large Binocular Telescope Observatory, 3American Astronomical Society (Corporate Offices), 4Stratospheric Observatory for Infrared Astronomy, 5Dickinson College. 8:00 AM - 7:00 PM Essex Ballroom We present the results of time-resolved optical spectroscopy of the classical nova and super-soft X-ray source V723 Cas (Nova Cas 1995). The spectra were obtained at the Steward Observatory Bok 2.3-m telescope (range: 4180-5320 Angstroms) on Kitt Peak and at the MDM Observatory Hilter 2.4-m telescope (range: 4000-7500 Angstroms) in 2007, 2008, and 2010. Both sets of spectra were obtained at a spectral resolution of about 2 Angstroms. Exposure times of the individual spectra were about 20 minutes which is short compared to the 16.6-hour binary orbital period, thus minimizing velocity smearing of spectral features. V723 Cas is an unusual system, being an active super-soft X-ray source for more than 15 years since the 1995 outburst, in contrast to the median X-ray turn off time of only 1.4 years. This may be indicative of steady hydrogen burning on the white dwarf due to renewed accretion (Ness et al. 2008, AJ, 135, 1328). Phasing the individual spectra to the 16.6-hour binary photometric orbital period (Goranskij et al. 2007, Ast. Bull. 62, 125), we find that the Balmer emission lines exhibit a double-peaked accretion disk line profile convolved with a variable Gaussian emission line S-wave component. The He II 4686 emission line exhibits phase-dependent line profile variations as well. We have modeled both emission line profiles with a double-peaked accretion disk line component assuming different disk properties and an independent Gaussian component. The results of our line profile modeling compared to the orbital photometric behavior of V723 Cas are presented and we discuss the interpretation of our synoptic observations in the context of the post-outburst evolution of super-soft X-ray sources and this unusual classical nova. 127.14 Analysis of the High Dispersion Spectra of the Planetary Nebula NGC 7027 Siek Hyung1, S. Lee1, M. Otsuka2, A. Tajitsu3 1ChungBuk National Univ., Korea, Republic of, 2Space Telescope Science Institute, 3Subaru Telescope. 8:00 AM - 7:00 PM Essex Ballroom Using the high dispersion spectra taken with the Keck I HIRES in 1998 August 13 - 15, we analyzed the electron density and electron temperature variation of the nebular gas shell of the planetary nebula NGC 7027. The employed slit dimensions and the observed wavelength regions are the following four settings: 1) 14" x 0.862" (8530 - 6309A; red collimator); 2) 10" x 0.862" (5130 - 7475A; red collimator); 3) 7" x 0.862" (3100 - 4100A; red collimator); and 4) 3.5" x 0.862" (3450 - 5900A; blue collimator). Since these employed slit lengths were shorter than the dimension of NGC 7027, we shifted the slit entrance of the HIRES on a nebular image and obtained various diagnostic spectral lines from the major and minor axes of the nebula. Many diagnostic lines, such as [N II]5755, 6583; [O III]4363, 4959+5007; [O II]3726, 3729; and [Ar IV]4711, 4740 that were useful in finding the physical conditions, were obtained. We present the line ratios and the anlayzed physical conditions in the main shell of the nebula that show some variation; log Ne = 4.25 - 4.75 cm-3 ([S II], [Cl III], & [Ar IV]) and Te = 13000 - 18000 K ([O III]). Although the analysis shows fluctuations in the physical condition, we postpone any conclusion on the existence of fine-structures in the main shell, responsible for high-density or high electron temperature components. 127.15 The Symbiotic Nature of M2-9 Jerica M. Green1, B. Balick1, J. Lutz1 1University of Washington. 8:00 AM - 7:00 PM Essex Ballroom We present moderate resolution deep stellar spectra of the object Minkowski 2-9 (M2-9) also known as the "Butterfly" or the Twin-Jet Nebula. M2-9's central star has been identified as a symbiotic star because bright H-alpha and weaker [NII] emission lines have been seen in its spectra, and its near infrared flux is more similar to symbiotic stars than planetary nebulae. Our calibrated and extracted spectra show that the star has dozens of faint emission lines, and those lines probably arise in a very dense circumstellar envelope. We compare the features from the central star of M2-9 to some well-known symbiotic stars. 127.16 Properties and Spatial Distribution of Dust Emission in the Crab Nebula Tea Temim1, G. Sonneborn2, E. Dwek2, R. G. Arendt3, R. D. Gehrz4, P. O. Slane5 1NASA/GSFC/ORAU, 2NASA/GSFC, 3CRESST/UMBC, 4Univ. of Minnesota, 5Harvard-Smithsonian, CfA. 8:00 AM - 7:00 PM Essex Ballroom The nature and quantity of dust produced in supernovae (SNe) is still not understood. Recent infrared (IR) observations of freshly-formed dust in supernova remnants (SNRs) have yielded significantly lower dust masses than predicted by theoretical models and high redshift observations. The Crab Nebula's pulsar wind is thought to be sweeping up freshly-formed SN dust along with the SN ejecta. The evidence for this dust was found in the form of an IR bump in the integrated spectrum of the Crab and in extinction against the synchrotron nebula that revealed the presence of dust in the filament cores. We present the first spatially resolved emission spectra of dust in the Crab Nebula acquired with the Spitzer Space Telescope. The IR spectra are dominated by synchrotron emission and show forbidden line emission from both sides of the expanding nebula, including emission from S, Si, Ne, Ar, Fe, and Ni. We extrapolated a synchrotron spectral cube from the Spitzer 3.6 and 4.5 micron images, and subtracted this contribution from our spectral data to produce a map of the residual continuum emission from dust. The emission appears to be concentrated along the ejecta filaments and is well fitted by astronomical silicates at an average temperature of 52 K. We discuss the spatial variations in the dust spectrum across the nebula and revise the total dust mass estimates. 127.17 Extending The Sma Spectral-line Survey Of Irc+10216 In The 400 Ghz Band Nimesh A. Patel1, K. Young1, C. Gottlieb1, P. Thaddeus1, K. Menten2, M. McCarthy1, E. Keto1, R. Wilson1 1Harvard-Smithsonian Center for Astrophysics, 2Max Planck Institute for Radio Astronomy, Germany. 8:00 AM - 7:00 PM Essex Ballroom Interstellar dust grains are thought to evolve in the colder regions of space from the gas and solids there, material believed to come from Asymptotic Giant Branch (AGB) stars. IRC+10216 is a well studied such star with high mass loss. Close to the Sun (~150 pc), it is an ideal place to study the physical and chemical processes in AGB circumstellar envelopes. Using the Submillimeter Array (SMA), we recently carried out the first interferometric spectral line-survey of IRC+10216 in the 345 GHz band, with an angular resolution of 3"x2". This survey has led to the discovery of many narrow lines of molecular emission, implying expansion velocities of ~4 km/s (in contrast with the typical value of the expansion velocity of 14.5 km/s known from previous surveys). Maps of these lines show that they are produced in the inner envelope, within 60 AU of the star, where the stellar wind is still being accelerated. Following this line survey in the 294-355 GHz frequency range, we are now extending the frequency coverage to 396-420 GHz. We will add higher frequency transitions for several molecules that were detected in our 345 GHz line survey, allowing us to better characterize the physical conditions in the inner circumstellar envelope. We will be able to derive abundances of several molecular species, for comparison with chemical models. Continuum fluxes at higher frequencies will help constrain the SED due to dust emission. These observations partially fill the gap between our previous survey (379-355 GHz) and the recently published survey at even higher frequencies (490-1900 GHz) with the Herschel HIFI. The SMA is a joint collaboration between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics. 128 Extrasolar Planets: Detection and Characterization Poster Session Essex Ballroom 128.01 Early Constraints From The MEarth Project On The Occurrence Rate Of Super-Earth And Neptune-sized Exoplanets Orbiting Mid-to-Late M Dwarfs Zachory K. Berta1, D. Charbonneau1, C. J. Burke1, J. A. Dittmann1, E. E. Falco2, J. Irwin1, E. Newton1, P. Nutzman3 1Harvard-Smithsonian Center for Astrophysics, 2Smithsonian Astrophysical Observatory, 3University of California, Santa Cruz. 8:00 AM - 7:00 PM Essex Ballroom Using an array of modest ground-based telescopes, the MEarth Project is photometrically monitoring nearby mid-to-late M dwarfs with sufficient precision to detect transiting exoplanets as small as twice the radius of the Earth. Having a reliably characterized input catalog of 2,000, high proper-motion, low-mass stars enables us to simulate our planet detection sensitivity in detail and place limits on the occurrence rate of planets orbiting mid-to-late M dwarfs. I will present preliminary results from a statistical analysis of the first 1,000 M dwarfs with MEarth light curves, including constraints on the fraction of such stars that may host super-Earth or Neptune-sized planets. Neither the Kepler Mission nor the optical radial velocity surveys probe substantial numbers of stars cooler than 3500K; the MEarth Project's occurrence rate estimates are highly complimentary to these other large efforts. Our statistical estimates will continue to improve as MEarth collects more data and we progress toward our ultimate goal of detecting a transiting super-Earth in the habitable zone of its host M dwarf. Importantly, thanks to its favorable planet-to-star contrast ratio, the atmosphere of such a habitable planet could be spectroscopically characterized using JWST. 128.02 Modeling The Detectability Of Exoplanets For The Palomar Extreme Adaptive Optics Palm-3000 System. Rahul Patel1, S. Metchev1 1SUNY Stony Brook. 8:00 AM - 7:00 PM Essex Ballroom In this study, we present the projected capabilities and detection limitations for the PALM-3000 Extreme Adaptive Optics system to directly image super-Jupiter planets around nearby stars. PALM-3000 is the new adaptive optics system for the Palomar 5 m telescope, which employs a 3366 - actuator deformable mirror and is expected to deliver contrast ratios near 107 at 1 arc second from bright stars. The PALM-3000 system will be an upgrade from the current Adaptive Optics system at Palomar and commissioning will begin in the summer of 2011. Planetary and orbital parameters (mass, eccentricity, semi-major axis) were randomly sampled from known distributions, which have been established or extrapolated from radial velocity observations. Parent stars were modeled in accordance with the stellar initial mass function (IMF) and given randomized ages and distances from Earth. Probability for detection was modeled using a Monte-Carlo simulation written in IDL. Projected contrast curves in the H band for PALM-3000 were used as the constraints for planetary detection. 128.03 Improving Transit Predictions of Known Exoplanets with TERMS Stephen R. Kane1, D. Ciardi1, D. Dragomir1, D. Fischer2, G. Henry3, A. Howard4, E. Jensen5, G. Laughlin6, S. Mahadevan7, G. Pilyavsky7, K. von Braun1, J. Wright7 1NASA Exoplanet Science Institute, Caltech, 2Department of Astronomy, Yale University, 3Tennessee State University, 4Department of Astronomy, University of California, 5Dept of Physics & Astronomy, Swarthmore College, 6UCO/Lick Observatory, University of California, 7Department of Astronomy and Astrophysics, Pennsylvania State University. 8:00 AM - 7:00 PM Essex Ballroom Transiting planet discoveries have yielded a plethora of information regarding the internal structure and atmospheres of extra-solar planets. These discoveries have largely been restricted to the low-periastron distance regime due to the bias inherent in the geometric transit probability. Monitoring known radial velocity planets at predicted transit times is a proven method of detecting transits, and presents an avenue through which to explore the mass-radius relationship of exoplanets in new regions of period/periastron space for the brightest exoplanet host stars. Here we describe transit window calculations for known radial velocity planets, techniques for refining their transit ephemerides, and present results for radial velocity planets which have been successfully monitored during predicted transit times. These methods are currently being implemented by the Transit Ephemeris Refinement and Monitoring Survey (TERMS). 128.04 Warm Spitzer Secondary Transit Photometry of Hot Jupiters HAT-P-6b, HAT-P-8b and XO-4b Kamen 0. Todorov1, D. Deming2, H. Knutson3, A. Burrows4, P. Sada5, E. Agol6, J. Desert7, J. J. Fortney8, D. Charbonneau7, N. B. Cowan9, G. Laughlin8, J. Langton10, A. P. Showman11, N. K. Lewis11 1The Pennsylvania State University, 2NASA’s Goddard Space Flight Center, 3University of California at Berkeley, 4Princeton University, 5University of Monterrey, Mexico, 6University of Washington, 7Harvard-Smithsonian Center for Astrophysics, 8University of California at Santa Cruz, 9Northwestern University, 10Principia College, 11University of Arizona. 8:00 AM - 7:00 PM Essex Ballroom An increasing number of transiting exoplanets have been observed at secondary eclipse. By measuring the depth of these eclipses at different wavelengths it is possible to distinguish between planets that have a temperature inversion in the upper layers of their atmospheres and ones that do not. We observed XO-4b, HAT-P-6b and HAT-P-8b during secondary eclipse with the IRAC instrument on Warm Spitzer at 3.6 and 4.5 microns. We compare the resulting eclipse depths to atmospheric models with and without temperature inversions, and thereby place constraints on the properties of their day-side atmospheres and heat redistribution efficiencies. The XO-4b and HAT-P-6b eclipse depths agree best with inverted models, while HAT-P-8b exhibits no temperature inversion. Knutson et al. (2010) hypothesized a correlation between lack of a temperature inversion and host star activity. Also, Cowan & Agol (2011), investigated the dependence between planetary effective temperatures, assuming no redistribution, and heat redistribution efficiency, finding that the hottest planets re-distribute heat inefficiently. We compare our planets with the Knutson and Cowan-Agol relations, and we find that they are consistent with the Knutson et al. activity hypothesis, but they are not hot enough to test the Cowan & Agol hypothesis. 128.05 New Analyzing Tools for the Rossiter-McLaughlin Effect TERUYUKI HIRANO1, J. N. WINN1, S. ALBRECHT1, Y. SUTO2, N. NARITA3, B. SATO4 1MIT, 2The University of Tokyo, Japan, 3NAOJ, Japan, 4Tokyo Institute of Technology, Japan. 8:00 AM - 7:00 PM Essex Ballroom The Rossiter-McLaughlin (RM) effect is a radial velocity anomaly during a planetary transit caused by a partial occultation of the rotating stellar disk. Measurements of the RM effect tell us the sky-projected angle between the stellar spin axis and the planetary orbital axis. This angle is associated with the dynamical history of close-in planets and so very important to test theoretical hypotheses regarding planetary migration. So far, the interpretation of the radial velocity anomaly has been based mainly on analytic approximations with limited applicability, or with numerical simulations. We have developed a new and more accurate analytic formula which specifies the RM velocity anomaly in terms of the position of the planet, the stellar spin velocity, and other intrinsic line parameters such as macroturbulence. Although our formula is derived for the case in which the radial velocity anomaly is derived from a cross-correlation analysis, the formula also gives a good agreement with the simulated results based on the forward-modeling approach that is used for spectra obtained with an iodine gas cell. We discuss the results of reanalyses of the RM effect for several selected transiting systems with our new analytic formula and show that it is a useful new tool for precise estimations of planetary parameters. 128.06 Improving the RV Precision of HET/HRS Xuesong Wang1, J. T. Wright1 1Pennsylvania State University. 8:00 AM - 7:00 PM Essex Ballroom We present our work on improving the radial velocity precision of the High Resolution Spectrograph (HRS) on Hobby-Eberly Telescope (HET). This stable, fiber-fed spectrograph had a reported RV precision of around 3-5 m/s. Our current precision is 3m/s, and we are pushing this limit towards 1m/s upon HET/HRS upgrades and improvement of our pipeline. Some results on newly discovered exoplanets by this pipeline are also presented. 128.07 Null Detection of a Substellar Companion to HD 149382 Jackson Norris1, J. T. Wright1, R. A. Wade1, S. Mahadevan1 1The Pennsylvania State University. 8:00 AM - 7:00 PM Essex Ballroom Soker (1998) argued that a substellar companion may significantly influence the evolution of the progenitors of sdB stars. Recently, Geier et al. (2009) have claimed that the bright sdB star HD 149382 hosts a substellar companion with a period of 2.391 days and mass of 8-23 Jupiter masses. If true, this would have important implications for the evolution of the progenitors of sdB stars as well as the source of the UV-excess seen in elliptical galaxies. In order to verify this putative substellar companion, we obtained 40 exposures of HD 149382 over 17 days with the High Resolution Spectrograph at the Hobby-Eberly Telescope. Our data are inconsistent with the claim by Geier et al. and support the absence of the substellar companion. 128.08 IRTF/SpeX NIR Emission Spectra of WASP-1b Heather Bloemhard1, M. Creech-Eakman1, P. D. Deroo2, M. Zhao2 1New Mexico Institute of Mining and Technology, 2Jet Propulsion Laboratory, California Institute of Technology. 8:00 AM - 7:00 PM Essex Ballroom Of the more than 500 known exoplanets, the detailed chemical composition of only a handful of exoplanet atmospheres is known. We endeavor to remedy this imbalance by using ground-based spectroscopy, which has been demonstrated to reliably reproduce space-based results (Swain et al., Nature 463, 2010) while obtaining new and unexpected information. Our IRTF/SpeX SXD (0.8-2.4 micron cross-dispersed) observations of two secondary eclipses of the exoplanet WASP-1b, obtained September and October 2010, will be used to accomplish two main goals: first, to extend the application of exoplanet ground-based spectroscopy to a wider range of targets than are presently characterized; and second, to probe the temperature structure and begin to characterize the composition of the dayside of the atmosphere. We will show our data reduction steps and initial results based on the reduction method introduced by the Exospec team (Swain et al., Nature 463, 2010) WASP-1b is a 1.44±0.04 RJ, 0.89±0.11 MJ exoplanet in a 2.52 day orbit around its parent star (Cameron et al., MNRAS 375, 2007; Charbonneau et al., ApJ 638, 2007). It has a very low density, which puts it in a group of highly irradiated hot-Jupiters with overly inflated radii known as pM class exoplanets. Theory predicts that we should expect to find a thermal inversion, as well as evidence of H2O and CO (Fortney et al., ApJ, 678, 2008). However, the reason for the inflated radii of these exoplanets is still a matter of great debate (Miller et al., ApJ 702, 2009; Spiegel et al., ApJ 699, 2009; Madhusudhan & Seager, ApJ 725, 2010; Guillot, A&A 520, 2010); determining the structure and composition of the atmospheres of this class of exoplanets may help us sort among competing theories as to the structure and source of the inflated radius. 128.09 X-Ray Observations of Hot Jupiters Scott J. Wolk1, I. Pillitteri1, O. Cohen1, V. Kashyap1, J. Drake1, C. M. Lisse2 1SAO, 2JHU. 8:00 AM - 7:00 PM Essex Ballroom The effect of stellar X-rays on their nearby gas-giant planets appear to be significant. The X-rays have been cited at the cause of excess heating of the planet which can induce mass loss. Further, several lines of argument indicate that the magnetic fields of the two bodies can interact. We report on XMM-Newton observations of the planetary host star HD 189733. The system has a close-in planet and it can potentially affect the coronal structure via interactions with the magnetosphere. We have obtained X-ray spectra and light curves during the primary transit and secondary eclipse. During transit, only variability due to weak flares is recognized. During the eclipse, we observed a significant softening of the X-ray spectrum at a level of ~3σ. Furthermore, we observed the most intense flare recorded at either epoch. This flare occurred 3 ks after the end of the eclipse. The flare decay shows several minor ignitions perhaps linked to the main event and hinting at secondary loops that are triggered by the main loop. Magnetohydrodynamic (MHD) simulations show that the magnetic interaction between planet and star enhances the density and the magnetic field in a region between the planet and the star because of their relative orbital/rotation motion. X-ray observations and model predictions are globally found in agreement, despite the quite simple MHD model and the lack of precise estimate of parameters including the alignment and the intensity of stellar and planetary magnetic fields. We discuss the significance of higher area and high spectral resolution on such observations. 128.10 The Value of K2 in Determining Interior Composition of Terrestrial Planets Adam Maxwell1, D. Ragozzine2, L. A. Rogers3, S. Seagar4, L. Zeng5 1Cambridge School Of Weston, 2Institute for Theory and Computation, Smithsonian Astrophysical Observatory, 3Department of Physics, massachusetts Institute of Technology, 4Department of Earth, atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 5Department of Astronomy, Harvard University. 8:00 AM - 7:00 PM Essex Ballroom The composition of exoplanets is interesting for theoretical reasons and for possible implications of planet habitability. Currently, only the mass and radius are able to be used to estimate the composition of well-understood transiting exoplanets. With only these parameters to depend on, there is still significant uncertainty in the interior composition, as there are many possible interior compositions for a planet with a given mass and radius. Another observable parameter that could be used is k2, the planetary Love number, a measurement of the central condensation of a planet (equivalent to J2) that could be measurable in the future via repeated transit measurements (Ragozzine & Wolf 2009, Batygin et al. 2009). We have developed a program that calculates the k2 of planets from their interior density distribution by numerically integrating the Clairaut-Radau equation. The model has been applied to a large sample of terrestrial planets ranging from 0.5-8 Earth masses and 0.5-5 Earth radii. These sample planets have a wide variety of compositions iron, rock, ice, and gas (from Rodgers & Seager 2009 and Zeng & Seager 2008) to explore how k2 can be used to break the degeneracy of interior composition, even for model planets with well-known masses and radii (see also Kramm et al. 2011). We will present the value of k2 measurements in narrowing the range of possible interior structures of terrestrial planets. We will make the software that calculates k2 available for theorists to use in related studies of exoplanets. 128.11 The University of Arizona Astronomy Club Observations of Transiting Extrasolar Planets TrES-3b and TrES-4b Jake Turner1, K. Hardegree-Ullman1, B. Smart1, A. Walker-LaFollette1, K. Cunningham1, E. E. Hardegree-Ullman2, B. Crawford1, J. Mueting1, T. Carleton1, K. Schwarz1, A. Robertson1, B. Guvenen1, A. Towner1, C. Austin1, T. Henz1, D. Keys1, K. Johnson1 1University of Arizona, 2Rensselaer Polytechnic Institute. 8:00 AM - 7:00 PM Essex Ballroom Using the Steward Observatory 61" Kuiper Telescope, The University of Arizona Astronomy Club observed extrasolar planets TrES-3b and TrES-4b. We observed the planets with the Harris-B, V, and R filters as they transited their parent stars during the months of May-July 2009. The main goal of this project was to get undergraduates involved with a research astronomy project and allow them to gain experience beyond what they would receive in the classroom. Many of the team members were introduced to astronomical observing techniques and data reduction using IRAF. Part of the project involved determining the optimum number of flat-field and bias frames required for image calibrations. With our results, we have been able to confirm and refine previously published values for the planets' orbital inclination, mass, radius, and density. 129 Molecular Clouds, HII Regions, Interstellar Medium and Dust Poster Session Essex Ballroom 129.01 Correlation between Dust and Gas in the Magellanic Clouds Julia Roman-Duval1, K. D. Gordon1, M. Meixner1, HERITAGE 1Space Telescope Science Institute. 8:00 AM - 7:00 PM Essex Ballroom In the past 15 years, there has been considerable effort to estimate the mass of H2 from dust FIR measurements in order to constrain the star formation law in low metallcity galaxies, where the low dust abundance and subsequent lack of shielding from ambient radiation makes photo-dissociated CO an ineffective tracer of molecular gas. This method relies on an estimate of the gas-to-dust ratio (GDR) from gas H I 21 cm, CO, and dust FIR observations either in diffuse regions where no H2 is expected to exist, or in the densest regions where CO is known to trace H2 and the value of the X factor can be derived simultaneously with the GDR. Thus, the GDR is assumed to be independent of local environment and density. In reality, dust destruction by shocks in the diffuse ISM, mantling in the dense ISM, and variations in the dust production rate with star formation activity can lead to significant (factor 2-3) variations in the GDR and bias this estimate of the H2 mass. In addition, the dust emissivity is assumed to be constant, although it actually depends on density because grain growth in dense molecular clouds increases the emissivity by a factor of a few. Here, we investigate systematic variations of the GDR, dust emissivity, and X factor with column density, radiation field, and star formation activity based on the correlation between gas mass derived from CO and H I 21 cm observations and FIR emission from the HERschel Inventory of The Agents of Galactic Evolution (HERITAGE) project in the Magellanic Clouds. We show that the dust-gas correlation cannot be explained by a single GDR, dust emissivity, or X factor, and we use a simple model of GDR and dust emissivity variations with column density of explain the observed trends. 129.02 Level Crossing Analysis of the I-GALFA H I 21-cm Line Maps of the Galaxy Geumsook Park1, B. Koo1, S. J. Gibson2, J. Kang3, K. A. Douglas3, J. E. G. Peek4, E. J. Korpela5, C. E. Heiles5 1Seoul National University, Korea, Republic of, 2Western Kentucky University, 3Arecibo Observatory, Puerto Rico, 4Columbia University, 5University of California. 8:00 AM - 7:00 PM Essex Ballroom Recent high-resolution observations reveal that the HI structure of the Galaxy is quite complex with numerous filaments and clumps. Statistical techniques are essential to describe and compare these complex morphologies, which can give insights on how the energy is injected and dissipated in the interstellar medium. We use the level-crossing statistics (LCS) to examine the HI structure in the I-GALFA HI survey data. The LCS is complimentary to the genus statistics. Like the Genus, the LCS can discriminate specific topologies such as clumpy or hole-like field, but in addition it can describe aligned or filamentary structures. The I-GALFA HI survey covers the first quadrant of the Galaxy including significant latitude range (about 12 degree up and down the plane) with high resolution (about 3.35 arcmin), so that it provides a great opportunity to observe the fine details of HI both in the inner and outer Galaxy. We select sample regions of spiral arms in the inner and outer Galaxy and derive their LCS properties. The LCS curves of most areas show positive tails and large skewnesses, which implies that the HI morphology is significantly clumpy. In the outer spiral arm, the LCS curves in longitude and latitude directions show considerable difference and indicate that the HI gases are aligned along the Galactic plane. This appears to be consistent with the low stellar activity in the outer Galaxy. We will also present the LCS properties with varying spatial scales. 129.03 Testing Extinction Distances to Massive Star-Forming Regions Against Maser Parallax Distances Jonathan B. Foster1, J. Stead2, R. Benjamin3, J. Jackson1 1Boston University, 2University of Leeds, United Kingdom, 3University of Wisconsin Madison. 8:00 AM - 7:00 PM Essex Ballroom Accurate distances to massive star-forming regions are critical for converting observed values into physical quantities. Recent parallax measurements of masers within massive star-forming regions have established a reliable set of distances to a number of clouds in the first quadrant, ranging from 1 to 6 kpc. Unfortunately, maser parallax measurements are difficult to make and only possible in regions which exhibit bright masers. We report on a study using these distances to validate and calibrate two different near-infrared extinction distance methods which combine a galactic model with UKIDSS/GPS and 2MASS data. One method uses star counts of blue foreground stars, and the other uses red giant stars as standard candles. We also compare the parallax and extinction distances to kinematic distances using a variety of rotation curves. Support for this project provided by a grant from NASA. 129.04 Detection of Thermal 2 cm and 1 cm Formaldehyde Emission in NGC 7538 Liang Yuan1, E. D. Araya1, P. Hofner2, S. Kurtz3, Y. Pihlstrom4 1Western Illinois University, 2New Mexico Tech, 3CRyA, Universidad Autonoma de Mexico, Mexico, 4University of New Mexico. 8:00 AM - 7:00 PM Essex Ballroom Formaldehyde is a tracer of high density gas in massive star forming regions. The K-doublet lines from the three lowest rotational energy levels of ortho-formaldehyde correspond to wavelengths of 6, 2 and 1 cm. Thermal emission of these transitions is rare, and maser emission has only been detected in the 6 cm line. NGC 7538 is an active site of massive star formation in the Galaxy, and one of only a few regions known to harbor 6 cm formaldehyde (H2CO) masers. Using the NRAO 100 m Green Bank Telescope (GBT), we detected 2 cm H2CO emission toward NGC 7538 IRS1. The velocity of the 2 cm H2CO line is very similar to the velocity of one of the 6 cm H2CO masers but the linewidth is greater. To investigate the nature of the 2 cm emission, we conducted observations of the 1 cm H2CO transition, and obtained a cross-scan map of the 2 cm line. We detected 1 cm emission and found that the 2 cm emission is extended (greater than 30"), which implies brightness temperatures of ∼0.2 K. Assuming optically thin emission, LTE, and that the 1 cm and 2 cm lines originate from the same volume of gas, both these detections are consistent with thermal emission of gas at ∼30 K. We conclude that the 1 cm and 2 cm H2CO lines detected with the GBT are thermal, which implies molecular densities above ∼105 cm-3. LY acknowledges support from WIU. PH acknowledges partial support from NSF grant AST-0908901. 129.05 Methyl Cyanide Observations of Massive Protostars Viviana A. Rosero-Rueda1, P. Hofner2, S. Kurtz3, J. Bieging4, E. Araya5, E. Jordan1 1NMT, 2NMT & NRAO, 3CRyA, Mexico, 4UofA, 5WIU. 8:00 AM - 7:00 PM Essex Ballroom Massive stars are formed in warm, dense condensations in molecular clouds known as hot molecular cores (HMCs). Despite their importance, the role that HMCs play in the evolution of massive stars is currently not well understood due to a lack of observational data and hence physical properties. Molecular transitions in the HMCs are used to deduce the physical properties of these regions. In this study, observations of CH3CN in the J=12-11 transition in the 1mm band for 9 massive star forming regions were made using the Arizona Radio Observatory 10m Telescope on Mt. Graham, AZ (SMT). We report results of the derivation of column densities and temperatures of the observed sources using the population diagram technique, as well as a kinematic analysis based on our high resolution spectra. This research is supported by NSF grant AST-0908901. 129.06 Simulations of High Velocity Clouds: High-Velocity High-Stage Ions Kyujin Kwak1, D. B. Henley1, R. L. Shelton1 1Univ. of Georgia. 8:00 AM - 7:00 PM Essex Ballroom We present the results of hydrodynamic simulations of high velocity clouds (HVCs) carried out using FLASH. The simulations self-consistently trace the non-equilibrium ionization evolution of carbon, nitrogen, and oxygen in a realistic HVC geometry, in which a cool dense spherical cloud moves through hot, tenuous halo gas. In our simulations, H I is ablated from the clouds through shear instabilities and undergoes turbulent mixing with the hot ambient gas. High-stage ions (C IV, N V, and O VI) are abundant in these turbulent mixing layers. We investigate a suite of models with a range of model parameters (cloud size, cloud velocity, cloud density). The simulations run for 60-240 Myr, depending on the model parameters. We find that the cloud's initial velocity does not affect the rates of H I ablation or ionization or high-stage ion production over a wide range of velocities, from subsonic through transonic to supersonic. However, we find that the cloud's initial size does affect the rate at which cloud material is ablated and/or ionized: a smaller cloud loses its H I mass relative to its initial mass more rapidly than a larger cloud. We also find that large HVCs are able to survive as far as the Galactic disk in the form of neutral hydrogen and thus fuel star formation. Our models compare well with Complex C observations in terms of the observed high-stage ion column densities, the trend between N(O VI)/N(H I) and N(H I), the ion-to-H I ratios, and the ion-to-ion ratios. 129.07 Simulations of High Velocity Clouds: X-ray Signatures Robin L. Shelton1, K. Kwak1, D. Henley1 1Univ. of Georgia. 8:00 AM - 7:00 PM Essex Ballroom High velocity clouds (HVCs) have been observed in a variety of wavebands, from radio to ultraviolet. Even excess X-rays have been reported near some HVCs. Here, we examine possible production scenarios for the HVC-induced X-rays. Using detailed hydrodynamic and magnetohydrodynamic simulations of HVCs interacting with environmental gas, we examine two scenarios. In the first, the clouds travel fast enough to shock-heat warm environmental gas. In the second, the clouds travel through and mix with hot ambient gas. The X-ray productivity of the first scenario depends strongly on the radiative cooling rate. If it is quenched, then the shock-heated ambient gas is X-ray emissive, producing bright X-rays in the 1/4 keV band and some X-rays in the 3/4 keV band from O VII ions. If, in contrast, the radiative cooling rate is similar to that of collisional ionizational equilibrium plasma with solar abundances, then the shocked gas quickly cools and becomes X-ray dim. The mixed gas in the second scenario is X-ray dim. Only when the cloud moves fast enough to shock-heat the ambient medium and radiative cooling is quenched do we see noticeable fluxes of X-rays. We present the predicted 1/4 keV countrates, O VII intensities, and O VII column densities for comparison with observations. We acknowledge the Chandra Theory Program for funding. 129.08 Parker Instabilities with Magnetic Cross Field Diffusion of Cosmic Rays Chih-Yueh Wang1, Y. Lo1, C. Ko2 1Chung-Yuan Christian University, Taiwan, 2National Central University, Taiwan. 8:00 AM - 7:00 PM Essex Ballroom Parker instability arises from the presence of magnetic fields in a plasma in a gravitational field such as the interstellar medium (ISM), wherein the magnetic buoyant pressure expels the gas and causes the gas to move along the field lines. The subsequent gravitational collapse of the plasma gas is thought to be responsible for the formation of giant molecular clouds in the Galaxy. The process of mixing in the ISM near the Galactic plane is investigated. The initial ISM is assumed to consist of two fluids: plasma gas and cosmic-ray particles, in hydrostatic equilibrium, coupled with a uniform, azimuthally-aligned magnetic field. After a small perturbation, the unstable gas aggregates at the bottom of the magnetic loops and forms dense blobs. The growth rate of the instability decreases as the coupling between the cosmic rays and the plama becomes stronger (meaning a smaller cosmic-ray diffusion coefficient). The mixing is enhanced by the cosmic-ray diffusion, while the shape of the condensed gas depends sensitively on the initial equilibrium conditions. The perpendicular or cross field lines diffusion coefficient kappa_cross is often substantially smaller than the parallel coefficient kappa_0, only around 2%-4% of kappa_0. However, even with the minimum cross field diffusion, the mixing is significantly enhanced. The galactic wind flow perpendicular to the galactic disk may be greatly facilitated by Parker instabilities through the cross field diffusion of cosmic rays. 129.09 A Survey of N2H+ Toward the Serpens Molecular Cloud Kevin Hardegree-Ullman1, Y. L. Shirley1 1University of Arizona. 8:00 AM - 7:00 PM Essex Ballroom The Serpens Molecular Cloud, at a distance of ~230pc, is star forming region containing 35 dense protostellar and starless cores, as identified in the c2d 1.1mm continuum survey (Enoch et al. 2007, ApJ, 666, 982). These cores are in the process of forming low and intermediate-mass stars, so they provide a unique test bed to study gas phase evolution in molecular clouds. Using the Arizona 12-m radio telescope, we observed the J=1-0 rotational transition of N2H+ in order to calculate column densities in the cloud. We mapped N2H+ abundance in the vicinity of three major star forming filaments, previously identified in the 1.1mm survey, and found N2H+ in protostellar cores is enhanced by three times compared to that of starless cores. Comparison of N2H+ distribution with that of 12CO and 13CO found by Bieging et al. (in prep) will shed further light on gas phase evolution within Serpens. This research is supported by the Arizona NASA Space Grant Consortium. 129.10 Pairwise Correlations Of Eight Strong DIBs And N(H), N(H2), And E(B-V) Scott David Friedman1, D. G. York2, B. J. McCall3, J. Dahlstrom4, P. Sonnentrucker1, D. E. Welty3, M. M. Drosback5, L. M. Hobbs6, B. L. Rachford7, T. P. Snow8 1STScI, 2University of Chicago, 3University of Illinois, 4Carthage College, 5University of Virginia, 6Yerkes Observatory, 7Embry-Riddle Aeronautical University, 8University of Colorado. 8:00 AM - 7:00 PM Essex Ballroom We establish correlations between equivalent widths of eight diffuse interstellar bands (DIBs), and examine their correlations with N(H), N(H2), and E(B-V). The DIBs are centered at 5780.5, 6204.5, 6283.8, 6196.0, 6613.6, 5705.1, 5797.1, and 5487.7, in decreasing order of Pearson’s correlation coefficient with N(H), which range from 0.96 to 0.82. We find the equivalent width of 5780.5 is better correlated with column densities of H than with E(B-V) or H2, confirming earlier results, and the same is true for six of the seven other DIBs presented here. Despite this similarity, the eight strong DIBs chosen are not correlated well enough with each other to suggest they come from the same carrier. These DIBs are more likely to be associated with H than with H2, and hence are not preferentially located in the densest, most UV shielded parts of interstellar clouds. The correlations may be useful in deriving interstellar parameters, such as N(H) from W(5780.5), when more direct methods are not available. Our future plans include closer examination the excellent correlation between 5705.1 and 5780.5 (almost as good as the near perfect correlation of 6613.6 with 6196.0), and on precise measurements of broad DIBS (e.g. 4428.83, 4881.06) and inclusion of these better measurements in correlation studies with the main DIBs noted in this poster. 129.11 C18O and N2H+ Gas Phase Observations Toward Rossano Cloud B in the Corona Australis Molecular Cloud Complex Emily E. Hardegree-Ullman1, D. Horne1, D. Whittet1, J. Harju2, J. Spizuco1, P. Mayeur1 1Rensselaer Polytechnic Institute, 2University of Helsinki, Finland. 8:00 AM - 7:00 PM Essex Ballroom Chemical evolution of organic molecules essential to life begins in cold, pre-stellar molecular cloud cores. Given the relative lack of incident radiation, chemical reactions in these cores are dependent on interactions between their gas phase material and dust/ices. C18O and N2H+ in particular are two constituents in many pre-stellar cores that are detectable in their gas phase at radio wavelengths. Using data collected with the Swedish-ESO Submillimeter Telescope (SEST), we have observed the abundance and distribution of molecular gasses in a cold (10-13 K), starless core in the vicinity of Rossano cloud B (Corona Australis) which we have designated Object 42. We calculated and mapped C18O and N2H+ column densities and investigated the possibility of gas phase depletion in the core, which can occur as volatiles freeze out onto dust grains. This research is supported by Rensselaer Polytechnic Institute and the New York Center for Astrobiology which is a member of the NASA Astrobiology Institute. 129.12 New Interstellar Ammonia Maser Emission in NGC 7538: Expanded Very Large Array and Green Bank Telescope Observations Stella Seojin Kim1, I. M. Hoffman1 1St. Paul's School. 8:00 AM - 7:00 PM Essex Ballroom Using the Expanded Very Large Array and the Green Bank Telescope, we have observed the ammonia maser in NGC 7538 for the first time since its discovery in 1984. We present the first interferometric observations of the maser, demonstrating the nonthermal nature of the emission and providing a precise location for the maser in the star-forming complex. We also detect several new maser components that have appeared in the last 25 years. This maser is the nonmetastable (J,K) = (9,6) transition of ammonia at 18.5 GHz. We present a single epoch of observation with the EVLA in September 2010 and two epochs with the GBT in December 2010 and January 2011, with the following results: (1) We find several new emission peaks near -56 km/s in addition to the known emission near -60 km/s. All of the emission features have flux densities of approximately 1 Jy. (2) In GBT observing epochs separated by six weeks we do not find any of the maser features to vary in intensity. (3) In both the GBT and EVLA data, we resolve spectrally the emission feature near -60 km/s into two peaks and the emission features near -56 km/s into at least four peaks, all with widths of approximately 0.5 km/s. (4) At the three-arcsecond angular resolution of the EVLA observations, we find all of the maser features to be spatially coincident with each other on the sky and to lie at the location of the compact HII region IRS1. (5) The maser features are angularly unresolved in the EVLA images, indicating a lower limit of 500 K brightness temperatures. Given equivalent thermal line widths of 100 K, these brightness temperatures indicate nonthermal emission. This work is supported by the Thomas Penrose Bennett Prize Fund and the Lovejoy Science Fund of St. Paul's School. 129.13 Bound Cluster Formation in the Antennae Lisa H. Wei1, E. R. Keto1, L. C. Ho2 1Harvard-Smithsonian Center for Astrophysics, 2Carnegie Observatories. 8:00 AM - 7:00 PM Essex Ballroom Observations by the Hubble Space Telescope have revealed a wealth of super star clusters (SSCs) in lower extinction areas between dust lanes of starburst galaxies. These SSCs may be present-day analogues of young globular clusters, and are thought to form directly from giant molecular clouds. The mode of formation (efficient compression from shocks vs. slow compression within super giant molecular clouds), however, is still not well-understood. We report on high-spatial resolution CO(2-1) observations of the Antennae Galaxies with the Submillimeter Array (SMA) and the IRAM Plateau de Bure Interferometer (PdBI). We discuss the implications of our results on the various formation scenarios of SSCs in starburst galaxies. 129.14 Far-ultraviolet Observation Of The Aquila Rift With Fims Instrument Sung-Joon Park1, K. Min2, K. Seon1, W. Han1, D. Lee1, J. Edelstein3 1Korea Astronomy and Space Science Institute, Korea, Republic of, 2Korea Advanced Institute of Science and Technology, Korea, Republic of, 3Space Sciences Lab., University of California, Berkeley. 8:00 AM - 7:00 PM Essex Ballroom We present the first FUV observation of the Aquila Rift region near the Galactic plane by the FIMS instrument flown aboard the STSAT-1. Various wavelength datasets are used to compare with our FUV observation. While the core of the Aquila Rift suffers heavy dust extinction, the FUV continuum emission outside the Aquila Rift is found to be proportional to the certain amount of dust. The FUV Intensity clearly correlates with the dust extinction for E(B-V) < 0.3,, while anti-correlation is seen for E(B-V) > 0.3, which is in agreement with Hurwitz (1994) and Luhman & Jaffe (1996). Our entire field of view basically consists of inside and outside of Aquila Rift. The “Aquila-East,” “Aquila-Serpens,” and “Aquila-West,” are the inside sub-regions, and the “Scutum,” “Halo,” “Ophiuchus,” and “Hercules” are the outside. The CLOUD model and the calculation of H2 fluorescent line intensities are applied to investigate the physical conditions of each inside sub-region. Based on the velocity break (l ~ 33°) in CO emission and our result that the H2 fluorescent emission is poor in the “Aquila-East” region compared to the “Aquila-Serpens” and “Aquila-West” regions although the ``Aquila-East'' is similar to the other two inside sub-regions, we conclude the east region of Aquila is different in molecular condition or dust distribution, which may be related with the fact that the “Aquila-East” region is lack of star-forming regions. Furthermore, by calculating the line ratio of H2 fluorescent emissions, the characteristics of temperature and amount of dust can be expected for each sub-region. 129.15 Resolved Magnetic Field Map of GRSMC 45.60+0.30 Robert Marchwinski1, M. Pavel1, D. Clemens1, A. Pinnick1 1Boston University. 8:00 AM - 7:00 PM Essex Ballroom We present the first resolved magnetic field strength map for the quiescent molecular cloud GRSMC 45.60+0.30. GRSMC 45.60+0.30 subtends approximately 40 pc at a distance of 1.88 kpc. Polarization data were taken using the 1.8m Perkins telescope with the Mimir instrument. The data were processed using the custom IDL reduction pipeline for the GPIPS project, returning starlight polarization information in and around the cloud. Using the Chandrasekhar-Fermi method, the polarization angle dispersions were combined with the cloud radius, peak intensity, and velocity dispersion from the 13CO Galactic Ring Survey to create a resolved magnetic field map. An average magnetic field strength of approximately 4 microgauss was found across the cloud, with increases to around 13 microgauss in the 7 'magnetic cores.' This work was partially supported by NSF AST 09-07790. 129.16 PAHs in Translucent Interstellar Clouds Farid Salama1, G. Galazutdinov2, J. Krelowski3, L. Biennier4, Y. Beletsky5, I. Song6 1NASA Ames Research Center, Space Science & Astrobiology Division, 2Instituto de Astronomia, Universidad Catolica del Norte, Chile, 3Center for Astronomy, Nicolaus Copernicus University, Poland, 4Institut de Physique de Rennes, UMR 6251 du CNRS, France, 5European Southern Observatory, Chile, 6Korea Science Academy, Korea Advanced Institute of Science and Technology, Korea, Republic of. 8:00 AM - 7:00 PM Essex Ballroom We discuss the proposal of relating the origin of some of the diffuse interstellar bands (DIBs) to neutral polycyclic aromatic hydrocarbons (PAHs) present in translucent interstellar clouds. The spectra of several cold, isolated gas-phase PAHs have been measured in the laboratory under experimental conditions that mimic the interstellar conditions and are compared with an extensive set of astronomical spectra of reddened, early type stars. This comparison provides - for the first time - accurate upper limits for the abundances of specific PAH molecules along specific lines-of-sight. Something that is not attainable from IR observations alone. The comparison of these unique laboratory data with high resolution, high S/N ratio astronomical observations leads to two major findings: (1) a finding specific to the individual molecules that were probed in this study and, which leads to the clear and unambiguous conclusion that the abundance of these specific neutral PAHs must be very low in the individual translucent interstellar clouds that were probed in this survey (PAH features remain below the level of detection) and, (2) a general finding that neutral PAHs exhibit intrinsic band profiles that are similar to the profile of the narrow DIBs indicating that the carriers of the narrow DIBs must have close molecular structure and characteristics. This study is the first quantitative survey of neutral PAHs in the optical range and it opens the way for unambiguous quantitative searches of PAHs in a variety of interstellar and circumstellar environments. // Reference: F. Salama et al. (2011) ApJ. 728 (1), 154 // Acknowledgements: F.S. acknowledges the support of the NASA’s Space Mission Directorate APRA Program. J.K. acknowledges the financial support of the Polish State (grant N203 012 32/1550). The authors are deeply grateful to the ESO archive as well as to the ESO staff members for their active support. 129.17 Physical Processes in the Rosette Nebula Jeremy Michael Huber1, J. F. Kielkopf1 1University of Louisville. 8:00 AM - 7:00 PM Essex Ballroom The Rosette Nebula is an apparently spherical HII region which, though approximately 5000 light years distant, spans approximately 1.5 degrees of sky. Larger and much less luminous than the nearby Orion nebula, its faintness and angular size have made examination of the physical processes driving its shape, structure, and dynamics difficult. The spatial morphology of the nebula, which interacts with the associated Rosette Molecular Cloud complex, is obscured by the interstellar dust produced by previous generations of star formation. Our research seeks to construct a multispectral data set for the nebula and its environment, and through that to develop an observationally informed three dimensional model for the gas and dust densities, temperature, composition and motion. The distinctive ring of the Rosette is thought to be caused by radiation and winds from a central cluster of recently formed hot (OB) stars. The interaction of these stars with the nebula may be modeled based on physical first principles with CLOUDY and CLOUDY3D, thereby yielding a self-consistent understanding of the flow of energy from its stars and its appearance across the full spectrum from the ultraviolet to the radio. We are searching for evidence of prior episodes of star formation, and an understanding of the development of the heavy elements, molecules, and dust that are precursors to Earth-like planet formation. We have acquired narrow band images and long-slit spectra using wide-field instrumentation at Moore Observatory of the University of Louisville as the first phase of this project. Mosaics of the entire Rosette nebula with a 3.8 degree field of view and 4 arcsecond resolution have been produced in Hα, Hß, [OIII], and [SII]. Additionally, an initial characterization of the dust density of the region achieved through analysis of the Hα/Hß line ratio from these images is presented. 129.18 Discovery Of 6.035 GHz OH Maser Flares In IRAS 18566+0408 Esteban Araya1, A. A. Al Marzouk1, P. Hofner2, S. Kurtz3, H. Linz4, L. Olmi5 1Western Illinois University, 2New Mexico Tech, 3CRyA, Universidad Nacional Autonoma de Mexico, Mexico, 4MPIfA, Germany, 5University of Puerto Rico, and INAF. 8:00 AM - 7:00 PM Essex Ballroom We report the discovery of 6.035 GHz hydroxyl (OH) maser flares toward the massive young stellar object IRAS 18566+0408, which is the only region known to show periodic formaldehyde (4.8 GHz H2CO) and methanol (6.7 GHz CH3OH) maser flares. The observations were conducted between October 2008 and January 2010 with the 305m Arecibo Telescope in Puerto Rico. We detected two flare events, one in March 2009 and the other in September to November 2009. The 6.035 GHz OH flares are not simultaneous with the H2CO flares; the peak of the OH flares appears to be delayed by 1 to 3 months with respect to the formaldehyde flares. On the other hand, the OH flares occurred simultaneously with CH3OH flares from maser components that have approximately the same LSR velocity as the OH. The correlated variability of OH and CH3OH masers in IRAS 18566+0408 supports a common excitation mechanism (IR pumping) as predicted by theory. EA acknowledges support from the WIU OSP. PH acknowledges partial support from NSF grant AST-0908901. 129.19 Submillimeter and Far-Infrared Observations of the Carina Nebula Thomas E. Oberst1, S. C. Parshley2, T. Nikola2, G. J. Stacey2, A. Loehr3, A. P. Lane3, A. A. Stark3, J. Kamenetzky4 1Westminster College, 2Cornell University, 3Harvard-Smithsonian Center for Astrophysics, 4University of Colorado. 8:00 AM - 7:00 PM Essex Ballroom We present the results of a ~ 250 arcmin2 mapping of the 205 μm [NII] fine-structure emission over the northern Carina Nebula, including the Car I and Car II HII regions. Spectra were obtained using the South Pole Imaging Fabry-Perot Interferometer (SPIFI) at the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) at South Pole. We supplement the 205 μm data with new reductions of far-IR fine-structure spectra from the Infrared Space Observatory (ISO) in 63 μm [OI], 122 μm [NII], 146 μm [OI], and 158 μm [CII]. Morphological comparisons are made with optical, radio continuum and CO maps. The 122 [NII] / 205 [NII] line ratio is used to probe the density of the low-ionization gas, and the 158 [C II] / 205 [NII] line ratio is used to probe the fraction of C+ arising from photodissociation regions (PDRs). From the [OI] and [CII] data, we construct a PDR model of Carina following Kaufman et al. (1999). When the PDR properties are compared with other sources, Carina is found to be more akin to 30 Doradus than Galactic star-forming regions such as the Orion Bar, M17, or W49; this is consistent with the view of Carina as a more evolved region, where much of the parent molecular cloud has been ionized or swept away. These data constitute the first ever ground-based detection of the 205 μm [NII] line, and only the third detection overall since those of the COBE FIRAS and the KAO in the early 1990s. 129.20 H I Structure and Topology of the Galaxy Revealed by the I-GALFA H I 21-cm Line Survey Bon-Chul Koo1, G. Park1, W. Cho1, S. J. Gibson2, J. Kang3, K. A. Douglas3, J. E. G. Peek4, E. J. Korpela5, C. E. Heiles5 1Seoul National Univ., Korea, Republic of, 2Western Kentucky University, 3Arecibo Observatory, 4Columbia University, 5University of California. 8:00 AM - 7:00 PM Essex Ballroom The I-GALFA survey mapping all the H I in the inner Galactic disk visible to the Arecibo 305m telescope within 10 degrees of the Galactic plane (longitudes of 32 to 77 degrees at b = 0) completed observations in 2009 September and will soon be made publicly available. The high (3.4 arcmin) resolution and tremendous sensitivity of the survey offer a great opportunity to observe the fine details of H I both in the inner and in the far outer Galaxy. The reduced HI column density maps show that the HI structure is highly filamentary and clumpy, pervaded by shell-like structures, vertical filaments, and small clumps. By inspecting individual maps, we have found 36 shell candidates of angular sizes ranging from 0.4 to 12 degrees, half of which appear to be expanding. In order to characterize the filamentary/clumpy morphology of the HI structure, we have carried out statistical analyses of selected areas representing the spiral arms in the inner and outer Galaxy. Genus statistics that can distinguish the ``meatball'' and ``swiss-cheese'' topologies show that the HI topology is clump-like in most regions. The two-dimensional Fourier analysis further shows the HI structures are filamentary and mainly parallel to the plane in the outer Galaxy. We also examine the level-crossing statistics, the results of which are described in detail in an accompanying poster by Park et al. 129.21 Automatic Searching Algorithm For Galactic HI At Forbidden Velocities In The Inner-Galaxy ALFA Low-Latitude HI (I-GALFA) Survey Ji-hyun Kang1, B. Koo2, S. J. Gibson3, K. A. Douglas1, G. Park2, J. E. G. Peek4, E. J. Korpela5, C. E. Heiles6 1NAIC/Arecibo Observatory, 2Seoul National University, Korea, Republic of, 3Western Kentucky University, 4Columbia University, 5University of Exeter, United Kingdom, 6University of California - Berkeley. 8:00 AM - 7:00 PM Essex Ballroom The faint wing-like features at velocities beyond the velocity boundaries of the Galactic rotation (Forbidden-Velocity Wings, FVWs) in the large-scale position-velocity diagrams of the HI surveys are thought to be associated with dynamical Galactic events. The primary candidates of these FVWs are rapidly expanding HI shells of the old Galactic supernova remnants (SNRs), which are too faint to be visible in other frequencies. The unprecedented sensitivity and resolution of the I-GALFA survey enable detection of "all" HI shells of Galactic SNRs at forbidden velocities predicted by Koo and Kang (2004). Therefore, comparing the distribution of the FVWs visible in the I-GALFA survey and that of the model will improve our understanding on the interstellar medium and the evolution of SNRs. We have been developing an automatic searching algorithm for FVWs in the I-GALFA survey to minimize the selection effects of visual inspection used in the previous FVW study. We present the searching mechanism for FVWs and the statistical properties of the automatically searched FVWs. Also, we discuss the similarities and the differences between the distribution of the identified FVWs and that of the SNRs predicted by Koo and Kang (2004). 129.22 Through The Looking Glass: New Laboratory Spectra Of Glassy Silicates For The Comparison To Astrophysical Environments Angela Speck1, A. Whittington1, A. Hofmeister2 1Univ. of Missouri, 2Washington University. 8:00 AM - 7:00 PM Essex Ballroom Many astrophysical environments exhibit a spectral feature at around 10 microns, which has long been attributed to amorphous silicates, but whose precise nature remains a mystery. Furthermore, the astronomically observed feature varies from location to location, and even within a given object both spatially and temporally. There have been many laboratory studies of potential cosmic dust analogs attempting to determine the exact nature of this dust, but most of those studies have failed to produce laboratory spectra that precisely match the observed astronomical spectra. We present new high-resolution spectra of a selection of silicate glasses whose compositions cover those expected to form in cosmic environments. These include synthetic endmember glasses of major mineral groups such as melilites (akermanite, gehlenite), pyroxenes (enstatite), olivines (forsterite) and silica; glasses produced by remelting natural mineral samples that contain iron and other elements; and a synthetic “cosmic” silicate glass with solar relative abundances of Mg, Si, Ca, Na and Al. Across the compositional range of 12 samples the 10 micron feature changes in peak position by more than a micron, as well as in shape. We discuss the effects of both compositional and structural factors on spectral features in these glassy silicates and we compare our new laboratory glass spectra with synthetic amorphous silicate spectra currently used in most models of dusty astrophysical environments. The synthetic spectra do not match either peak position or shape of any of our glass samples. 129.23 Sulfur in the Interstellar Medium Betsy White1, U. J. Sofia1 1American University. 8:00 AM - 7:00 PM Essex Ballroom Sulfur is abundant in the interstellar medium and its presence in grains could have important implications for extinction, yet little analysis has been done to measure the abundance of sulfur in grains. Previous abundance studies have suggested that sulfur does not contribute significantly to interstellar dust. However, studies of dust in meteorites indicate that sulfur is present in dust. We analyzed the strong S\sc{ii} 1250, 1253, 1259 \AA\ features in high-resolution STIS data to expand the sample of interstellar sulfur determinations. We present the interstellar abundance measurements of 28 sight lines for singly ionized sulfur atoms, the dominant form of sulfur in the interstellar medium. Our preliminary results indicate that sulfur is depleted into grains but does not follow the pattern of other elements in dust. 129.24 Ultraviolet Photometry of Dust Extinction in M101: Expected Results from the IMAGER Sounding Rocket Meredith E. Danowski1, T. A. Cook1, K. D. Gordon2, S. Chakrabarti1 1Boston University, 2Space Telescope Science Institute. 8:00 AM - 7:00 PM Essex Ballroom Scheduled for launch in summer 2011, the Interstellar Medium Absorption Gradient Experiment Rocket (IMAGER) will probe the correlation between ultraviolet dust extinction, and the metallicity and radiation environment in M101. IMAGER simultaneously images M101 in four 400Å-wide bandpasses, targeting UV extinction features. We present technical results from telescope and instrument calibration and integration, as well as expected science results from the unique IMAGER design. With nearly face-on orientation, large angular extent, a steep metallicity gradient, and many well-studied HII regions, M101 is an ideal laboratory for the study of dust near regions of massive star formation. Evidence from studies of starburst galaxies indicates that active, high mass star formation modifies the UV dust extinction curve, demonstrated by the lack of a characteristic 2175Å bump. With ultraviolet photometry from IMAGER, we measure the apparent strength of the 2175Å bump, the far-UV rise, and the UV continuum. IMAGER observations, infrared data from Spitzer, the DIRTY radiative transfer model, and stellar evolution models allow us to examine the morphology in the UV extinction curve and the IR emission features as a function of metallicity and radiation field hardness. This study will directly impact our understanding of the nature of dust and our ability to accurately account for the effects of dust on observations at all redshifts. 129.25 Emission from Interstellar Dust in the Heliosphere Jonathan David Slavin1, P. C. Frisch2, W. T. Reach3, J. Heerikhuisen4, N. V. Pogorelov4, H. R. Mueller5, G. P. Zank4 1Harvard-Smithsonian, CfA, 2University of Chicago, 3USRA/SOFIA, 4CSPAR/University of Alabama, 5Dartmouth College. 8:00 AM - 7:00 PM Essex Ballroom Interstellar dust (ISD) has been directly observed flowing into the Solar System. This dust has an unusual size distribution relative to typical ISD with small grains (a < 0.1 micron) deficient and large grains (about 1 micron) abundant. Such large grains are not expected to be present in warm, low density gas such as the Local Interstellar Cloud (LIC) that surrounds the Solar System. It is unclear whether the missing small grains have been excluded from the inner heliosphere by the solar wind magnetic field, or whether they are absent entirely from the LIC. If the grains are present in the LIC their density should be enhanced in the heliosheath and they should be heated by the Sun's UV radiation field. The emission from such grains may be observable and would provide a means of observing the grains that is lacking otherwise. We present the results of new models for the emission of the grains based on calculations of the trajectories of ISD grains incident on the heliosphere and resulting space densities as a function of grain size. 130 Galactic & Extra-Galactic Star Formation Poster Session Essex Ballroom 130.01 Spatially Resolved Molecular Gas Star Formation Law in CARMA Survey Towards Infrared-bright Nearby Galaxies (STING) Nurur Rahman1, A. Bolatto1, STING collaboration 1University of Maryland. 8:00 AM - 7:00 PM Essex Ballroom The STING is a CARMA 3mm survey of nearby galaxies. We will present a comprehensive analysis of the relationship between the star formation rate surface density and molecular gas surface at the sub-kpc level in the STING sample. To construct the tracers of molecular gas and star formation rate surface densities, respectively, we will use high resolution (3-5") CO (J=1-0) data from CARMA and the mid-infrared 24 micron data of comparable resolution (6") from Spitzer Space Telescope. We measure the relation in the bright region of these galaxies. In our preliminary analysis we find an approximately linear relation and no strong trends for either the logarithmic slope or the molecular depletion time across the range of galaxy masses sampled (10^9-10^11.5 Msun). 130.02 Star Formation Rates in Galaxy Groups in COSMOS Stephanie Fiorenza1 1CUNY Graduate Center. 8:00 AM - 7:00 PM Essex Ballroom This study examines the star formation rates within a sample of groups selected from the Cosmic Evolution Survey (COSMOS), a 2 deg2 multi-wavelength imaging and spectroscopic survey from x-ray to radio wavelengths. Of the roughly 1,000,000 objects within the COSMOS survey, ~20,000 currently have secure spectroscopic redshifts. The sample of galaxy groups is selected from x-ray data and has been spectroscopically confirmed. The sample encompasses more than 100 galaxy groups with a mass range of 1013 - 1015 solar masses and a redshift range of 0.1 ≥ z ≥ 1. Stellar mass fraction has previously been found to be anti-correlated with total mass, with clusters having lower stellar mass fractions than groups, while gas mass has been found to be positively correlated with total system mass. I investigate if star formation is a process that could significantly account for these and other observed properties of galaxy groups and the intra-group medium. Assuming representative initial-mass functions, I measure the total and specific star formation rates in the group galaxies. These results can be further applied to determine if the feedback from star formation can account for the observed baryon deficit observed within intra-group media, perhaps by blowing the baryonic interstellar gas out of the groups. 130.03 The Star Formation Reference Survey -- Survey Design and Basic Data Matthew Ashby1, S. Mahajan1, H. A. Smith1, S. Willner1, G. G. Fazio1, S. Raychaudhury2, A. Zezas3, P. Barmby4, P. Bonfini3, C. Cao5, E. Gonzalez-Alfonso6, D. Ishihara7, H. Kaneda7, V. Lyttle4, S. Madden8, C. Papovich9, E. Sturm10, J. Surace11, H. Wu12, Y. Zhu12 1SAO, 2University of Birmingham, United Kingdom, 3University of Crete, Greece, 4University of Western Ontario, Canada, 5Shandong University at Weihai, China, 6University de Alcala de Henares, Spain, 7Nagoya University, Japan, 8CEA/Saclay, France, 9Texas A & M University, 10MPE, Germany, 11Spitzer Science Center, 12National Astronomical Observatories, China. 8:00 AM - 7:00 PM Essex Ballroom We report on the survey design, available data, and first outcomes from the Star Formation Reference Survey, a program designed to systematically elucidate the properties of star forming galaxies. By controlling for both total and specific star formation rate together with dust temperature, we have assembled a large infrared-selected galaxy sample that is fully representative of all conditions under which star formation occurs in the local Universe. A rich dataset spanning multiple bands from the UV to the mid-IR and into the radio is now being used to assess the reliabilty and systematics of the star formation rate indicators commonly used in the literature, with an eye toward establishing a firmer baseline for the interpretation of faint, distant sources from deep infrared surveys. This work was supported by NASA grant number 1256790, administered by JPL. 130.04 Young Stellar Populations in the W3 Star-Forming Region Megan Bagley1, J. Jose2, J. S. Kim1, M. Bagley1, M. R. Meyer3, W. Sherry4, V. Roccatagliata5, L. Townsley6, E. Feigelson6 1University of Arizona, 2ARIES, India, 3ETH, Switzerland, 4NOAO/NSO, 5STScI, 6Pennsylvania State University. 8:00 AM - 7:00 PM Essex Ballroom We present recent results and updates from our multi-wavelength imaging and spectroscopic studies of young stars in the W3 star-forming complex and the surrounding area including IC 1795, W3 North, W3(OH), W3 Main, W3 South, and AFGL 333. We introduce newly-found embedded clusters and aggregates in W3 South and AFGL 333. The W3/W4/W5 complexes are well-known sites of massive star formation and are ideal sites to study the triggered mode of star formation. We conducted a systematic imaging and spectroscopic survey to study the initial mass function and the evolution of circumstellar disks in such an environment. We obtained optical imaging data and spectra with the 90 Prime on the Bok telescope and the Hectospec on the MMT, respectively, and we also made use of archival infrared data from 2MASS and Spitzer and X-ray data from Chandra. We present spectroscopically confirmed young stars and discuss their stellar properties. Using improved determinations of stellar ages and masses, we analyse the circumstellar disk frequency and the disk properties of young stars for M > ~0.8 Msun. 130.05 On the Initial Conditions for Star Formation and the IMF Bruce Elmegreen1 1IBM Research Div.. 8:00 AM - 7:00 PM Essex Ballroom Density probability distribution functions (PDFs) for turbulent self-gravitating clouds should be convolutions of the local log-normal PDF, which depends on the local average density rho-ave and Mach number M, and the probability distribution functions for rho-ave and M, which depend on the overall cloud structure. When self-gravity drives a cloud to increased central density, the total PDF develops an extended tail. If there is a critical density or column density for star formation, then the fraction of the local mass exceeding this threshold becomes higher near the cloud center. These elements of cloud structure should be in place before significant star formation begins. Then the efficiency is high so that bound clusters form rapidly, and the stellar initial mass function (IMF) has an imprint in the gas before destructive radiation from young stars can erase it. The IMF could arise from a power-law distribution of mass for cloud structure. These structures should form stars down to the thermal Jeans mass MJ at each density in excess of a threshold. The high-density tail of the PDF, combined with additional fragmentation in each star-forming core, extends the IMF into the Brown Dwarf regime. The core fragmentation process is distinct from the cloud structuring process and introduces an independent core fragmentation mass function (CFMF). The CFMF would show up primarily below the IMF peak. 130.06 A Search for Triggered Star Formation William Joseph Dirienzo1, R. Indebetouw2, C. Brogan3 1University of Virginia, 2University of Virginia/National Radio Astronomy Observatory, 3National Radio Astronomy Observatory. 8:00 AM - 7:00 PM Essex Ballroom A study was conducted to search for evidence of triggered star formation in six galactic H II regions with suggestive “bubble” morphology in a range of apparent evolutionary states. Young Stellar Objects (YSOs) in these regions were identified from the GLIMPSE point source catalog. Photometric data covering 1.25 μm to 24 μm wavelengths with the 2MASS survey and the Spitzer Space Telescope GLIMPSE and MIPSGAL surveys (utilizing the IRAC and MIPS instruments, respectively) was obtained for each source. The identification was performed by fitting the spectral energy distributions of each source with a collection of previously published YSO radiative transfer models. This method allows for an estimate of each YSO’s physical characteristics from the parameters of the models, including mass, luminosity, evolutionary stage, and age. The physical environments were analyzed using CO data from the Boston University Galactic Ring Survey and radio continuum data from the VLA Galactic Plane Survey and the Nobeyama 3 cm Survey. The ages of the H II regions are estimated from the physical characteristics of the region. Finally, the spatial distribution of YSOs and the timescales of YSO formation and H II region expansion are assessed for consistency or discrepancy with the collect and collapse and radiatively driven implosion models of triggered star formation. This work is based [in part] on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech. 130.07 Interactions Between Forming Stars and Dense Gas in a Small Low Mass Cluster Edwin F. Ladd1, T. Wong2, T. L. Bourke3, K. L. Thompson4 1Bucknell Univ., 2University of Illinois, 3Harvard-Smithsonian Center for Astrophysics, 4University of Kentucky. 8:00 AM - 7:00 PM Essex Ballroom We present observations of dense gas and outflow activity in the Cederblad 110 region of the Chamaleleon I Dark Cloud. The region contains eight forming low mass stars in evolutionary stages ranging from Class 0 to Class II/III crowded into a 0.2 pc region with high surface density (Σ_YSO ~150 pc^-2). The analysis of our N2H+ (J=1-0) maps indicates the presence of 15 solar masses of dense (n ~10^5 cm^-3) gas in this region, much of which is unstable against gravitational collapse. The most unstable material is located near the Class 0 source MMS 1. Smaller column densities of more stable dense gas are found toward the region's Class I sources. Little or no dense gas is colocated with the Class II and III sources in the region. The outflow from the Class I source IRS 4 is interacting with the dense core associated with MMS 1. The molecular component of the outflow appears to be deflected by the densest part of the core, after which it plows through some of the lower column density portions of the core. The working surface at the head of the outflow lobe can be seen in the enhanced velocity dispersion of the dense gas. The Class III source IRS 2 may also be influencing the dense gas in the region. A dust temperature gradient across the core is consistent with warming from the 3.4 Lo source, and a sharp gradient in dense gas column density may be caused by winds from this source. Taken together, our data indicate that this region has been producing several young stars in the recent past, and that sources which began forming first are interacting with the remaining dense gas in the region, thereby influencing current and future star formation activity. 130.08 New Data for Five New Orion PMS Eclipsing Binaries from the Spitzer YSOVAR Program. Maria Morales-Calderon1, J. R. Stauffer1, L. Prato2, L. A. Hillenbrand1, D. Terndrup3, S. Terebey4, L. M. Rebull1, K. Stassun5, A. Boden6 1CALTECH, 2Lowell Observatory, 3Ohio State University, 4California State University at Los Angeles, 5Vanderbilt University, 6Palomar Observatory - CALTECH. 8:00 AM - 7:00 PM Essex Ballroom In Fall 2009, we conducted a large, multi-wavelength time-series photometric monitoring campaign of about a one square degree region of the Orion Nebula cluster (ONC). From these data we identify nine stars in our field of view whose light curves show eclipse features. Four of these are the previously known ONC eclipsing binaries (EBs) and the other five systems are newly identified ONC PMS EB candidates - more than doubling what was known up to now. Here we present our follow-up observations and current work to confirm these candidates. 130.09 Cluster Evolution In The Rosette Molecular Cloud Main Core Region Jason E. Ybarra1, C. Román-Zúñiga2, E. A. Lada1, Z. Balog3 1Univ. of Florida, 2Universidad Nacional Autónoma de México, Mexico, 3Max-Planck-Institut für Astronomie, Germany. 8:00 AM - 7:00 PM Essex Ballroom Using Spitzer Space Telescope and Chandra X-ray data, we identify YSOs in the RMC main core region. Nearest Neighbor Method (NNM) was employed to analyze the structures and distributions of Class I/0, Class II, and Class III sources. Additionally, we developed a ratio mapping technique to investigate the progression of star formation. We discuss the distribution of YSOs, progression of star formation, and structure of the clusters in this region. This work is based in part on archival data obtained with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by an award issued by JPL/Caltech, Florida Space Grant Consortium, and a NASA GSRP fellowship. 130.10 Outflows, Hot-core And Magnetic Fields In G30.79fir10 Tirupati K. Sridharan1 1Harvard-Smithsonian CfA. 8:00 AM - 7:00 PM Essex Ballroom We present spectral line and dust polarization observations of G30.79FIR10 also known as W43-mm1, the brightest dust emission core in W43. The data were obtained with the Submillimeter Array (SMA) at ~ 345 GHz. Massive, jet-like outflows are observed in CO. A remarkable hot core with CH3CN (J=19-18) emission detected up to K = 10 and a temperature of ~ 300K is revealed. The magnetic field implied by the polarized dust emission is discussed. 130.11 Classifying Star Forming Cores through Chemical Anomalies Sadia Hoq1, J. Jackson1, J. Foster1 1Boston University. 8:00 AM - 7:00 PM Essex Ballroom The chemical makeup of Infrared Dark Clouds may offer a method to classify star forming cores. This study uses the molecular line maps from the Millimetre Astronomy Legacy Team 90 GHz (MALT90) Survey, observed using the 22-m ATNF Mopra Telescope. The relative abundances of the four molecules, N2H+, HNC, HCN and HCO+ are calculated for each of 500 cores to determine the chemical signatures of star forming cores in their early evolutionary stages, as deduced from Spitzer data. Cores are classified as prestellar, protostellar, or HII regions. Initial findings indicate that sources with relatively strong N2H+ lines are prestellar, whereas weak N2H+ lines may designate protostellar or HII regions. These chemical anomalies, where the N2H+ lines are either very prominent or weak are rare, suggesting that these are short-lived chemical phases. 130.12 Wide-field, High-resolution, Millimeter-wavelength Spectral Imaging Of The Serpens Core Stuartt A. Corder1, H. G. Arce2 1National Radio Astronomy Observatory, 2Yale University. 8:00 AM - 7:00 PM Essex Ballroom We present combined CARMA and FCRAO 12CO(1-0), 13CO(1-0), and C18O(1-0) emission line maps of the Serpens Core as well as 2.7 mm continuum images from CARMA alone. The maps sample spatial scales from 5" up to 10' (2000 AU to >1 pc). The Serpens Core is a dynamic, active star-forming region. Several remarkable features are revealed in the combined maps including outflows, shells, remnant cavities from outflows, and filaments. The continuum maps are remarkably sparse despite the presence of extended, dense gas as traced by the C18O emission. We are in the process of cataloging the energy injecting sources. In later analysis we will determine the power spectra of velocity and density fluctuations in the field to compare to models of star formation as well as determine the influence of these energetic source on the surrounding medium. The CARMA maps are part of a three-region survey of large (75-150 pointing) mosaics that includes Perseus B1 and NGC 1333. 130.13 Chemistry in Infrared Dark Cloud Clumps: a Molecular Line Survey at 3 mm Patricio Sanhueza1, J. M. Jackson1, J. B. Foster1 1Boston University. 8:00 AM - 7:00 PM Essex Ballroom We have observed 37 Infrared Dark Clouds (IRDCs) containing a total of 159 clumps with the 22-meter ATNF Mopra Telescope in Australia using high-density molecular tracers at 3 mm. We carried out single-pointing observations in the broad-band mode and detected 10 different molecular lines. The detections rates are dominated by HNC (1-0) (98%), N2H+ (1-0) (97%), and HCO+ (1-0) (88%) lines, showing similar values when we divide the sample into active and quiescent clumps (based on Spitzer IRAC and MIPS emission). However, we find differences of ~30% in the detection rates for the H13CO+, HN13C, and HC3N lines. We also find that the N2H+ FWHMs of active clumps are broader than those of quiescent clumps, possibly due to ongoing star formation activity driving turbulence. Integrated intensity and abundance ratios of some molecular lines vary between quiescent and active clumps tracing chemical differences which arise from different evolutionary states. 130.14 30 Dorados & the Sinusoidal Potential David F. Bartlett1, J. P. Cumalat1 1Univ. of Colorado. 8:00 AM - 7:00 PM Essex Ballroom The sinusoidal potential is an alternative to the Newtonian potential. In this alternative, the potential of a point mass is φ= -(GM/r) Cos[kor], where ko = 2π/ λo and λo is determined empirically to be Ro/20, Ro=8 kpc. A parallel modification to electromagnetism has also been suggested φ=-(Q/r) Exp -[kor] (Bartlett 2004). Recently an equivalent absolute value for ko has been posited: ko2= πG (α 2 me) 4 c/ (h-bar)3. The sinusoidal potential has been developed in presentations at many recent meetings of the AAS & the DDA. Generally, short-range structure (galaxies and smaller) are dominated by gravitation; long-range (clusters of galaxies and larger) by electromagnetism. 30 Dorados is still a puzzle. Why should this region of intense star formation be between the Large Magellanic Cloud and the Milky Way, but much closer to the former than the latter. Why should its size be roughly 400 pc? What is its connection to the Magellanic Stream? The sinusoidal potential may help. 131 Computation, Data Handling, Image Analysis Poster Session America Ballroom Foyer 131.01 Detecting Cosmic Rays in Infrared Data Rachel E. Anderson1, K. D. Gordon1 1STScI. 8:00 AM - 7:00 PM America Ballroom Foyer Cosmic rays are a known problem in infrared astronomy, causing both loss of data and data accuracy. The problem becomes even more extreme when considering data from a high radiation environment such as in orbit around Earth, or outside the Earth’s magnetic field altogether, unprotected, as is the case for the James Webb Space Telescope. To find the best method to correct for this disturbance we study three cosmic ray detection methods: a 2-point difference method, a deviation from the fit method, and a y-intercept method. These methods are applied to simulated non-destructive read ramps with various slopes, number of frames, number of cosmic rays, and cosmic ray frame number and strength. We show that the 2-point difference method is the fastest, optimal detection method in the photon-dominated regime and the y-intercept method is the optimal detection method in the read noise-dominated regime. 131.02 Full-text Indexing Of All Springer Astronomy And Physics Journals In The ADS Guenther Eichhorn1, H. Blom1, A. Accomazzi2 1Springer, 2Smithsonian Astrophysical Observatory. 8:00 AM - 7:00 PM America Ballroom Foyer Springer, as a publisher of scientific and technical literature, has been collaborating with the ADS since the very beginning of the ADS Abstract Service. Once of the culminations of this collaboration was the scanning of all back issues of Solar Physics. We are now in the process of enabling full text searching of all Springer journals in Astronomy and Physics through the ADS. This agreement between Springer and the ADS will be based on a similar agreement between Springer and INSPIRE. That agreement allows full text searching of Springer High Energy Physics journals in SPIRES and its successor INSPIRE, a database of the High Energy Physics literature developed and managed by a collaboration between CERN, DESY, Fermilab, and SLAC. Springer will provide the full text of all the Astronomy and Physics journals to the ADS for indexing. Display of search results will include snippets of text that includes the search terms, to allow the user to immediately see the context of the searched terms in the articles. Such a full text search will allow greatly enhanced search functionality and should allow much more detailed and in-depth searches of the relevant literature at Springer, one of the largest publishers of scientific-technical literature. We are currently in the process to determine whether this full text search capability can be extended to scientific books as well. 131.03 Exploring Sound to Convey Information Wanda Liz Diaz-Merced1, M. Schneps2, N. Brickhouse3, M. Pomplun4, S. Brewster1, J. Mannone1 1University of Glasgow, United Kingdom, 2Smithsonian Center for Astrophysics Science Media Group, 3Smithsonian Center for Astrophysics, 4University of Massachusetts. 8:00 AM - 7:00 PM America Ballroom Foyer In this poster we present sonification (the use of sound to convey information) techniques with an example applied to X-ray astronomy. We also present preliminary results of perception experiments. Using sonification we have identified frequencies in the Chandra X-Ray observations of EX Hya, a cataclysmic variable of the intermediate polar type. The frequencies corresponding to 2.44 and 28.3 mHz may be quasi-periodic oscillations characteristic of the source while those identified at 126, 258 and 386 mHz appear to be an instrumental effect. We have conducted perception experiments on 13 participants exposed to visual stimuli, auditory stimuli and visual and auditory stimuli together. The subjects were asked to identify signals in the presence of noise. They showed performance improvement when auditory stimuli were added to a visual display. The difference in performance between "sound only" and "visual graph only" is about 20 times larger. This may support the use of sound as an adjunct to data visualization in astronomy data analysis, especially when proper training is given to the users. The authors acknowledge the Smithsonian Institution Women Committee for sponsoring this research. 131.04 The Indra Simulation Database Bridget Falck1, T. Budavari1, S. Cole2, D. Crankshaw1, L. Dobos3, G. Lemson4, M. Neyrinck1, A. Szalay1, J. Wang2 1Johns Hopkins University, 2University of Durham, United Kingdom, 3Eotvos Lorand University, Hungary, 4Max-Planck Institute for Astrophysics, Germany. 8:00 AM - 7:00 PM America Ballroom Foyer We present the Indra suite of cosmological N-body simulations and the design of its companion database. Indra consists of 512 different instances of a 1 Gpc/h-sided box, each with 100 million dark matter particles and the same input cosmology, enabling a characterization of very large-scale modes of the matter power spectrum with galaxy-scale mass resolution and an excellent handle on cosmic variance. Each simulation outputs 64 snapshots, giving over 100 TB of data for the full set of simulations, all of which will be loaded into a SQL database. We discuss the database design for the particle data, consisting of the positions and velocities of each particle; the FOF halos, with links to the particle data so that halo properties can be calculated within the database; and the density field on a power-of-two grid, which can be easily linked to each particle’s Peano-Hilbert index. Initial performance tests and example queries will be given. The authors are grateful for support from the Gordon and Betty Moore and the W.M. Keck Foundations. 131.05 Introducing ADS Labs Alberto Accomazzi1, E. Henneken1, C. S. Grant1, M. J. Kurtz1, G. Di Milia1, J. Luker1, D. M. Thompson1, E. Bohlen1, S. S. Murray1 1Harvard Smithsonian Center for Astrophysics. 8:00 AM - 7:00 PM America Ballroom Foyer ADS Labs is a platform that ADS is introducing in order to test and receive feedback from the community on new technologies and prototype services. Currently, ADS Labs features a new interface for abstract searches, faceted filtering of results, visualization of co-authorship networks, article-level recommendations, and a full-text search service. The streamlined abstract search interface provides a simple, one-box search with options for ranking results based on a paper relevancy, freshness, number of citations, and downloads. In addition, it provides advanced rankings based on collaborative filtering techniques. The faceted filtering interface allows users to narrow search results based on a particular property or set of properties (“facets”), allowing users to manage large lists and explore the relationship between them. For any set or sub-set of records, the co-authorship network can be visualized in an interactive way, offering a view of the distribution of contributors and their inter-relationships. This provides an immediate way to detect groups and collaborations involved in a particular research field. For a majority of papers in Astronomy, our new interface will provide a list of related articles of potential interest. The recommendations are based on a number of factors, including text similarity, citations, and co-readership information. The new full-text search interface allows users to find all instances of particular words or phrases in the body of the articles in our full-text archive. This includes all of the scanned literature in ADS as well as a select portion of the current astronomical literature, including ApJ, ApJS, AJ, MNRAS, PASP, A&A, and soon additional content from Springer journals. Fulltext search results include a list of the matching papers as well as a list of “snippets” of text highlighting the context in which the search terms were found. ADS Labs is available at http://adslabs.org. 132 Instrumentation: Ground Based or Airborne Poster Session America Ballroom Foyer 132.01 Supernova Photometry with the LCOGT Faulkes Telescopes Benjamin E. Dilday1, D. Howell1, N. Brunner1, F. Bianco1, M. Graham1, LCOGT 1LCOGT. 8:00 AM - 7:00 PM America Ballroom Foyer Las Cumbres Observatory Global Telescope (LCOGT) is currently designing, constructing, and deploying a network of robotic telescopes which will consist of multiple 1m and 0.4m telescopes, positioned at sites distributed roughly equi-longitudinally around the globe. When completed, the network will enable unique opportunities for time-domain astronomy. The LCOGT network also includes the 2m Faulkes Telescopes (FTs); Faulkes North (Haleakala, Maui) and Faulkes South (Siding Springs, Australia). As a precursor to the full telescope network, LCOGT is operating the Faulkes Telescopes in a robotic observing mode, and one primary use of the FTs over the last two years has been to provide multi-color photometric follow-up of supernovae (SNe) discovered by the Palomar Transient Factory (PTF). We discuss the current status of FT photometry for SNe from PTF, including the photometric reduction pipeline, data-quality statistics, and photometric calibrations. 132.02 LCOGT Imaging Capabilities Timothy M. Brown1, B. Burleson1, J. De Vera1, M. Dubberley1, B. Haldeman1, E. Hawkins1, R. Haynes1, A. Hjelstrom1, J. Hygelund1, T. Lister1, R. Lobdill1, A. Pickles1, W. Rosing1, J. Tufts1 1LCOGT. 8:00 AM - 7:00 PM America Ballroom Foyer Las Cumbres Observatory Global Telescope (LCOGT) is developing a world-wide network of optical telescopes dedicated to time-domain astronomy. In a few years, the network will consist of more than twenty 0.4m telescopes, about fifteen 1m telescopes, and two 2m telescopes, all of which will initially be equipped for both high-speed and traditional CCD imaging. Instruments for high-speed applications are described in Bianco et al. (this session). Here we describe LCOGT's instruments for relatively wide-field imaging at moderate time cadence. The most notable of these is the "Sinistro" camera system being built for the 1m network. It consists of corrector optics, filter changer, photometric shutter, 16 Mpix CCD camera, and custom CCD controller. Each Sinistro component is optimized for precision photometric measurements, and the system provides a large critically sampled field to the full CCD, rapid access to as many as 21 different filters, minimized shutter overhead, flexible high-speed readout, support for multiple independent regions of interest, the ability to autoguide independently of camera focus, precision CCD temperature control and telemetry, and a dry nitrogen filter environment. 132.03 Floyds: A Robotic Spectrograph for the Faulkes Telescopes David J. Sand1, T. Brown1, R. Haynes1, M. Dubberley1 1UCSB/LCOGT. 8:00 AM - 7:00 PM America Ballroom Foyer Here we will present the Folded Low Order whYte-pupil Double-dispersed Spectrograph (FLOYDS), a low dispersion robotic spectrograph being built at Las Cumbres Observatory Global Telescope (LCOGT) Network for deployment at the Faulkes Telescopes. FLOYDS will be fully integrated into the LCOGT network, and will thus be able to robotically acquire targets and place them in the slit for science exposures. The principal scientific goals of FLOYDS include supernova classification and analysis, along with long duration spectroscopic monitoring of other variable sources, such as active galactic nuclei. We will discuss the design and operation expectations of FLOYDS, along with a progress report on its construction in the lab. In the era of large time domain surveys, robotic spectroscopy will play a critical role. 132.04 LIHSP: Lucky Imaging And High Speed Photometry at LCOGT Federica Bianco1, R. Street2, Y. Tsapras3, A. Shporer1, J. Tufts2, T. Lister2, E. Gomez4, W. Rosing2, T. Brown1, LCOGT team 1LCOGT-UCSB, 2LCOGT, 3LCOGT-Queen Mary University of London, United Kingdom, 4LCOGT-Cardiff University, United Kingdom. 8:00 AM - 7:00 PM America Ballroom Foyer Las Cumbres Observatory Global Telescope Network (LCOGT) is building a world wide telescope network with an emphasis on time domain astronomy. The final LCOGT network will have at least 40 telescopes in at least 7 sites around the world to continuously cover the dark sky in both hemispheres: two 2.0m telescopes, already available on Haleakala - HI, USA (FTN), and Siding Spring - Australia (FTS), roughly fifteen 1m, and twenty-five 0.4m telescopes now in various stages of construction and commissioning. We are integrating our telescopes with high speed EMCCD cameras to provide high speed photometry as well as lucky imaging capabilities. Here we present our first generation high speed solutions, already installed at FTN and FTS and currently being integrated into our robotic system. Similar facilities are being fabricated for the 0.4m network, and designed for the 1m network. 132.05 MWA Observations of Candidate EoR Fields Christopher L. Williams1, J. N. Hewitt1, MWA collaboration 1MIT. 8:00 AM - 7:00 PM America Ballroom Foyer The Murchison Widefield Array (MWA) is a new low-frequency, wide field-of-view radio array under construction in Western Australia, with a goal of detecting and characterizing radio emission from the epoch of reionization (EoR). A 32-element prototype interferometer has been deployed at the MWA site, and is currently being used for system characterization and early astronomical observations. Using this prototype array, we have observed candidate fields for our EoR detection experiment. We use these data to characterize the low-frequency radio point source population and discuss the implications of the properties of these fields for measuring the reionization power spectrum. 132.06 The Murchison Widefield Array (MWA): Exploring the Epoch of Reionization with the Redshifted 21 cm Line Judd D. Bowman1, M. F. Morales2, J. N. Hewitt3, MWA Collaboration 1Arizona State University, 2University of Washington, 3Massachusetts Institute of Technology. 8:00 AM - 7:00 PM America Ballroom Foyer The 21 cm hyperfine transition line of neutral hydrogen should provide a direct probe of the Epoch of Reionization (EoR). Detecting redshifted 21 cm emission from neutral gas in the intergalactic medium (IGM) during the EoR is the primary science goal of the Murchsion Widefield Array (MWA). When completed, the MWA will be sensitive primarily to the power spectrum of spatial fluctuations in the 21 cm background between redshifts 6 < z < 12. Its observations should characterize the properties of the sources that are responsible for ionizing the IGM, chart the evolution of the global neutral fraction, and probe the nature of quasar emissions by constraining the properties of their ionized proximity zones. Foreground subtraction is a critical challenge for redshifted 21 cm measurements. Developing the resources to successfully extract the 21 cm signal from Galactic and extragalactic foregrounds is a crucial objective for the MWA. We describe the foreground-removal techniques that are planned for use with the MWA, the metrics against which the success of foreground removal will be evaluated, and the requirements on overall array performance and calibration imposed by the EoR science goals. 132.07 The Murchison Widefield Array (MWA): Current Status and Plans Alan Whitney1, T. Booler2, J. Bowman3, D. Emrich2, B. Goeke4, R. Remillard4 1MIT Haystack Observatory, 2Curtin University, Australia, 3Arizona State University, 4MIT. 8:00 AM - 7:00 PM America Ballroom Foyer The Murchison Widefield Array (MWA) is a low frequency radio telescope of novel design, being built in the sparsely populated outback of western Australia, by a consortium of US, Australian and Indian institutions. The pristine environment for radio frequency interference facilitates sensitive measurements in support of science goals ranging from cosmology to space weather. The array operates in the 80-300 MHz range, and comprises 512 antenna "tiles" scattered over a ~3km diameter region, each composed of 16 dual-polarization broadband dipoles. The received signals are digitized in the field, and transported by optical fiber to a central processing facility for correlation. The design and hardware components will be described, and the current state of construction will be summarized. The plans for completion of construction, test and verification of the hardware, commissioning of the array, and science operations will be presented. 132.08 The Murchison Widefield Array (MWA) and the Path to HERA Colin J. Lonsdale1, J. Bowman2, J. Hewitt3, M. Morales4, J. Moran5 1MIT Haystack Observatory, 2Arizona State University, 3MIT, 4University of Washington, 5Harvard Smithsonian Center for Astrophysics. 8:00 AM - 7:00 PM America Ballroom Foyer The Murchison Widefield Array (MWA), supported in the US by a grant from the National Science Foundation, is a first-generation instrument designed to detect and characterize redshifted 21cm signals from neutral hydrogen during the epoch of reionization at z~10. An important goal of the effort is to do pathfinding for subsequent generations of EoR instruments, and to directly inform the design of the planned Hydrogen Epoch of Reionization Array (HERA) phase 2 array. Such an instrument would be roughly 10 times larger than MWA. We describe the design of MWA, what we expect to learn from its use, and the ways we plan to use that knowledge in the HERA-II design. 132.09 Solar and Heliospheric Science with the Murchison Widefield Array Divya Oberoi1, L. D. Matthews1, L. Benkevitch1, I. H. Cairns2, J. C. Kasper3, A. J. Coster1, MWA Collaboration 1MIT Haystack Observatory, 2University of Sydney, Australia, 3Harvard-Smithsonian Center for Astrophysics. 8:00 AM - 7:00 PM America Ballroom Foyer Low radio frequencies (< 300 MHz) offer unique and powerful diagnostics of the Sun and heliosphere. Multiple reasons, however, conspire to make wide-band high-fidelity low radio frequency solar imaging challenging, including the dynamic and spectrally complex nature of solar emission, the large fields of view associated with low radio frequencies, and ionospheric distortion of incident radiation. Till recently this has limited the exploitation of low radio frequencies for solar and heliospheric studies. The recent and continuing advances in capacity and affordability of digital signal processing have enabled a new generation of instruments whose capabilities are well matched to the challenge of low radio frequency imaging. The Murchison Widefield Array (MWA) is amongst the first of these instruments and is currently under construction in the radio quiet Western Australian outback. The MWA will observe in the 80-300 MHz band and will comprise 512 elements, each with 16 dual polarization dipoles arranged in a 4x4 grid, distributed in a centrally condensed manner over a 1.5 km diameter with a small number of outliers extending the baselines to ~3 km. Its compact footprint and 130,816 physical baselines provide an unprecedented high-fidelity snap-shot imaging capability for every spectral channel, with 0.5-8 s time resolution and 40 kHz frequency resolution. Solar and heliospheric science is amongst the key science objectives of the MWA. In addition to solar imaging, the MWA will exploit propagation effects like interplanetary scintillation and Faraday rotation to study the solar wind in the inner heliosphere. Here we present a brief overview of the MWA solar and heliospheric science capabilities and some early results from a 32 element engineering prototype currently operating on site. The MWA collaboration includes US, Australian and Indian institutions and the US part of the collaboration is funded by the National Science Foundation. 132.10 A Conceptual Design Study for an Upgraded Dual-Channel Near-Infrared Imager/Spectrometer at the Shane 3m Telescope at Lick Observatory Emily C. Bowsher1, A. Burgasser1 1University of California San Diego. 8:00 AM - 7:00 PM America Ballroom Foyer A wide variety of astrophysical sources (cool brown dwarfs and exoplanets, obscured Galactic regions, high redshift SN/GRBs) are only accessible and/or characterizable at near-infrared (NIR) wavelengths. The development and declining costs of wide-format NIR detectors makes their use on 3-5m class telescopes for survey and synoptic studies an increasingly viable option. We describe a conceptual design study for a multichannel, NIR imager/spectrometer for the Shane 3m telescope at Lick Observatory, aimed to replace the existing Gemini camera (McLean et al. 1993). We perform a scientific cost/benefit analysis of various instrumentation features, including: tradeoffs in field-of-view, angular resolution and sensitivity; tradeoffs in long-wavelength detector cutoffs, cooling requirements and site environment; filter complement; capability for multiple dichroic options; inclusion of grism spectroscopy and polarimetry capabilities, and the option of a third optical (CCD) channel. We also examine these considerations in the context of existing 1-5m class NIR instrumentation, and identify areas in which the proposed instrument would enable unique and novel science. 132.11 ProtoEXIST: The Development of Advanced Tiled CZT Detector Planes for Wide Field Hard X-Ray Survey Telescope Branden Allen1, J. Hong1, J. Grindlay1, S. Barthelmy2, R. Baker2 1Harvard-Smithsonian CfA, 2NASA Goddard Space Flight Center. 8:00 AM - 7:00 PM America Ballroom Foyer ProtoEXIST is a technology development program for a coded aperture hard X-ray telescope with a large area (1-5 m$^2$) CZT detector plane for use in a future hard X-ray wide field sky monitor and survey telescope. The successful flight of the ProtoEXIST1 (P1) coded-aperture telescope concluded the first phase of the program on October 9, 2009. The black hole binary Cyg X-1 was imaged and its spectrum measured at the end of the (6h) flight. The P1 detector plane is comprised of a 8x8 array of detector crystal units (DCUs); each made up of a single 20 mm x 20 mm, 5 mm thick Redlen CZT crystal with a 8x8 pixilated anode (pixel pitch of 2.5 mm) bonded to an interposer board connecting each of the individual 64 anode pixels to a single input channel on a RadNET ASIC, forming a 256 cm^2 contiguous CZT imaging array with 4096 individual pixels. P1 was successfully recovered and has undergone further characterization in the interim. The program continues with the ongoing development ProtoEXIST2 (P2) utilizing a closely tiled 8x8 array of DCUs now with a reduced anode pixel pitch of 0.6 mm. Each DCU in P2 will consist of a CZT crystal, identical to that utilized in P1 now with a 32x32 pixelated anode, directly bonded to a single NuSTAR ASIC (Nu-ASIC). The fully assembled P2 imaging detector will be comprised of a semi-contiguous 256x256 array of pixels on 256 cm$^2$ of CZT. With its finer pixelation the P2 detector plane will enable 5' (FWHM) imaging with a 70 cm focal length and will be flown side-by-side with P1 from Ft. Sumner in the Spring of 2012. Results from the characterization of the P1 detector are discussed as well as current progress in the development of the P2 detector plane. 132.12 A Fast Scintillator Compton Telescope for Medium-Energy Gamma-Ray Astronomy Peter F. Bloser1, J. M. Ryan1, M. Julien1, J. S. Legere1, M. L. McConnell1, R. M. Kippen2, S. Tornga2, M. Wallace2 1Univ. of New Hampshire, 2Los Alamos National Laboratory. 8:00 AM - 7:00 PM America Ballroom Foyer The field of medium-energy gamma-ray astronomy urgently needs a new mission to build on the success of the COMPTEL instrument. This mission must achieve a sensitivity significantly greater than that of COMPTEL in order to advance the science of relativistic particle accelerators, nuclear astrophysics, and diffuse backgrounds and bridge the gap between current and future hard X-ray missions and the high-energy Fermi mission. Such an increase in sensitivity can only come about via a dramatic decrease in the instrumental background. We are currently developing a concept for a low-background Compton telescope that employs modern scintillator technology to achieve this increase in sensitivity. Specifically, by employing Lanthanum Bromide scintillators for the calorimeter, one can take advantage of the unique speed and resolving power of this material to improve the instrument sensitivity and simultaneously enhance its spectroscopic performance and thus its imaging performance. We present the design and calibration results of a small prototype of such an instrument, scheduled to fly on a balloon test flight in the Fall of 2011. We discuss the expected results from this test flight and the expected sensitivity of a full-scale instrument on a long-duration balloon mission. 132.13 Gamma II Thurburn Barker1, M. Castelaz1, J. Cline1, L. Owen1, J. Boehme1, L. Rottler1, C. Whitworth1, D. Clavier1 1Pisgah Astronomical Research Institute. 8:00 AM - 7:00 PM America Ballroom Foyer GAMMA II is the Guide Star Automatic Measuring MAchine relocated from STScI to the Astronomical Photographic Data Archive (APDA) at the Pisgah Astronomical Research Institute (PARI). GAMMA II is a multi-channel laser-scanning microdensitometer that was used to measure POSS and SERC plates to create the Guide Star Catalog and the Digital Sky Survey. The microdensitometer is designed with submicron accuracy in x and y measurements using a HP 5507 laser interferometer, 15 micron sampling, and the capability to measure plates as large as 0.5-m across. GAMMA II is a vital instrument for the success of digitizing the direct, objective prism, and spectra photographic plate collections in APDA for research. We plan several targeted projects. One is a collaboration with Drs. P.D. Hemenway and R. L. Duncombe who plan to scan 1000 plates of 34 minor planets to identify systematic errors in the Fundamental System of celestial coordinates. Another is a collaboration with Dr. R. Hudec (Astronomical Institute, Academy of Sciences of the Czech Republic) who is working within the Gaia Variability Unit CU7 to digitize objective prism spectra on the Henize plates and Burrell-Schmidt plates located in APDA. These low dispersion spectral plates provide optical counterparts of celestial high-energy sources and cataclysmic variables enabling the simulation of Gaia BP/RP outputs. The astronomical community is invited to explore the more than 140,000 plates from 20 observatories now archived in APDA, and use GAMMA II. The process of relocating GAMMA to APDA, re-commissioning, and starting up the production scan programs will be described. Also, we will present planned research and future upgrades to GAMMA II. 132.14 Adaptive Optics for the Giant Magellan Telescope Brian A. McLeod1, A. Bouchez2, R. Conan3, B. Espeland3, M. Hart4, P. Hinz4, M. van Dam5 1Harvard-Smithsonian, CfA, 2Giant Magellan Telescope, 3Australian National University, Australia, 4University of Arizona, 5Flat Wavefronts, New Zealand. 8:00 AM - 7:00 PM America Ballroom Foyer The adaptive optics system for the Giant Magellan Telescope will operate in three basic modes; natural guide star, laser tomography, and ground layer. The central component of the adaptive optics system, common to all modes, is a seven-segment adaptive secondary mirror. The natural guide star mode will enable high-contrast diffraction-limited imaging in the near-infrared in the vicinity of bright guide stars. Wavefront sensing will be done with a pyramid sensor. In the laser tomography mode, 6 laser guidestars measured with Shack-Hartmann wavefront sensors will be used to overcome focal anisoplanatism to achieve diffraction-limited imaging and spectroscopy in the infrared over 80% of the visible sky. A separate phase sensing system using faint natural guide stars is required to maintain equal pathlengths between the seven telescope apertures. In the final mode, the ground-layer adaptive optics system will use a wider constellation of laser guide stars to measure and correct the turbulence within a few hundred meters of the ground. This is expected to produce <0.3" FWHM images in the infrared over 10 arcmin fields of view under typical conditions. 132.15 Technology Development for Large Radio Arrays at the Jet Propulsion Laboratory Dayton L. Jones1, R. Preston1, R. Navarro1, K. Wagstaff1, C. Mattmann1, L. D'Addario1, D. Thompson1, W. Majid1, J. Lazio1 1JPL. 8:00 AM - 7:00 PM America Ballroom Foyer Future radio arrays are likely to include far more antennas than current arrays, ultimately culminating in the Square Kilometre Array. During the past 1.5 years JPL personnel have been working on technologies to address the challenges of such large arrays, including lower power digital signal processing, real-time data adaptive algorithms, and large-scale data archiving and mining. Power consumption by digital electronics may be a dominant component of the operating costs of large arrays. The choice of architecture for cross-correlation of thousands of antennas can have an orders-of-magnitude impact on power consumption. A power efficient architecture for a very-large-N array has been found. A second area of development at JPL is adaptive algorithms to perform real-time processing of data in high volume data flows, when storage of raw data for later processing is not an option. Algorithms to enable real-time detection of fast radio transients are being tested on the VLBA, and will be deployed as part of the CRAFT collaboration on ASKAP and potentially at other observatories. Finally, large radio arrays will produce extremely large data archives. We are working on applying a scalable framework for managing and mining large data archives to radio array needs. This framework is JPL's open source Process Control System, initially built for archiving data from NASA Earth Science missions and now used in a number of applications outside of astronomy. This work has been carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. 132.16 Recommissioning of HPOL, a Medium Resolution Spectropolarimeter James W. Davidson1, K. S. Bjorkman1, J. Hoffman2, J. Lomax2 1The University of Toledo, 2University of Denver. 8:00 AM - 7:00 PM America Ballroom Foyer We will report on the current status of the restoration of the Halfwave Polarimeter (HPOL) instrument, and present initial operational and science verification results from test observations carried out on the 1-meter telescope at Ritter Observatory at the University of Toledo. HPOL is a medium resolution spectropolarimeter, providing wavelength coverage from 3200 angstroms to 1.05 microns. It was previously a facility instrument at the Pine Bluff Observatory of the University of Wisconsin, but it has been off-line since October 2004. Our group has been working on restoring HPOL, in collaboration with astronomers at the University of Wisconsin and the University of Minnesota, with the eventual goal of relocation to the 60 inch telescope at the Mt. Lemmon Observing Facility, operated by the University of Minnesota. In addition to ongoing science programs on circumstellar disks and stellar polarimetry, a primary science objective for the refurbished HPOL will be investigations of potential polarization signatures from extrasolar planets. Initial targets will include HD189733b, which has had some recent polarimetry results reported in the literature, as well as several transiting planet systems. The refurbishment of HPOL has been partially funded by a Small Research Grant from the AAS. 132.17 Preparing for the First Balloon Flight of the Gamma-Ray Polarimeter Experiment (GRAPE) Taylor Connor1, M. Mark1, C. Bancroft1, P. Bloser1, J. Legere1, J. Ryan1 1UNH. 8:00 AM - 7:00 PM America Ballroom Foyer We have developed a design for a hard X-ray polarimeter operating in the energy range from 50 to 500 keV. This modular design, known as GRAPE (Gamma-Ray Polarimeter Experiment), has been successfully demonstrated in the lab using partially polarized gamma-ray sources and using fully polarized photon beams at Argonne National Laboratory. In June of 2007, a GRAPE engineering model, consisting of a single detector module, was flown on a high altitude balloon flight to further demonstrate the design and to collect background data. We are currently preparing a much larger balloon payload for a flight in the fall of 2011.  Using a large (16-element) array of detector modules, this payload is being designed to search for polarization from known point sources of radiation, namely the Crab and Cygnus X-1.  This first flight will not only provide a scientific demonstration of the GRAPE design (by measuring polarization from the Crab nebula), it will also lay the foundation for subsequent long duration balloon flights that will be designed for studying polarization from gamma-ray bursts and solar flares. Here we shall present data from calibration of the first flight module detectors, review the latest payload design and update the predicted polarization sensitivity for both the initial continental US balloon flight and the subsequent long-duration balloon flights. 132.18 Observing Solar and Jovian Radio Bursts Joseph Grippaldi1 1TCNJ. 8:00 AM - 7:00 PM America Ballroom Foyer A recently constructed low frequency radio telescope has been constructed on the campus of the The College of New Jersey (TCNJ) has recently begun conducting observations at ~20MHz as part of NASA'a Radio Jove program. This instrument is capable of observations of Jovian radio emission including strong prompt radio emission associated with the Jovian moon Io. We will discuss Jovian observations conducted with this instrument as an effort to conduct coincident observation with the Eight-meter-wavelength Transient Array (ETA) and the Long Wavelength Array (LWA). 132.19 Observations of Solar Radio Transients Giorla Paige1 1TCNJ. 8:00 AM - 7:00 PM America Ballroom Foyer A low frequency radio telescope has been recently been constructed on the campus of the The College of New Jersey (TCNJ) and has begun conducting observations at ~20MHz as part of NASA'a Radio Jove program. This instrument is capable of observations of solar radio emission including strong prompt radio emission associated with solar burst events. We will discuss solar observations conducted with this instrument as well as an effort to conduct coincident observations with the Eight-meter-wavelength Transient Array (ETA) and the Long Wavelength Array (LWA). 133 Star Clusters and Associations - Galactic & Extra-galactic Poster Session America Ballroom Foyer 133.01 Characterizing the Nearest Old Cluster - Ruprecht 147 Jason L. Curtis1, J. T. Wright1 1The Pennsylvania State University. 8:00 AM - 7:00 PM America Ballroom Foyer Ruprecht 147 has recently been identified as the nearest old cluster, theoretically enabling it to serve as an important benchmark for fundamental stellar astrophysics. Past attempts at characterization have been hindered by a limited (and in one case, a completely erroneous) membership list and poor photometry. We have conducted a radial velocity survey of candidates with MMT/Hectochelle and identify high-confidence members. We have obtained deep CFHT/MegaCam g'r'i'z' photometry, and combined with archival 2MASS JHK photometry, we perform a 7-band isochrone fit to break the degeneracy between extinction and distance to constrain the age, using the tau-squared maximum-likelihood procedure of Naylor & Jefferies (2007). We are working to publish and disseminate online our catalog of cluster and stellar properties, offering the community several new avenues for research in stellar astrophysics. 133.02 A New Look at the Old Cluster NGC 6791 Imants Platais1, K. M. Cudworth2, V. Platais-Kozhurina3, D. E. McLaughlin4, S. Meibom5, C. Veillet6 1Johns Hopkins Univ., 2Yerkes Obs., 3STScI, 4Keele Univ., United Kingdom, 5Harvard-Smithsonian, CfA, 6CFHT Corp.. 8:00 AM - 7:00 PM America Ballroom Foyer We present comprehensive cluster membership and g'r' photometry of the prototypical old, metal-rich Galactic star cluster NGC 6791. The proper motion catalog contains 58901 objects down to g'=23.5, limited to a circular area of radius 30 arcmin. The highest precision of the proper motions is 0.08 mas/yr. Our proper motions confirm cluster membership of all main and also some rare constituents of NGC 6791. The total number of probable cluster members down to g'=22 is about 4800. New findings include an extended horizontal branch in this cluster. The angular radius of NGC 6791 is at least 15 arcmin. The luminosity function of the cluster peaks at g'=18.5 and then steadily declines toward fainter magnitudes. We note a presence of differential reddening in NGC 6791 and argue that it is a more plausible agent to produce the observed dichotomy of main sequence near the turn-off. This work is supported in part by a NSF grant 09-08114 to JHU. 133.03 Chandra Observations of the Well-Studied 180 Myr Old Open Cluster M35 Soren Meibom1, S. H. Saar1, S. A. Barnes2 1Harvard-Smithsonian,CfA, 2Lowell Observatory. 8:00 AM - 7:00 PM America Ballroom Foyer M35 is a relatively close (~800 pc), rich, young (~180 Myr) open cluster which has been the focus of extensive multi-epoch spectroscopic and photometric study. Some 250 single and 100 binary stars (~50 with orbits) are confirmed members and 310 have measured rotation periods. This detailed information about membership, binarity, and rotation, makes M35 an ideal target for studying not only the rotation-activity-age relation for cool stars, but also for the effect of a stellar companion on this relationship. We present preliminary results of a 130 ksec ACIS-I observation near the core of the M35, containing ~180 cluster members. We explore how the coronal flux and temperature change across the cluster's color-period diagram, how binarity affects these results, and compare our findings with other clusters. This work was funded by Chandra Award No. GO0-11041A. 133.04 A Broad-band And Intermediate-band Photometric Study Of The Intermediate-age Open Cluster, Ngc 5822 Barbara J. Anthony-Twarog1, G. Carraro2, E. Costa3, B. Jones1, B. Twarog1 1Univ. of Kansas, 2ESO, Chile, 3Univ. of Chile, Chile. 8:00 AM - 7:00 PM America Ballroom Foyer CCD photometry on the UBVI system has been obtained and analyzed for an area 40’ x 40' centered on the open cluster NGC 5822. CCD photometry on the uvbyCaHβετα system has also been obtained and analyzed for the core region of the cluster. The intermediate-band data for 110 probable single-star A and F cluster members show that the cluster is only mildly reddened, with E(B-V) = 0.104, but is superposed on a field where the typical background star has E(B-V) > 0.4, making separation of the cluster from the field using intermediate-band data a straightforward process down V = 17. From 61 F dwarfs, the metallicity from m1and hk is [Fe/H] = -0.02. Combining the reddening and metallicity with appropriate isochrones produces an age estimate of 0.95 Gyr, with an uncertainty below 0.1 Gyr. 133.05 The Open Cluster Tombaugh 5 in the Vilnius and IPHAS Systems Laugalys Vygandas1, K. Zdanavicius1, J. Zdanavicius1, F. J. Vrba2, V. Straizys1, R. P. Boyle3 1ITPA Vilnius University, Lithuania, 2USNO, 3Vatican Observatory. 8:00 AM - 7:00 PM America Ballroom Foyer Abstract. Tombaugh 5 is a little investigated open cluster located in the direction of the Camelopardalis complex of dust clouds (RA = 3h47.8m, DEC = +59d03.2m). We investigated the area of 20'x20' size, centered on the cluster, applying CCD frames taken with the 1 m telescope of the USNO Flagstaff Station in the seven-color Vilnius photometric system with the passbands at 345, 374, 405, 466, 516, 544 and 656 nm, supplemented by a broad-band I filter. Magnitudes and color indices for 674 stars down to V = 17.7 mag were obtained. Spectral types and luminosity classes were determined using interstellar reddening-free Q-parameters. These data allowed us to calculate interstellar extinctions and distances, and to plot the color-magnitude diagram for stars dereddened individually. This diagram is used to identify cluster members and to determine its age and distance. Magnitudes and color indices from the IPHAS survey, together with the data from the Vilnius system, were used to investigate the distribution of interstellar extinction with distance in various directions within the field. 133.06 Photometric Study of Intermediate Age Open Clusters Maria Eugenia Contreras1, R. Michel1, W. Schuster1, C. Chavarria-Kleinhenn1, L. Olguin2 1Inst. De Astronomia, UNAM, Mexico, 2Depto. de Investigacion en Fisica, Universidad de Sonora, Mexico. 8:00 AM - 7:00 PM America Ballroom Foyer We present the study of a sample of intermediate age open clusters (age ~ 10-30 Myr) using optical (UBVRI) and infrared (JHK) photometric data. Optical photometry was obtained as part of the San Pedro Martir Open Clusters Project (SPM-OCP, Schuster et al. 2007; Michel et al. 2011, in preparation) while near-infrared photometry was retrieved from the 2MASS public data archive (ref). Most of the clusters included in SPM-OCP were selected from the Dias et al. (2002). catalog. On one hand, UVRI photometry was used to derive fundamental parameters of each cluster in the sample, such as age, distance and reddening. On the other hand, infrared photometry has allowed us to carry out a preliminary search of candidate stars to posses a circumstellar disk detected via its near-infrared excess. Observational data show that the number of infrared excess detection decreases with stellar age and actually this emission seems to completely disappear in stars with an age of ~30 Myr (Strom et al. 1993; Muzerolle et al. 2000). One possible explanation for the lack of infrared emission has been proposed to be grain coagulation where small dust particles grow into larger and larger bodies until forming planetesimals and even planets. In this work we are aimed to analyze a sample of open clusters lying in this crucial age range. 133.07 Is This Really A Cluster?: Using 2MASS and GLIMPSE for SDSS-III/APOGEE Cluster Target Selection Kelly Jackson1, P. M. Frinchaboy1 1Texas Christian University. 8:00 AM - 7:00 PM America Ballroom Foyer Which of the star cluster candidates from within the inner Milky Way galaxy are actual clusters? Utilizing data collected from the 2MASS and Spitzer/GLIMPSE-I, II, 3D, and 360 surveys, we present first results utilizing a new technique to isolate nearby open stars clusters. Once a cluster is confirmed, we use the "cleaned" CMD to measured the cluster age, metallicity, and distance. In addition for a selection of clusters, the likely cluster members identified by this technique will be targeted as part of the SDSS-III/APOGEE survey. This work was partially supported by NASA/JPL, an NSF REU grant (NSF 0851558) and funding from Texas Christian University, including a Science and Engineering Research Center (TCU-SERC) grant. 133.08 Chandra Observations Of The Massive Young Association Cygnus OB2 Nicholas James Wright1 1Harvard-Smithsonian Center for Astrophysics. 8:00 AM - 7:00 PM America Ballroom Foyer Cygnus OB2 is one of the most massive known star clusters in our Galaxy, and also one of the closest at a distance of only ~1.5 kpc. Its proximity offers the unique opportunity to probe the structure, dynamics, and low-mass stellar component of a young star cluster that is often impossible in other, more distant clusters. Its role as an important benchmark for studies of stellar clusters has been highlighted by recent Chandra, Spitzer and Herschel surveys of the region. I will present results from Chandra observations of the center of Cygnus OB2 that have allowed us to efficiently identify ~1500 members of the cluster, largely complete in our field of view down to 1 solar mass. These observations are complemented by optical and near-IR photometry from a number of recent deep surveys of the Galactic Plane that were used to identify and separate foreground stars and estimate masses and extinctions for cluster members based on fitted isochrones. This has provided a number of insights into the star formation history of the region, the stellar mass function, and the circumstellar disk fraction that all suggest that a significant fraction of the cluster is older than the commonly accepted age of 2 Myrs. This has implications for the timescales of star formation and its propagation throughout massive clusters. I will also discuss the Chandra Cygnus OB2 Legacy Survey, a recently completed 1 square degree survey of the entire cluster that will facilitate large-scale studies of the stellar populations and disk properties in the harsh environments prevalent in young clusters. It will also provide the first opportunity to study the large scale star formation process in detail, including a planned radial velocity follow-up survey that will probe the dynamical evolution and disruption of a young stellar cluster for the first time. 133.09 Clues to the Star Formation in NGC 346 across Time and Space Guido De Marchi1, N. Panagia2, E. Sabbi2 1European Space Agency, Netherlands, 2Space Telescope Science Institute. 8:00 AM - 7:00 PM America Ballroom Foyer We have studied the properties of the stellar populations in the field of the NGC 346 cluster in the Small Magellanic Cloud, using the results of a novel self-consistent method that provides a reliable identification of pre-main sequence (PMS) objects actively undergoing mass accretion, regardless of their age. The 680 identified bona-fide PMS stars show a bimodal age distribution, with two roughly equally numerous populations peaked respectively at ~ 1 Myr, and ~ 16 Myr. We use the age and other physical properties of these PMS stars to study how star formation has proceeded across time and space in NGC 346. We find no correlation between the locations of young and old PMS stars, nor do we find a correspondence between the positions of young PMS stars and those of massive OB stars of similar age. Furthermore, the mass distribution of stars with similar age shows large variations throughout the region. We conclude that, while on a global scale it makes sense to talk about an initial mass function, this concept is not meaningful for individual star-forming regions. An interesting implication of the separation between regions where massive stars and low-mass objects appear to form is that high-mass stars might not be ``perfect'' indicators of star formation and hence a large number of low-mass stars formed elsewhere might have so far remained unnoticed. For certain galaxies with low surface density this way of preferential low-mass star formation may be the predominant mechanism, with the consequence that their total mass as derived from the luminosity may be severely underestimated and that their evolution is not correctly understood. 133.10 The Effect on Cluster Evolution of Stellar Evolution Model Choice Using AMUSE Alfred J. Whitehead1, S. L. W. McMillan1, S. Portegies Zwart2, E. Vesperini1 1Drexel University, 2Leiden Observatory, Netherlands. 8:00 AM - 7:00 PM America Ballroom Foyer Star clusters are typically modelled by computer simulation using N-Body gravitational dynamics and stellar evolution "recipes", which are derived from detailed stellar models. These recipes range from simple curve fits to data tables, through interpolation between precisely solved stellar structure models, all the way to fully-fledged "live" stellar physics simulations. A set of initial conditions is created using one of a common set of theoretical models, such as the Plummer or King models. These models typically describe a star cluster using continuum properties, such as density. A set of stars is generated which closely follows this distribution using a random number generator. In this work we examine the impact of the choice of stellar evolution recipe on the lifetime and evolution of a cluster. Additionally, we investigate the noise introduced into the simulation by using a randomly generated discrete realization of a continuous initial condition model. These simulations are conducted using a new community-based simulation framework called AMUSE (the Astrophysical Multipurpose Software Environment). Switching between the most commonly used models of stellar evolution, with no other changes to the simulation, can change the cluster lifetime by as much as 25 percent. 133.11 Color Bimodality of Extragalactic Globular Clusters: A Test for the Nonlinear Color-Metallicity Relation Scenario via the $u$-band Colors Suk-Jin Yoon1, S. T. Sohn2, J. Cho1, S. Lee1, H. Kim1, C. Chung1 1Yonsei Univ., Korea, Republic of, 2STScI. 8:00 AM - 7:00 PM America Ballroom Foyer The colors of globular clusters (GCs) in most large elliptical galaxies are bimodal. Based on the observed linear relations between GC colors and their metallicities, the bimodality is taken as evidence of two GC subsystems with different metallicities in each galaxy and has led to a number of theories in the context of galaxy formation. More recent observations and modeling of GCs, however, suggest that colors likely trace metallicities in a subtly nonlinear manner. The nonlinearity could even transform a broad, unimodal metallicity spread into a strongly bimodal color distribution. Despite the far-reaching implications, whether color-metallicity relations (CMRs) are nonlinear and whether the nonlinearity indeed causes the color bimodality are still open questions. Given that the spectroscopic refinement of CMRs is still very challenging, we here propose a new photometric tool to probe the possible nonlinear nature of CMRs. In essence, a color distribution of GCs is a “projected” distribution of their metallicities based on a given CMR. Since the form of CMRs hinges on which color is used, the shape of color distributions varies depending significantly on colors in use. Among other optical colors, the u-band colors (e.g., u-g and u-z) are theoretically predicted to exhibit the most distinctive CMRs from other preferred CMRs (e.g., for g-z). As a case study, we performed the HST/WFPC2 archival u-band photometry for the M87 GC system with confirmed color bimodality. We show that any weak yet discernible feature on CMRs is amplified appreciably on the color domain by the projection effect, and hence, under the assumption of the nonlinear CMRs, the u-band color distributions are significantly different and readily distinguishable from those under the assumption of the conventional linear CMRs. With more data, this method will support or rule out the nonlinear-CMR scenario for GC color bimodality with high confidence. 133.12 Globular Cluster Colors Versus Population Synthesis Models Pauline Barmby1, F. F. Jalilian1 1Univ. of Western Ontario, Canada. 8:00 AM - 7:00 PM America Ballroom Foyer Although the stellar populations of globular clusters are not as simple as we used to believe, they are still the simplest populations available in the nearby universe. As such, they are extremely useful for testing stellar population synthesis models. Using recent mass estimates for Local Group globular clusters, we have compiled a sample of clusters with masses large enough that stochastic effects on integrated photometry should be minimal. We have measured integrated colors in the Spitzer/IRAC bands for as many of these as possible, paying careful attention to systematics in order to get the most accurate colors. We present a comparison of the results with the predictions of the latest generation of population synthesis models, including GALEV and FSPS. Support for this work was provided by a Discovery Grant and an Undergraduate Summer Research Award from NSERC and by an Ontario Early Researcher Award. 133.13 Dynamical Stability and Long-term Evolution of Rotating Stellar Systems Anna L. Varri1, E. Vesperini2, S. L. W. McMillan2, G. Bertin3 1Drexel University and Universita' degli Studi di Milano, 2Drexel University, 3Universita' degli Studi di Milano, Italy. 8:00 AM - 7:00 PM America Ballroom Foyer We present the first results of an extensive survey of N-body simulations designed to investigate the dynamical stability and the long-term evolution of two new families of self-consistent stellar dynamical models, characterized by the presence of internal rotation. The first family extends the well-known King models to the case of axisymmetric systems flattened by solid-body rotation while the second family is characterized by differential rotation. The equilibrium configurations thus obtained can be described in terms of two dimensionless parameters, which measure the concentration and the amount of rotation, respectively. Slowly rotating configurations are found to be dynamically stable and we followed their long-term evolution, in order to evaluate the interplay between collisional relaxation and angular momentum transport. We also studied the stability of rapidly rotating models, which are characterized by the presence of a toroidal core embedded in an otherwise quasi-spherical configuration. In both cases, a description in terms of the radial and global properties, such as the ratio between the ordered kinetic energy and the gravitational energy of the system, is provided. Because the role of angular momentum in the process of cluster formation is only partly understood, we also undertook a preliminary investigation of the violent relaxation of simple systems initially characterized by approximate solid-body rotation. The properties of the final equilibrium configurations thus obtained are compared with those of the above-described family of differentially rotating models. 134 Laboratory Astrophysics and Catalogs Poster Session America Ballroom Foyer 134.01 Charge Exchange Studies for Solar System X-ray Emission Modeling Yong Wu1, J. Nolte1, P. Stancil1, D. Schultz2, Y. Hui2, H. Lieberman3, R. Buenker3, R. Shelton1, I. Draganic2, C. Havener2 1University of Georgia, 2Oak Ridge National Laboratory, 3Bergische Universitat Wuppertal, Germany. 8:00 AM - 7:00 PM America Ballroom Foyer As most of the gas in the Universe is not in thermal equilibrium, accurate modeling and interpretation of observations requires understanding of a variety of collisional processes. When ions and neutrals are present, charge exchange is one such process. While it can be important for the ionization balance, it can also affect ion emission spectra, such as in the case of the solar wind charge exchange (SWCX) mechanism. While charge exchange cross sections can be measured and/or calculated, the enhancements in the spectral line resolution and sensitivity from current X-ray observatories (Chandra, XMM-Newton, Suzaku), and planned missions (e.g., IXO and Astro-H) place severe demands on the collisional data. As a consequence, the construction of reliable charge exchange datasets for atmospheric and astrophysical modeling faces a number of challenges: i) Due to the quantity of required data at the quantum-state-resolved level, theory must provide the bulk of the results with experiment serving as benchmarks. ii) The accuracy of the scattering calculations is directly dependent on the reliability and availability of the quantum structure/chemical data. iii) Database construction requires consistent and appropriate funding which is typically lacking. We review these issues in the context of our on-going collaborative work on charge exchange calculations and measurements for SWCX modeling. Cross sections, diagnostic line ratios, and x-ray yields will be presented for collisions of C^5+, N^6+, O^6+, O^7+ with H and their role in X-ray emission from Earth's geocorona, the exosphere of Mars, Jupiter, comets, the heliosphere, and astrospheres will be discussed. This work was partially supported by NASA grants NNX09AV46G, NNG09WF24I, and NNH07ZDA001N. 134.02 Recent Progress with the CHIANTI Atomic Database for Astrophysical Spectroscopy Kenneth P. Dere1 1George Mason Univ.. 8:00 AM - 7:00 PM America Ballroom Foyer The first version of the CHIANTI atomic database for astrophysical spectroscopy was released in 1997 and the most recent version in 2009. Recent progress with CHIANTI will be described. Based on the ionization rates developed by Dere (2007) and the radiative and dielectronic recombination rates of Badnell and colleagues, a new set of ionization balance calculations has been calculated. These show some substantial difference from previous calculations. A suite of Python programs, ChiantiPy, has been developed to allow users to use the CHIANTI database to calculate spectral line and continuum intensities in an object-oriented manner. This package is also the basis for a developmental web server that can show the results of specifically requested calculations through a user web browser. The direction of future work with CHIANTI will be outlined. 134.03 Accurate Photodissociation in UV and X-ray Irradiated Molecular Gas Phillip C. Stancil1, C. D. Gay1, R. M. Cieszewski1, W. el-Qadi1, A. Kuri1, S. Miyake1, N. Abel2, R. L. Porter1, G. Shaw3, G. J. Ferland4, P. A. M. van Hoof5 1Univ. of Georgia, 2Univ. of Cincinnati, 3Centre for Excellence in Basic Science, India, 4Univ. of Kentucky, 5Royal Observatory of Belgium, Belgium. 8:00 AM - 7:00 PM America Ballroom Foyer Molecules are primarily destroyed in diffuse and translucent regions, in protoplanetary disks, in cool stellar atmospheres, in photodissociation regions, and in x-ray dominated regions via photodissociation (PD) due to the incident radiation field. The majority of astrochemical/spectral modeling codes available today use pre-computed exponentially-attenuated photorates based on dust scattering/absorption for an ``average" interstellar cloud. Since there is clearly a large scatter in the dust properties and local radiation field for various environments in the Galaxy and beyond, the adoption of such pre-computed photorates can lead to considerable errors in predicted abundances. To improve current modeling capabilities, we are computing new rovibrationally-resolved PD cross sections for H_2, HD, HeH+, NH, C_2, CN, and CS and implementing the cross sections in the spectral simulation code Cloudy for explicit computation of local photorates. We present model results using the new photodissociation cross sections for a variety of environments emphasizing differences in total and state-specific molecular column densities. This work was partially supported by NASA grants NNG06GJ11G and HST-AR-11776.01-A, NSF grant AST-0607733, and the PRODEX Programme of ESA. 134.04 Molecular Photoabsorption Cross Sections In The Ultraviolet: N2, SO2, S2, CO2 Peter L. Smith1, G. Stark2, D. Blackie3, J. C. Pickering3, B. R. Lewis4, A. N. Heays4 1Retired, 2Wellesley College, 3Imperial College, United Kingdom, 4Australian National University, Australia. 8:00 AM - 7:00 PM America Ballroom Foyer Our research program focuses on the measurement of ultraviolet molecular photoabsorption cross sections with the highest practical resolution. It supports efforts to interpret and model observations of planetary atmospheres. Measurement efforts on molecular nitrogen, sulfur dioxide, diatomic sulfur, and carbon dioxide are in progress. N2: We focus on the measurement of line f-values and line widths within the complex spectrum between 80 and 100 nm. Our measurements are incorporated into a theoretical model of N2 which has established the mechanisms responsible for predissociation and reproduces all observed absorption features in 14N2 and its isotopologues as a function of temperature. SO2: Using the Imperial College UV Fourier transform spectrometer, we have completed and published cross sections at room temperature from 198 to 325 nm, at 198 K from 213 to 325 nm, and at 160 K from 199 to 220 nm. S2: Interpretations of atmospheric (Io, Jupiter, cometary comae) S2 absorption features are hindered by a complete lack of laboratory cross section data in the ultraviolet. We are working to quantify the photoabsorption spectrum of S2 from 200 to 300 nm based on laboratory measurements and theoretical calculations. We have designed an experimental apparatus to produce a stable column of S2 vapor. Measurements of the absorption spectrum of S2 at high resolution will be complemented by coupled-channel calculations. CO2: The photodissociation of CO2 is a fundamental photochemical process in the atmospheres of Mars and Venus. Our research centers on the measurement of high resolution cross sections from 87 to 120 nm. We have completed measurements at 295 K and 195 K over the 106 to 120 nm region, and we have recorded preliminary data of the room temperature spectrum in the 87 to 106 nm region. 134.05 Radiative Shock Waves In Emerging Shocks R. Paul Drake1, F. Doss1, A. Visco1 1Univ. of Michigan. 8:00 AM - 7:00 PM America Ballroom Foyer In laboratory experiments we produce radiative shock waves having dense, thin shells. These shocks are similar to shocks emerging from optically thick environments in astrophysics in that they are strongly radiative with optically thick shocked layers and optically thin or intermediate downstream layers through which radiation readily escapes. Examples include shocks breaking out of a Type II supernova (SN) and the radiative reverse shock during the early phases of the SN remnant produced by a red supergiant star. We produce these shocks by driving a low-Z plasma piston (Be) at > 100 km/s into Xe gas at 1.1 atm. pressure. The shocked Xe collapses to > 20 times its initial density. Measurements of structure by radiography and temperature by several methods confirm that the shock wave is strongly radiative. We observe small-scale perturbations in the post-shock layer, modulating the shock and material interfaces. We describe a variation of the Vishniac instability theory of decelerating shocks and an analysis of associated scaling relations to account for the growth of these perturbations, identify how they scale to astrophysical systems such as SN 1993J, and consider possible future experiments. Collaborators in this work have included H.F. Robey, J.P. Hughes, C.C. Kuranz, C.M. Huntington, S.H. Glenzer, T. Doeppner, D.H. Froula, M.J. Grosskopf, and D.C. Marion ________________________________ * Supported by the US DOE NNSA under the Predictive Sci. Academic Alliance Program by grant DE-FC52-08NA28616, the Stewardship Sci. Academic Alliances program by grant DE-FG52-04NA00064, and the Nat. Laser User Facility by grant DE-FG03-00SF22021. 134.06 Oscillator Strengths and Predissociation Rates for W - X Bands of CO and Its Isotopologues Steven Robert Federman1, Y. Sheffer2, M. Eidelsberg3, J. L. Lemaire3, G. Stark4, J. H. Fillion5, J. Lyons6, P. L. Smith7, B. R. Lewis8, A. N. Heays8, N. de Oliveira9, M. Roudjane9 1Univ. of Toledo, 2Univ. of Maryland, 3Obs. de Paris, Meudon, France, 4Wellesley, 5Univ. UMPC, France, 6UCLA, 7CfA, 8ANU, Australia, 9Synchrotron SOLEIL, France. 8:00 AM - 7:00 PM America Ballroom Foyer The photochemistry of carbon monoxide plays an important role in many astrophysical environments, including photon-dominated regions in interstellar clouds, circumstellar disks around newly formed stars, and the envelopes surrounding stars near the end of their lives. It controls the CO abundance and the ratio of its isotopologues. We are conducting experiments on the DESIRS beam-line at the SOLEIL Synchrotron to acquire the necessary data on oscillator strengths and predissociation rates for modeling CO photochemistry. A VUV Fourier Transform Spectrometer provides a resolving power of about 300,000, allowing us to discern individual lines in electronic transitions. Here we focus on results for W - X (v´=0-3, 0) bands seen in spectra of 12C16O, 13C16O, 12C18O, and 13C18O and compare them with earlier determinations. Since we are using a differentially-pumped system, an accurate measure of the column of gas is needed. The most suitable band for calibration appears to be B - X (0, 0), but even here special care is required. 134.07 Reverse Radiative Shock Experiments Relevant to Accreting Stream-Disk Impact in Interacting Binaries Christine Krauland1, R. P. Drake1, C. K. Kuranz1, C. M. Huntington1, M. J. Grosskopf1, D. C. Marion1, R. Young1, T. Plewa2 1University of Michigan, 2Florida State University. 8:00 AM - 7:00 PM America Ballroom Foyer In many Cataclysmic Binary systems, mass onto an accretion disk produces a ‘hot spot’ where the infalling supersonic flow obliquely strikes the rotating accretion disk. This collision region has many ambiguities as a radiation hydrodynamic system, but shock development in the infalling flow can be modeled. Depending upon conditions, it has been argued (Armitage & Livio, ApJ 493, 898) that the shocked region may be optically thin, thick, or intermediate, which has the potential to significantly alter the hot spot’s structure and emissions. We report the first experimental attempt to produce colliding flows that create a radiative reverse shock at the Omega-60 laser facility. Obtaining a radiative reverse shock in the laboratory requires producing a sufficiently fast flow (> 100 km/s) within a material whose opacity is large enough to produce energetically significant emission from experimentally achievable layers. We will discuss the experimental design, the available data, and our astrophysical context. Funded by the NNSA-DS and SC-OFES Joint Prog. in High-Energy-Density Lab. Plasmas, by the Nat. Laser User Facility Prog. in NNSA-DS and by the Predictive Sci. Acad. Alliances Prog. in NNSA-ASC, under grant numbers are DE-FG52-09NA29548, DE-FG52-09NA29034, and DE-FC52-08NA28616. 134.08 Blast-Wave-Driven Instability Experiments Relevant To Supernova Hydrodynamics Carolyn Kuranz1, R. Drake1, M. Grosskopf1, A. Budde1, B. Remington2, H. Robey2, D. Arnett3, C. Meakin3, T. Plewa4 1University of Michigan, 2Lawrence Livermore National Laboratory, 3University of Arizona, 4Florida State University. 8:00 AM - 7:00 PM America Ballroom Foyer This presentation discusses experiments scaled to the blast wave driven instabilities at the He/H interface during the explosion phase of SN1987A. This core-collapse supernova was detected about 50 kpc from Earth making it the first supernova observed so closely to earth in modern times. The progenitor star was a blue supergiant with a mass of ~18-20 solar masses. A blast wave occurred following the supernova explosion because there was a sudden, finite release of energy. Blast waves consist of a shock front followed by a rarefaction wave. When a blast wave crosses an interface with a decrease in density, hydrodynamic instabilities will develop. These experiments include target materials scaled in density to the He/H layer in SN1987A. About 5 kJ of laser energy from the Omega Laser facility irradiates a 150 µm plastic layer that is followed by a low-density foam layer. A blast wave structure similar to those in supernovae is created in the plastic layer. The blast wave crosses an interface with a drop in density and a precision-machined interface with multiple modes. The specific modal structure is based on simulation results of the evolution of the progenitor star. This produces unstable growth dominated by the Rayleigh-Taylor (RT) instability. We have detected the interface structure under these conditions, using dual orthogonal radiography, and will show some of the resulting data. This work is funded by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, grant number DE-FG52-09NA29548, and by the National Laser User Facility Program, grant number DE-FG52-09NA29034. 134.09 High Temperature Line Lists For Carbon Monoxide From Microwave Discharge Spectroscopy Farnood REZAIE1, P. Figueiredo1, J. Arnold1, R. Peale1 1UCF. 8:00 AM - 7:00 PM America Ballroom Foyer In gas giant exoplanets that orbit close to their parent stars, known as hot Jupiters, carbon is thought to be sequestered primarily in carbon monoxide and methane. The relative CO and CH4 abundances inform us about temperature and pressure conditions and also about mixing by global winds driven by intense but asymmetric heating for these tidally-locked bodies. Emission spectra collected during secondary eclipses, as the hot Jupiter passes behind its parent star, in principle allows a determination of the CO:CH4 concentration ratio. Since hot Jupiters exist at temperatures of order 1000 K, accurate model atmospheres require high temperature line lists for relevant molecules, for which existing data bases are apparently incomplete. Here we present high temperature emission spectra of CO. The spectra were obtained using a microwave discharge apparatus where the source of CO was carbon dioxide that dissociates under microwave heating. The pressure inside the discharge tube was of order 1 Torr and the microwave power applied to the cavity was ~70 W. Emission exited the discharge tube via a ZnSe window and entered through a NaCl window the emission port of the evacuated Fourier spectrometer. The spectrum was measured in the range 1800-2400 cm-1 at a resolution of 0.1 cm-1 using a KBr beamsplitter and a 77 K InSb detector. Vibrational transitions V(1->0) centered at 2147 cm-1 and V(2->1) at 2120 cm-1 were clearly identified. From the J values for maximum intensity lines within the rotational fine structure we obtain a temperature estimate of ~1400 K, which is comparable to the atmospheric conditions of hot-Jupiters. Obtained line lists are compared with existing information in the HITRAN database. 134.10 TGCat: A Catalog and Archive of Chandra High-Resolution X-Ray Spectra David Huenemoerder1, A. Mitschang2, D. Dewey1, M. Nowak1, N. S. Schulz1, J. S. Nichols3, J. E. Davis1, J. C. Houck1, H. L. Marshall1, M. S. Noble4, D. Morgan3, C. R. Canizares5 1MIT Kavli Institute for Astrophysics and Space Research, 2Macquarie University, Australia, 3SAO, 4Broad Institute, 5MIT. 8:00 AM - 7:00 PM America Ballroom Foyer The Chandra Transmission Grating Data Archive and Catalog (TGCat) provides easy access to analysis-ready high-resolution X-ray spectra. The web interface makes it easy to find observations of a particular object, type of object, or type of observation, and to quickly assess the quality and potential usefulness of the spectra from pre-computed summary plots. An interacitve plotter provides the ability to visualize spectra possibly combined over multiple observations) in a variety of flux units against a choice of wavelength or energy axes; any plot so created can be downloaded as an ASCII table. For detailed analysis, the data files themselves can be retrieved. The query results themselves can be saved as ASCII or Virtual Observatory tables. Portable reprocessing scripts used to create the archive and which use the CXC's and other publicly available software are also available. Support for this work was provided by NASA through SAO contract SV3-73016 to MIT for support of the Chandra X-ray Center. Monday, May 23, 2011, 8:00 AM - 8:30 AM 100 Welcoming Address Invited Session America Ballroom Welcome Address Arne A. Henden1 1AAVSO. America Ballroom Monday, May 23, 2011, 8:30 AM - 9:20 AM 101 Kavli Lecture: The 2050 Decadal Survey of Astronomy and Astrophysics Invited Session America Ballroom 101.01 The 2050 Decadal Survey of Astronomy and Astrophysics Malcolm Longair1 1Cavendish Laboratory, Cambridge, United Kingdom. 8:30 AM - 9:20 AM America Ballroom Astronomy, Astrophysics and Cosmology have changed out of all recognition over the last 40 years. The lecture will review some of the key scientific, technological and sociological changes which have contributed to that revolution and seek to understand the issues of maintaining that drive for discovery and understanding over the next 40 years. Some science objectives are well defined, but others may need new concepts, unexpected discoveries and quite a bit of good luck. A personal perspective will be presented on topics which the community should take seriously for the advance of astronomy and astrophysics and the role it can play for the betterment of society. Monday, May 23, 2011, 10:00 AM - 11:30 AM 102 12-Years of Science with Chandra: Chandra Observations of the Solar System Meeting-in-a-Meeting America North 102.01 The Chandra X-Ray Observatory: Current Status and Future Prospects Martin C. Weisskopf1 1NASA's MSFC. 10:00 AM - 10:15 AM America North This presentation serves as an introduction to the Meeting in a Meeting (MiM) “12 Years of Science with Chandra”. Chandra’s superb, sub-arcsecond, angular resolution --- a capability which will, unfortunately, not be matched or surpassed for years to come --- is the inspiration for this MiM. Chandra’s spectacular images and detailed spectra of astrophysical systems ranging from solar system objects to distant galaxies and galaxy clusters have provided information on such diverse topics as the properties of planetary and cometary atmospheres, stellar formation and demise, black hole-galaxy-cluster interactions, and properties of dark matter and dark energy. We present a overview and status report on the Observatory, its future prospects, and mention some recent highlights not covered by other speakers in the 6 sessions of the MiM. 102.02 High Resolution X-ray Views of Solar System Objects Graziella Branduardi-Raymont1 1Mullard Space Science Laboratory, University College London, United Kingdom. 10:15 AM - 10:45 AM America North Over the last decade Chandra, and XMM-Newton, have revealed the beauty and multiplicity of X-ray emissions in our solar system: high resolution data, in both spectral and spatial domains, have been crucial in disentangling the physical processes at work. The talk will review the main findings in this area at the boundary between astrophysics and planetary science, and will show how the solar system offers ‘next door’ examples of widespread astrophysical phenomena. Jupiter shows bright X-ray aurorae, arising from the interactions of local and/or solar wind ions, and electrons, with its powerful magnetic environment: the ions undergo charge exchange with atmospheric neutrals and generate soft X-ray line emission, and the electrons give rise to bremsstrahlung X-rays. Chandra's unparalleled spatial resolution has shown how the X-ray footprints of the electrons in the aurorae coincide with the bright FUV auroral oval, indicating that the same electron population is likely to be at the origin of both emissions. Moreover, Jupiter's disk scatters solar X-rays, displaying a spectrum that closely resembles that of solar flares. Saturn has not revealed X-ray aurorae (yet), but its disk X-ray brightness, like Jupiter’s, is strictly correlated with the Sun's X-ray output. A bright X-ray spot has also been resolved by Chandra on the eastern ansa of Saturn's rings, and its spectrum suggests an origin in the fluorescent scattering of solar X-rays on the rings icy particles. Both Mars and Venus have X-ray emitting disks and exospheres, which can be clearly resolved at high spectral and spatial resolution. And the Earth has bright X-ray aurorae that have been targets of Chandra observations. Finally, comets, with their extended neutral comae and extremely line-rich X-ray spectra, are spectacular X-ray sources, and ideal probes of the conditions of the solar wind in the Sun’s proximity. 102.03 Heliospheric Solar-Wind Charge Exchange Bradford J. Wargelin1 1Harvard-Smithsonian, CfA. 10:45 AM - 11:15 AM America North X-ray emission from solar wind charge exchange (SWCX) arises in the Earth's exosphere and throughout the solar system in the heliosphere. The intensity of SXCW emission observed by X-ray telescopes from within these emission regions varies a great deal, both as a function of viewing geometry and solar activity. SWCX accounts for much or most of the soft X-ray background (SXRB) but distinguishing it from Galactic emission is a tricky problem. One approach is to measure the SXRB at a given point on the sky at different times and with different lines of sight through the heliosphere. The Chandra Deep Field-South, comprising 52 observations and 4 Msec of data collected between 2000 and 2010, is uniquely suited for such studies. This talk will also discuss the potential of high-spectral-resolution observations and prospects for measuring mass-loss rates around other stars from their charge exchange emission. Support for this work was provided by NASA through Chandra Award Number SP1-12001X issued by the Chandra X-ray Observatory Center (CXC), which is operated by the Smithsonian Astrophysical Observatory for and on behalf of NASA under contract NAS8-03060. 102.04 X-rays from Planetary Exospheres: What we can Learn Konrad Dennerl1 1Max Planck Institute for Extraterrestrial Physics, Germany. 11:15 AM - 11:30 AM America North X-ray observations have opened up a completely new possibility of remote global imaging of planetary exospheres and their spatial and temporal variability. The talk will focus on the planets Venus and Mars, where the absence of a global magnetic field enables a straightforward study of how a planetary atmosphere responds to the incident solar photon and ion flux. Chandra was the first satellite to detect X-rays from Venus and Mars and to reveal that they are the result of two different processes: scattering of solar X-rays and charge exchange reactions between highly charged heavy ions in the solar wind with atmospheric neutrals. As a consequence of the characteristic photoabsorption cross sections, scattering of solar X-rays is most efficient at atmospheric heights of 100-140 km, i.e., well above the cloud layers. Here, X-rays provide direct observational access to regions which are difficult to study by in-situ measurements or by remote observations at other wavelengths. X-ray observations of charge exchange reactions in planetary exospheres have a particulary high scientific potential, because this process is considered as an important nonthermal escape mechanism, which may be responsible for a significant loss of the atmosphere. Although this process is mainly due to charge exchange with solar wind protons, which are about 1000 times more abundant than heavy ions and which do not produce X-rays, the high cross section makes charge exchange an efficient tracer of planetary outgassing, thus linking X-ray astrophysics to astrobiology. 103 AAVSO: Astrophysics with Small Telescopes Special Session America Central 103.01 Contributions by Citizen Scientists to Astronomy Arne A. Henden1 1AAVSO. 10:00 AM - 10:15 AM America Central The AAVSO's experience in utilizing the skills, equipment and enthusiasm of amateur astronomers towards its research is not unique in astronomy. Citizen Scientists have contributed to our understanding of asteroids, exo-planets, solar system weather, light echoes, and galactic streaming, as well as inventing new equipment and software. This talk will highlight some of the recent advances by Citizen Scientists, and suggest some areas where they can contribute in the future. 103.02 The Z CamPaign Early Results Mike Simonsen1 1AAVSO. 10:15 AM - 10:30 AM America Central The Z CamPaign is an observing project designed to acquire enough detailed, long-tem data to unambiguously classify dwarf novae as bona fide members of the Z Cam sub-type or not. Because the defining characteristic of all Z Cam dwarf novae are "standstills", a temporary period of relative quiet between maximum and minimum light, we are monitoring these systems for this specific activity. Amateur astronomers are gathering all the data with backyard telescopes as part of an AAVSO Cataclysmic Variable Section observing initiative. We will discuss the organization, science goals, and present early results of the Z CamPaign. 103.03 Cataclysmic Variables in the Backyard Joseph Patterson1 1Columbia University. 10:30 AM - 10:45 AM America Central The last decade has seen plummeting prices and significant advances in CCD-camera and smart-telescope technology, reaching all the way to the humblest of telescopes. There are now thousands of well-equipped amateur astronomers interested in using their telescopes for research, and many hundreds already doing so in coordinated campaigns. Variable star science has benefited tremendously. Since it's always dark and always clear somewhere, coordinated photometry can accumulate nearly 24-hour coverage... and since the observers own their telescopes, very long campaigns are feasible, with little worry about weather. I'll describe one network of observers, the Center for Backyard Astrophysics (CBA). The telescope apertures are 20-50 cm, enabling good signal-to-noise and time resolution down to V=18. We organize campaigns of time-series photometry of cataclysmic variables (novae, dwarf novae, magnetic variables, some X-ray binaries) - and routinely achieve thousand-hour campaigns with no significant aliasing, since the telescopes are distributed around the world. This enables sensitive searches for periodic signals, extending even to long time scales (months). We now produce most of the world's supply of accretion-disk precession periods, and keep close watch on all the other clocks in cataclysmic variables (orbit, white-dwarf rotation and pulsation, and quasiperiodic oscillations). 103.04 Planet Hunting with HATNet and HATSouth Gaspar Bakos1 1Harvard-Smithsonian Center for Astrophysics. 10:45 AM - 11:00 AM America Central Transiting exoplanets (TEPs), especially those found around bright stars, are particularly important as they provide unique opportunities to study the physical properties of planetary mass objects. The HATNet project---one of the small telescope surveys---has been extremely successful in the field of TEPs, contributing 27 published discoveries, and one independent discovery of a previously published planet. Publications on several additional planetary systems are in preparation. I will discuss how HATNet operates around the globe, and how these fully automated small (11cm diameter) telescopes produce big science. I will also mention the related HATSouth project, now in full operation, and monitoring selected southern fields round-the-clock. Finally, I will conclude on how small and big telescopes collaborate in exoplanet science. 103.05 Lessons Learned During the Recent Epsilon Aurigae Eclipse Observing Campaign Robert E. Stencel1 1Univ. of Denver Observatories. 11:00 AM - 11:15 AM America Central The 18 month long eclipse of the 3rd magnitude star, epsilon Aurigae, is forecast to end during May 2011, based on six eclipse events, in 2010, 1982, 1955, 1930, 1902 and 1874. In partnership with AAVSO, Hopkins Phoenix Observatory and others, we have organized observing campaigns during the past several years in order to maximize data acquired during this rare event and to promote reporting and analysis of observations of all kinds. Hundreds of registered participants have signed up for alert notices and newsletters, and many dozens of observers have contributed photometry, spectra and ideas to the ongoing effort - see websites: www.CitizenSky.org and www.hposoft.com/Campaign09.html . In this presentation, I will provide an update on the participation leading to extensive photometric results. Similarly, bright star spectroscopy has greatly benefited from small telescope plus spectrometer capabilities, now widely available, that complement traditional but less-frequent large telescope high dispersion work. Polarimetry provided key insights during the last eclipse, and we promoted the need for new data using this method. Finally, interferometry has come of age since the last eclipse, leading to the direct detection of the transiting dark disk causing the eclipse. Along with these traditional measurements, I will outline campaign-related efforts to promote Citizen Science opportunities among the public. Support for these efforts derives in part from AAVSO/NSF-Informal Science Education, NSF AAG grant 10-16678 and a bequest to the University of Denver Astronomy Program by alumnus William Herschel Womble, for which I am grateful. 103.06 Long-Term Visual Light Curves and Modern Visual Observing in Astrophysics John R. Percy1 1Univ. of Toronto, Canada. 11:15 AM - 11:30 AM America Central Thanks to organizations such as the AAVSO, visual observations of variable stars have scientific strengths: they are numerous, sustained, and standardized. Though many have predicted the demise of visual observation, the demand for visual observations increased dramatically in the last quarter of the 20th century. In addition to their value in detecting, timing, and studying outbursts in CVs, fadings in R CrB stars, and eclipses in binaries, they are uniquely useful in studying the behavior of pulsating stars, especially slow, irregular, and long-term behavior. In this presentation, I will give a general review of this topic, but will highlight the nature and implications of my own work on such stars: Mira stars, smaller-amplitude pulsating red giants, RV Tauri and SRd variables, and supergiant variables across the H-R diagram. This work includes studies of variability, periodicity, multiperiodicity, irregularity, period changes (systematic and random), and long-term variability of unknown cause. This work provides important information about stellar processes, properties, structure, and evolution. For studying long-term variability, the AAVSO International Database is a uniquely valuable resource. Much of this work has been carried out by students, motivated by the excitement of doing real science, with real data, thereby developing and integrating their science, math, and computing skills. We present at AAVSO meetings, and publish in the JAAVSO, as feedback and motivation to observers. Acknowledgements: I thank NSERC Canada for research support, my students for their work and inspiration, and the AAVSO staff and observers who make this work possible. 104 "New Worlds, New Horizons": The Science of Astro2010 Special Session America South 104.01 The Science of "New World, New Horizons": an Introduction Timothy M. Heckman1 1John Hopkins University. 10:00 AM - 10:15 AM America South "New Worlds, New Horizons in Astronomy & Astrophyics" (NWNH) lays out a broad, ambitious, and exciting suite of scientific opportunities in the coming decade. In my talk I will give an overview of this landscape and summarize three focused areas highlighted in NWNH: 1) Cosmic Dawn: Searching for the First Stars, Galaxies, and Black Holes 2) New Worlds: Seeking Nearby Habitable Planets 3) Physics of the Universe: Understandin Scientific Principles. 104.02 Cosmology and Fundamental Physics David N. Spergel1 1Princeton Univ. Obs.. 10:15 AM - 10:30 AM America South The Astro2010 Science Frontier Panel Cosmology and Fundamental Physics' scope encompassed the early universe, the microwave background, the reionization and galaxy formation up to virialization of protogalaxies, large scale structure, the intergalactic medium, the determination of cosmological parameters, dark matter, dark energy, tests of gravity, astronomically determined physical constants, and high energy physics using astronomical messengers. The Panel identified 4 questions that it believed will form the focus for research in the coming decade: (1) How did the Universe Begin? (2) Why is the Universe Accelerating? (3) WHat is the Dark Matter? and (4) What Are the Properties of Neutrinos? The panel also identified gravity wave astronomy as a discovery area of tremendous promise. 104.03 Astro2010 Science in the Galactic Neighborhood (Redshift z < 0.1) J. Michael Shull1 1Univ. of Colorado. 10:30 AM - 10:45 AM America South The GAN (Galactic Neighborhood) Science Frontier Panel of the Astro2010 decadal study provided 4 science questions and 2 discovery areas ripe for investment. Defining our "neighborhood" out to redshift z = 0.1 (420 Mpc), we focused on: (1) Flows of matter and energy in and out of galaxies; (2) Cycles of mass, energy, and chemistry within galaxies and their ISM; (3) Fossil record of galaxy assembly, from the first stars to the present; (4) Connections between dark and luminous matter in galaxies and black holes. Our panel was excited about the promise of two Discovery Areas: (A) Time-Domain Astronomy, to explore the transient sky and stellar populations, including spectroscopic follow-up; and (B) Astrometry of objects ranging from extra-solar planets to halo stars, masers, globular clusters, galaxies, and quasars (maser disks, bound stars). 104.04 Galaxies Across Cosmic Time C. Megan Urry1 1Yale Univ.. 10:45 AM - 11:00 AM America South The Astro2010 Science Frontier Panel Galaxies Across Cosmic Time (GCT) study encompassed the main constituents of the universe across 90 percent of its history, from the formation and evolution of structures such as galaxies, clusters of galaxies, and the “cosmic web” of intergalactic matter, to the stars, gas, dust, supermassive black holes, and dark matter of which they are composed. These elements are coupled in a complicated evolutionary progression as matter accretes into galaxies, stars form and evolve, black holes grow, supernovae and active galactic nuclei expel matter and energy into the intergalactic medium (IGM), and galaxies collide and merge. The GCT panel was charged with formulating 4 questions and identifying one area with unusual discovery potential that it believes will form the focus for research in the coming decade. The questions are: (1) How do cosmic structures form and evolve? (2) How do baryons cycle in and out of galaxies, and what do they do while they are there? (3) How do black holes grow, radiate, and influence their surroundings? (4) What were the first objects to light up the universe and when did they do it? We identified the epoch of reionization as the Discovery Area. This presentation reviews highlights from the GCT report, some of which imply a need for new observational facilities, whereas others could be done with existing facilities, possibly with a reprogramming of resources. 104.05 Planetary systems and star formation in the Astro2010 survey Dan M. Watson1, on behalf of the Astro2010 panel on Planetary Systems and Star Formation 1University of Rochester. 11:00 AM - 11:15 AM America South The panel on Planetary Systems and Star Formation was tasked with identifying the major frontiers of Galactic astronomy for the next decade, in the wake of the exponential growth of exoplanet discovery, the results of missions such as Spitzer, Herschel and Kepler, and the promise of improvements in angular resolution, image contrast and sensitivity in space and in ground-based observations. From our study emerged four questions on which major further progress seems likely, and one area in which the potential for discovery seems especially high: (1) How do stars form? In particular, what determines the rate and efficiencies of star formation, and the stellar and prestellar-core mass functions? (2) How do circumstellar disks evolve and form planetary systems? In particular, how do giant planets accrete from disks, what are infant giant planets and their formation environment like, and what constraints on the planet-forming process emerge from the observed structure of debris disks? (3) How diverse are planetary systems? What may be revealed by a complete census of architecture, and planetary bulk and atmospheric composition? (4) Do habitable words exist in orbit around other stars? What characteristics define habitability, and how can we measure these characteristics? (+1) Is there a fast track for identification of a nearby habitable exoplanet? How can we exploit the relative ease with which planets can be detected around lower-mass stars, and the large numbers of M stars in our neighborhood? 104.06 Stars and Stellar Evolution: the Next Decade Roger Chevalier1 1Univ. of Virginia. 11:15 AM - 11:30 AM America South The science frontier for stars and stellar evolution is as close as the Sun and as distant as exploding stars at redshift 8.3. The field includes the Sun as a star, stellar astrophysics, the structure and evolution of single and multiple stars, compact objects, supernovae, gamma-ray bursts, solar neutrinos, and extreme physics on stellar scales. The following 4 questions appear promising for advances: (1) How do rotation and magnetic fields affect stars? (2) What are the progenitors of Type Ia supernovae and how do they explode? (3) How do massive stars end their lives? (4) What controls the mass, radii, and spins of compact stellar remnants? Stellar astronomy will benefit from a wide range of multiwavelength observations, but observations in the time domain are especially well-suited to stellar problems. With regard to theory, computer resources are developing to the point where 3-dimensional simulations with realistic physics are becoming feasible and should play a crucial role in solving a number of outstanding problems. 106 Spiral Galaxies, Computation, Data Handling, Image Analysis & Other Topics Oral Session Staffordshire 106.01 Stellar Streams in the Andromeda Halo Mark A. Fardal1, PAndAS collaboration 1University of Massachusetts. 10:00 AM - 10:10 AM Staffordshire The PAndAS survey detects RGB and AGB stars in our neighbor galaxy M31, out to 150 kpc from the galaxy center with an extension to M33. Maps of this survey display a spectacular collection of stellar streams extending tens to hundreds of kpc in length. Many of these streams overlap with each other or with M31's central regions, making it difficult to disentangle the different streams. I discuss what is currently known about the nature, origin, significance, and eventual fate of these stellar streams. Photometric observations from the PAndAS survey and follow-up work constrain the metallicity, age, luminosity, and stellar mass of the stellar population. I discuss scenarios for how some of these streams formed, while for others their origin remains a mystery. I present observationally constrained numerical simulations for the formation of some of the streams. The streams also are probes of the mass profile and lumpiness of M31's dark matter halo. Spectroscopic samples are used to constrain M31's halo mass at large radius. 106.02 New Catalog of H II Regions in M31 Mohaddesseh Azimlu1, P. Barmby1, R. Marciniak1 1University of Western Ontario, Canada. 10:10 AM - 10:20 AM Staffordshire We present a new catalog of HII regions in M31. The galaxy is observed as part of the Local Group Galaxies survey. We used HIIphot, a code for automated photometry of HII regions, to identify HII regions and measure their fluxes and sizes. HIIphot fits boundaries with irregular morphologies and can avoid overlapping in crowded regions. A S/N=10 detection level was used to exclude diffuse gas fluctuations and star residuals after continuum subtraction. Our catalog of 4368 objects is complete to a luminosity of L(Hα)=10e34 erg/s. This is five times fainter than the only previous CCD-based study which contained 981 objects in the NE half of M31. We have detected very faint regions created by individual OB stars and resolved most of them in crowded regions. They are responsible for 80% of the total Hα emission. We determined the HII luminosity function (LF) by fitting a power law to luminosities larger than 10e36.7 and determined a slope of 2.52±0.07. A second peak at L(Hα)=10e35 suggests a star burst between 15 and 20 million years ago which is consistent with UV star formation history studies. No significant difference was observed between in-arm and inter-arm LFs, but the inter-arm regions are less populated (37% of total detected regions) and constitute only 12% of the total luminosity of L(Hα)= 5.6e40 erg/s(after extinction correction). A star formation rate of 0.42 M_sun/yr was estimated from the Hα total luminosity which is consistent with the determination from the Spitzer 8μm data. We found a poor spatial correlation between the HII regions and young clusters. We conclude that these clusters are older than the lifetime of the HII regions. which is in agreement with the UV studies of star forming history in M31 which suggest a decrease in star formation rate in the recent past. 106.03 Enigmatic Masks of Cosmic Dust: 8.0μm Morphology of Nearby Barred Spiral Galaxies Robert Groess1, D. L. Block1, G. G. Fazio2 1University of the Witwatersrand, South Africa, 2Harvard Smithsonian Center for Astrophysics. 10:20 AM - 10:30 AM Staffordshire Early observations of barred galaxies, such as NGC1300, NGC1530, NGC3351 and NGC5921 by Curtis, revealed the prevalence of characteristic dark bands or streaks across the disk of the galaxy. These dark bands were interpreted to be lanes of “occulting material” obscuring luminous objects behind them. While being nothing more than a nuisance to observers at the turn of the twentieth century, it is these lanes of dust to which we now turn, seen glowing in emission at 8.0μm. Comparing Spitzer IRAC images of a sample of nearby barred galaxies, we find a separation of 3.6μm images into two distinct classes or form families. The first class comprises galaxies whose 8.0μm morphology tightly traces the underlying barred stellar backbone at 3.6μm, while the second class does not reveal a bar at all at 8.0μm. Spectacular lanes of dust are however evident in this second class and are understood to be signatures of shock loci at the outer edges of the bar. These two distinct form families are discussed in greater detail. 106.04 Understanding the Schmidt-Sanduleak Law of Star Formation Barry F. Madore1, E. Murphy1 1Carnegie Observatories. 10:30 AM - 10:40 AM Staffordshire We introduce a new diagnostic diagram for illuminating and interpreting the observed rate of star formation in nearby galaxies. Fundamentally the new plot underlies the spatially-resolved Schmidt-Sanduleak relation, and provides novel physical insight into the origins of that higher-level relation between tracers of star formation activity and spatially-averaged surface gas densities. 106.05 Evolution of Dense Gas with Starburst Age: When Star Formation Versus Dense Gas Relations Break Down David S. Meier1, J. L. Turner2, E. Schinnerer3 1New Mexico Institute of Mining and Technology, 2UCLA, 3Max-Plank-Institut fur Astronomie, Germany. 10:40 AM - 10:50 AM Staffordshire Dense gas correlates well with star formation on kpc scales. On smaller scales, motions of individual clouds become comparable to the ~100 Myr ages of starbursts. One then expects the star formation rate vs. dense gas relations to break down on giant molecular cloud scales. We exploit this to study the evolutionary history of nuclear starburst in the nearby spiral, IC 342. Maps of the J=5-4 and 16-15 transitions of dense gas tracer HC3N at ~20 pc resolution made with the VLA and the Plateau de Bure interferometer are presented. The 5-4 line of HC3N traces very dense gas in the cold phase, while the 16-15 transition traces warm, dense gas. These reveal changes in dense cloud structure on scales of 30 pc among clouds with star formation histories differing by only a few Myrs. HC3N emission does not correlate well with young star formation at these high spatial resolutions, but gas excitation does. The cold, dense gas extends well beyond the starburst region implying large amounts of dense quiescent gas not yet actively forming stars. Close to the starburst the high excitation combined with faint emission indicates that the immediate (30 pc) vicinity of the starburst lacks large masses of very dense gas and has high dense gas star formation efficiencies. The dense gas appears to be in pressure equilibrium with the starburst. We propose a scenario where the starburst is being caught in the act of dispersing or destroying the dense gas in the presence of the expanding HII region. This work is supported by the NSF through NRAO and grant AST-1009620. 106.06 Characterization Of The Willard L. Eccles Observatory For Optical Astronomy Dennis Della Corte1, K. Dawson1, N. Ramsrud1, W. Springer1 1University of Utah. 10:50 AM - 11:00 AM Staffordshire The Willard L. Eccles Observatory (WEO) on Frisco Peak in southwestern Utah was commissioned in the fall of 2010. I will present the processing pipeline for all images taken at WEO. The automated routine is able to extract calibration files from each date of observation and unite them with flat field images taken in the laboratory. We then apply this analysis pipeline to the data taken to determine important site characteristics such as atmospheric extinction and seeing. 106.07 Norman Rockwell's "Man's First Step On The Moon" Timothy Barker1 1Wheaton College. 11:00 AM - 11:10 AM Staffordshire Rockwell’s painting, which appeared in the January 10, 1967 issue of Look magazine, is perhaps the most famous ever done of an astronaut’s first step on the Moon. But it has a number of astronomical misconceptions, many of which are apparent to sharp-eyed introductory astronomy students: the size of the Earth in the lunar sky is too large compared to the Big Dipper, the orbiting Command Service Module is illuminated from a different direction than the Earth is, and the lighting on the lunar surface is also inconsistent, among other errors. This raises the question: How could Rockwell, a notoriously meticulous illustrator, have apparently been so careless? It turns out that Rockwell was anything but careless, but rather was typically obsessive about every detail in the painting. He was in constant communication with experts, even traveling to Huston to meet with NASA officials. He went so far as to enlist the help of space artist Pierre Mion, who ended up doing part of the painting, one of only two known collaborations between Rockwell and another artist. When the Look article was published, readers responded with praise but also criticism about the technical errors that still slipped through, to Rockwell’s great frustration. The most important part of the painting, however, is accurate and compelling: the astronaut is shown stepping off the LM exactly as Neil Armstrong would do over two years later. The astronaut’s boot covers part of the shadow that it casts. Does the shadow run all the way to the heel, or is the boot poised just above the lunar surface? Has the artist captured the instant after, or, perhaps, the instant before, humanity’s first contact with another world? I am grateful to the curators at the Norman Rockwell Museum Archives for their assistance. 107 Black Holes Oral Session St. George CD 107.01 Flares from Disruptions of White Dwarfs by Intermediate Mass Black Holes Roman Shcherbakov1, R. Haas2, T. Bode2, P. Laguna2 1Harvard University, 2Georgia Institute of Technology. 10:00 AM - 10:10 AM St. George CD Tidal disruptions of white dwarfs (WDs) by intermediate mass black holes (IMBHs) may produce detectable electromagnetic/gravitational wave signature. They may provide the evidence for existence of IMBHs. We simulate the disruptions in full numerical general relativity (GR) with MayaKranc + Whisky code combination for several BH spin values. We model X-ray and UV time-dependent spectra from the simulations. Direct emission from hot fallback material is substantial, when the BH spin is aligned with WD orbital angular momentum. However, the fallback material can be completely shielded by large Compton optical depth in a misaligned case. This emphasizes the importance of realistic GR simulations with misaligned spin. Properties of flares from shock breakout region depend less on spin orientation and value. We discuss the prospects of positive identifications of candidates from GALEX and other surveys. 107.02 Optical Discovery of Stellar Tidal Disruption Flares Glennys R. Farrar1 1New York Univ.. 10:10 AM - 10:20 AM St. George CD Using archival SDSS multi-epoch imaging data (Stripe 82), we have searched for the tidal disruption of stars by super-massive black holes in non-active galaxies. Two candidate tidal disruption events (TDEs) are identified, using a pipeline with high rejection efficiency and minimal selection bias. Their properties are examined using i) SDSS imaging to compare them to other flares observed in the search, ii) UV emission measured by GALEX and iii) spectra of the hosts and of one the flares. This evidence shows that a SN or AGN-flare explanation is not viable. The flares are unlike any SN observed to date -- the spectra and strong late-time UV emission being particularly distinctive. Statistical arguments and host Hubble-type show it is highly unlikely that they are type IIn SNe or members of a previously-unobserved class of SNe. Furthermore, the strength of the candidate TDE flares is far greater than seen in variable AGNs and their hosts are much quieter in off-seasons than hosts of AGN flares. The properties of the flares are readily understood assuming they are examples of the stellar tidal disruption phenomenon. Our search is most sensitive to black hole masses ~10^7 Msun and the measured rate is consistent with theoretical predictions for black holes in this range. The TDE flares have optical black-body temperatures 2x10^4 K and M_g = -18.3 and -20.4; their cooling rates are very low. We infer that hundreds or thousands of TDEs will be present in current and next-generation optical synoptic surveys. Using the approach outlined here, a TDE candidate sample with O(1) purity can be selected using geometric resolution and host and flare color alone, demonstrating that a campaign to create a large sample of tidal disruption events, with immediate and detailed multi-wavelength follow-up, is feasible. 107.03 Soft X-ray Lags In XTE J1550-564 With Rxte: Evidence Of A Link To Outflow And Jet. Nikolai Shaposhnikov1 1University of Maryland. 10:20 AM - 10:30 AM St. George CD I will report on a detailed analysis of RXTE data from the galactic black hole candidate XTE J1550-564 during rising phase of the 1998 outburst. Specific focus is made on the behavior of the time lags and their correlation with other properties observed in X-ray and radio wavelengths. The main result of the presented study is a strong connection between the soft lags, in which variability in the hard X-rays leads the variability in the soft X-rays, and radio emission activity. Observed correlations suggest a link between soft lags and outflow phenomenon (e.g. wind or jet). In addition, a strong spike in the negative time lags occurred during a powerful high energy flare which precedes the radio flare by approximately one day. This directly relates the strong soft lags with the ejection of the relativistic jet. This newly discovered effect should have important implication to the physical picture of accretion and jet ejection in black hole sources. 107.04 Signatures of Recoiling Black Holes in AGN and Galaxy Merger Remnants Laura Blecha1, T. J. Cox2, A. Loeb1, L. Hernquist1 1Harvard University, 2Carnegie Observatories. 10:30 AM - 10:40 AM St. George CD Central supermassive black holes (SMBHs) are a ubiquitous feature of locally-observed galaxies, and ample evidence suggests that the growth of SMBHs and their host galaxies is closely linked. However, in the event of a merger, gravitational-wave (GW) recoil may displace a SMBH from its galactic center, or eject it entirely. To explore the consequences of this phenomenon, we use hydrodynamic simulations of gaseous galaxy mergers that include a range of BH recoil velocities. We have generated a suite of over 200 simulations with more than 60 merger models, enabling us to identify systematic trends in the behavior of recoiling BHs -- specifically (i) their dynamics, (ii) their observable signatures, and (iii) their effects on BH/galaxy co-evolution. (i) Recoiling BH trajectories depend heavily on the gas content of the host galaxy; maximal BH displacements from the center may vary by up to an order of magnitude between gas-rich and gas-poor mergers. In some cases, recoil trajectories also depend on the timing of the BH merger relative to the formation of the galaxy merger remnant. (ii) Recoiling BHs may be observable as offset active galactic nuclei (AGN) via either kinematic offsets (Δv > 800 km s-1) or spatial offsets (ΔR > 1 kpc) for lifetimes of about 1 - 100 Myr. In addition, recoil events affect the total AGN lifetime. GW recoil generally reduces the lifetimes of bright AGN, but may actually extend lower-luminosity AGN lifetimes. (iii) Rapidly-recoiling BHs may be up to about 5 times less massive than their stationary counterparts. These mass deficits lower the normalization of the MBH - σ* relation and contribute to both intrinsic and overall scatter. Furthermore, recoil events displace AGN feedback from the galactic center, which enhances central star formation rates. This results in longer starburst phases and higher central stellar densities in merger remnants. 107.05 Linking Variability in the Accretion Disk Wind and Radio Jet in the β State of GRS 1915+105 Joseph Neilsen1, J. C. Lee1 1Harvard University. 10:40 AM - 10:50 AM St. George CD We present new results from the Chandra HETGS on the accretion disk wind in the bizarre β state of GRS 1915+105. Renowned for its discrete jet ejections and its implications for the disk-jet connection around accreting black holes, the β state is a ~30-minute limit cycle featuring strong and unusual X-ray spectral variability. We report our analysis of two HETGS observations of this state, focusing on the properties of X-ray absorption lines from the accretion disk wind during known intervals of jet formation and accretion disk variability. We find that the wind is prominent throughout the limit cycle, but that it has a lower column density and a higher ionization parameter during the characteristic long, spectrally-hard dip (which may be associated with discrete ejections), and a higher column density and lower ionization parameter during periods of strong disk variability. We discuss these results in the context of rapid physical interactions between the accretion disk wind and the radio jet, and consider implications for similar classes of X-ray variability. 107.06 Evolution Of Correlations Between Low-mass Black Holes And Host Galaxies Qirong Zhu1, Y. Li1 1Penn State University. 10:50 AM - 11:00 AM St. George CD The correlation between low-mass black holes and their host galaxies is an interesting topic in galaxy formation and evolution. Recent observations have shown the M-sigma relation at low mass differ from the relation of the massive elliptical galaxies. Here we present results from cosmological high-resolution hydrodynamic simulations using the Aquila initial conditions focusing on a Milky Way-sized halo. Different physical processes besides gas dynamics are included especially star formation and black hole growth and feedback. We find an evolution of both the Fundamental Plane(FP) relation and M-sigma correlation. We expect galaxies have a higher velocity dispersion for a higher redshift. Such galaxies, if containing a central black hole, would fall below the M-sigma relation defined by elliptical galaxies before the system reaches equilibrium. However, there is not much evolution in the M-M* correlation across cosmic time which indicated some relation between their growth histories. Our results suggest that these well-known correlations have different origins: the M-sigma and FP relations are results of dynamical virialization of the system, while M-M* is the result of regulated star formation and black hole growth. 107.07 X-ray Spectra from MHD Simulations of Accreting Black Holes Jeremy Schnittman1, S. Noble2, J. Krolik3 1NASA/GSFC, 2RIT, 3JHU. 11:00 AM - 11:10 AM St. George CD We present new global calculations of X-ray spectra from fully relativistic magneto-hydrodynamic (MHD) simulations of black hole (BH) accretion disks. With a self-consistent radiative transfer code including Compton scattering and returning radiation, we can reproduce the predominant spectral features seen in decades of X-ray observations of stellar-mass BHs: a broad thermal peak around 1 keV, power-law continuum up to >100 keV, and a relativistically broadened iron fluorescent line. By varying the mass accretion rate, different spectral states naturally emerge: thermal-dominant, steep power-law, and low/hard. In addition to the spectral features, we briefly discuss applications to X-ray timing and polarization. 107.08 Modeling Electromagnetic Signatures of Supermassive Black Hole Binaries Resolvable by Pulsar Timing Arrays Takamitsu Tanaka1, K. Menou1, Z. Haiman1 1Columbia University. 11:10 AM - 11:20 AM St. George CD Pulsar Timing Arrays (PTAs) are expected to detect the collective gravitational-wave (GW) nanohertz background emitted by the population of compact supermassive black hole (SMBH) binaries in our cosmic neighborhood. Recent studies have suggested that: (i) the most massive or nearby sources may stick out above the background and be individually resolved; and (ii) PTAs may be able to constrain the sky positions and luminosity distances of resolved systems. We present a semianalytic toy model for accretion disks around such SMBH binaries. This model predicts thermal emission properties that differ from standard disk models around solitary SMBHs and thus may aid the electromagnetic identification of resolved PTA sources. Successful multi-messenger observations of these objects would complement cosmic expansion studies that utilize type-Ia supernovae, and allow follow-up astronomical studies of nearby SMBH binaries. 108 The Galactic Center Oral Session Gloucester 108.01 Fermi Bubbles: A 10 Kpc Shock From The Galactic Center? Meng Su1, T. Slatyer1, D. Finkbeiner1 1Harvard University. 10:10 AM - 10:20 AM Gloucester Data from the Fermi-LAT reveal two large gamma-ray bubbles, extending 50 degrees above and below the Galactic center, with a width of about 40 degrees in longitude. The gamma-ray emission associated with these bubbles has a significantly harder spectrum (dN/dE ~ E^{−2}) than the IC emission from electrons in the Galactic disk, or the gamma-rays produced by decay of pions from proton-ISM collisions. The bubbles are spatially correlated with the hard-spectrum microwave excess known as the WMAP haze; the edges of the bubbles also line up with features in the ROSAT X-ray maps at 1.5 − 2 keV. I will summarize observational evidence of the Fermi bubbles, including features of polarization and rotation measure of the bubble edges. The bubbles have sharp edges in gamma-ray, X-ray, and polarized microwave. I'm going to argue that these Galactic gamma-ray bubbles are ongoing shocks (instead of a stable structure), and were most likely created by some large episode of energy injection in the Galactic center, such as past accretion events onto the central massive black hole, or a nuclear starburst in the last ∼10 Myr. 108.02 Discovery of a Significant Magnetic CV Population in the Galactic Center Region JaeSub Hong1, J. Grindlay1, M. van den Berg2, M. Servillat1, P. Zhao3 1Harvard Univ., 2Utrecht University, Netherlands, 3Harvard-Smithsonian Center for Astrophysics. 10:20 AM - 10:30 AM Gloucester The large number (>3000) of the low-luminosity (10^30-33 erg/s at 8 kpc) X-ray sources discovered in the Galactic Center Region (GCR) are of great importance for understanding the evolutionary history of compact objects, accreting binaries and the inner Galaxy. We have identified 10 periodic X-ray sources and 11 candidates out of 843 X-ray sources (net counts>=50) discovered in the 1 Ms Chandra/ACIS-I exposure of the low extinction "Limiting Window" field 1.4 deg south of the Galactic Center. Their period distribution, hard X-ray spectra, and high X-ray-to-optical flux ratios are typical of magnetic cataclysmic variables (MCVs), resembling those of the periodic sources found in the Sgr A* field. When inspected in the detail, however, their properties appear to fit better with a rare sub-class of MCVs, near synchronous MCVs, which is sometimes considered a missing link in the evolution of MCVs from intermediate polars to polars. Our simulations for completeness for discovery of such sources, with periods in the range ~150 - 10^4 sec, suggest that 20-30% of the hard X-ray sources in the LW field (and probably Sgr A*) with significant low energy absorption (and thus located in the GCR) are periodic, implying a large population of MCVs in the Bulge. 108.03 A Catalog of Near-Infrared Variables in the Galactic Center Region Mathieu Servillat1, J. E. Grindlay1, J. Hong1, P. Zhao1, M. van den Berg2, B. Allen1 1Harvard-Smithsonian Center for Astrophysics, 2Utrecht University, Netherlands. 10:30 AM - 10:40 AM Gloucester More than 3000 low-luminosity X-ray sources (10^30-10^33 erg/s at 8 kpc) have been detected in a 17'x17' region around Sgr A*. The detail of their nature, which is still elusive, would bring new insights in the evolutionary history of accreting compact binaries and of the inner Galaxy. The high extinction towards the Galactic Center (Av>25) and the high stellar density are the main obstacles in the characterization of these X-ray sources. We searched for near-infrared long term variables in the Galactic Center Region (GCR). We performed multi-epoch observations in the K-band using large ground-based telescopes. With ISPI (CTIO 4m), we observed every year in 2005-2009 a 10'x10' field down to the crowding limit (seeing of ∼0.8", K∼14). With PANIC (Magellan 6.5m), we obtained 3 sets of observations (2004, 2007, 2010) to map a similar region with higher angular resolution (seeing of 0.4-0.6", K∼15). The preliminary analysis revealed ∼100 K-band variables in the ISPI dataset and ∼600 variables from the PANIC images. About 50 variables are common to both lists. We estimated a boresight correction and constrained the accuracy of the astrometry to typical errors of 1.5" at 95%. We found a significant association of ∼10 of the ISPI variables (which generally show higher amplitude variation than the PANIC variables) with hard X-ray sources in the GCR. We detect a PANIC variable star (K=13.6, dK=0.4) aligned with the low mass X-ray binary AX J1745.6-2901. Another long term variable X-ray source is aligned with a PANIC variable that peaked at K=12.6 in 2007 then disappeared in 2010. This variability is reminiscent of accreting compact binaries and shows the efficiency of an X-ray and K-band transient monitoring in order to constrain the nature of the population of X-ray sources in the Bulge. 108.04 Relativity and the Galactic-center stars Prasenjit Saha1, R. Angélil1 1University of Zurich, Switzerland. 10:00 AM - 10:10 AM Gloucester Galactic-center stars such as S2 reach speeds of a few percent of light at closest approach to the black hole. Hence relativistic effects are potentially observable. The redshift of a star during pericenter passage is especially sensitive to relativity. The same applies to pulsar timing, if a pulsar in that region is discovered. In this work we explain how the equivalence principle, space curvature and frame dragging in principle reveal themselves through the redshift, and discuss possible strategies for disentangling these from the Newtonian perturbations of other mass in the Galactic-center region. 108.05 Constraining the Stellar Mass Function in the Galactic Center Via Mass Loss from Stellar Collisions Douglas Rubin1, A. Loeb1 1Harvard University. 10:40 AM - 10:50 AM Gloucester The dense concentration of stars and high velocity dispersions in the Galactic centre imply that stellar collisions frequently occur. Stellar collisions could therefore result in significant mass loss rates. We calculate the amount of stellar mass lost due to indirect and direct stellar collisions and find its dependence on the present-day mass function of stars. We find that the total mass loss rate in the Galactic centre due to stellar collisions is sensitive to the present-day mass function adopted. We use the observed x-ray luminosity in the Galactic centre to preclude any present-day mass functions that result in mass loss rates > 10^-5 M_sun yr^-1 in the vicinity of ~ 1''. For present-day mass functions of the form, dN/dM prop M^-alpha, we constrain the present-day mass function to have a minimum stellar mass less than about 7 M_sun and a power law slope greater than about 1.25. 108.06 Herschel/HIFI Observations Of The Galactic Center’s Molecular World* Paule Sonnentrucker1, D. A. Neufeld2, M. Gerin3, T. G. Phillips4, PRISMAS team 1Space Telescope Science Institute, 2JHU, 3LERMA, France, 4Caltech. 10:50 AM - 11:00 AM Gloucester Because of its unique thermo-chemistry, fluorine is the only atom in the periodic table that can react exothermically with H2 to form a hydride. An implication of this is that HF will be the dominant reservoir of fluorine wherever the interstellar H2/atomic H ratio exceeds ~1 (Neufeld, Wolfire & Schilke 2005; Neufeld & Wolfire 2009). The recent detections of strong HF absorptions toward a large number of Herschel sources indicate that HF is ubiquitous in the diffuse interstellar medium and that HF can be used as a valuable surrogate tracer of molecular hydrogen, as predicted. In this work we present new Herschel/HIFI observations of the gas clouds associated with the +50 km/s Giant Molecular Cloud (GMC), a cloud complex located nearby Sgr A at the Galactic Center. Absorptions from HF, para-water and CH are detected over velocities ranging from about -185 km/s to +80 km/s. Our spectra exhibit a bi-modal distribution where the HF optical depth is larger than that of para-water by at least a factor of 2 for velocities greater than -80 km/s, as found for other Galactic sources. However, for velocities lower than -80 km/s, the HF optical depth is smaller than that of para-water by factors of 2 to 3. The implications of these differences are reviewed in this paper. *Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. 108.07D Investigating The Star Formation Mode And History Within The Galactic Center (gc) Hui Dong1, D. Wang1, A. Cotera2, S. Stolovy3, M. R. Morris4, J. Mauerhan3, E. A. Mills4, G. Schneider5, D. Calzetti1, C. C. Lang6 1University of Massachusetts, Amherst, 2SETI Institute, 3Spitzer Science Center, California Institute of Technology, 4University of California, Los Angeles, 5Steward Observatory, University of Arizona, 6University of Iowa. 11:00 AM - 11:20 AM Gloucester Star formation in galactic nuclear is believed to be an important component of the ‘duty-cycle’ process in the theory of galaxy formation and evolution. However, the detailed mechanism of star formation activities within these extreme environments is still unclear. As the closest galactic nucleus, the center of our Milky Way is considered to be the best lab to study the star formation mode and history around a supermassive black hole. In this talk, I will present our HST/NICMOS Palpha survey of the Galactic Center, which maps the central 90*35 pc^2 with two narrow-band filters (F187N and F190N). The main products of our survey are a Palpha mosaic of the GC, a extinction map with the highest resolution to date and ~0.6 million stars. ~150 sources with extra emission in 1.87 micron have been identified. Considering their broad-band colors, while ~10 could be foreground stars, most of them should be within the GC and are evolved massive stars with strong stellar wind. We empirically divide these sources into three groups, WN, WC and O If supergiants, according to their equivalent width in 1.87 micron and their intrinsic continuum intensity in 1.90 micron. We suggest that we identify nearly all of the WN stars within the GC and most of the WC stars, except for the ones which are embedded deeply within interstellar dust. One half of these sources are outside three young massive compact star clusters and distribute in isolation/small groups, representing local low-intensity star formation processes or dissolved old massive star clusters, due to the strong tidal force. The intrinsic luminosity distribution of these ~150 sources suggests that there could be a continuous star formation process during the past 10 Myr. 108.08 Spectroscopic Identification of Massive Young Stellar Objects in the Galactic Center Solange Ramirez1, D. An2, K. Sellgren3, R. G. Arendt4, A. Boogert5, T. P. Robitaille6, M. Schultheis7, A. Cotera8, H. A. Smith6, S. R. Stolovy9 1NExScI/Caltech, 2Ewha Womans University, Korea, Republic of, 3The Ohio State University, 4NASA/Goddard Space Flight Center, 5NHSC/Caltech, 6Harvard-Smithsonian Center for Astrophysics, 7Observatoire de Besancon, France, 8SETI Institute, 9SSC/Caltech. 11:20 AM - 11:30 AM Gloucester We present results from our spectroscopic study, using the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope, designed to identify massive young stellar objects (YSOs) in the Galactic Center (GC). Our sample of 107 YSO candidates was selected based on IRAC colors from the high spatial resolution, high sensitivity Spitzer/IRAC images of the central ~300 pc of the Milky Way Galaxy. We obtained IRS spectra over 5 um to 35 um using both high- and low-resolution IRS modules. We spectroscopically identify massive YSOs by the presence of a 15.4 um shoulder on the absorption profile of 15um CO2 ice, suggestive of CO2 ice mixed with CH3OH ice on grains. This 15.4 um shoulder is clearly observed in 16 sources and possibly observed in an additional 19 sources. We show that 9 massive YSOs also reveal molecular gas-phase absorption from CO2, C2H2, and/or HCN, which traces warm and dense gas in YSOs. Our results provide the first infrared spectroscopic census of the massive YSO population in the GC. Monday, May 23, 2011, 11:40 AM - 12:30 PM 109 Stars, Planets and The Weather: If You Don't Like It Wait 5 Billion Years Invited Session America Ballroom 109.01 Stars, Planets and The Weather: If You Don't Like It Wait 5 Billion Years Jeremy J. Drake1 1Harvard-Smithsonian, CfA. 11:40 AM - 12:30 PM America Ballroom Over the last decade realisation has grown that high-energy phenomena such as X-ray and EUV radiation, winds and coronal mass ejections exhibited by stars like our own Sun have an importance way beyond local "stellar weather". From the stormy magnetic extremes of stellar youth to the gentle breeze of stellar middle age and beyond, I describe how stellar weather is now central to problems as diverse as the evolution of supernova Type 1a progenitor candidates, planet formation, and the development and survival of life on planetary systems. Monday, May 23, 2011, 2:00 PM - 3:30 PM 110 12-Years of Science with Chandra: The X-ray Life of Stars Meeting-in-a-Meeting America North 110.01 The X-ray Life of Stars Manuel Guedel1 1University of Vienna, Austria. 2:00 PM - 2:30 PM America North X-rays accompany most phases of star formation and stellar evolution, revealing unexpected diversity and offering unequaled access to high-energy physical mechanisms in stellar environments. X-ray radiation is a foremost diagnostic for magnetic fields and hot, coronal plasma in cool and pre-main sequence stars; X-ray spectroscopy has been used to study composition and compositional anomalies in cool stars as well as densities of coronal sources, including giant flares. However, Chandra has also contributed to the discovery and characterization of X-ray sources related to accretion and outflow processes in young stars. Specifically, magnetospheric accretion is held responsible for an excess of cool plasma and dense X-ray sources probably related to shock heating in the accretion streams. X-ray sources have also been found both in Herbig-Haro objects and in jets very close to T Tauri stars and protostars. In both cases, shocks developing at the interface with the interstellar medium or within the jet flows, perhaps even in the acceleration and collimation region, may be at the origin of the efficient heating although magnetic heating processes may be a viable alternative. Moving toward more massive pre-main sequence stars, energetic processes could also be related to magnetically confined wind shocks. I will discuss these subjects in the context of Chandra findings, concentrating on low- and intermediate mass stars. 110.02 Shaping Outflows from Evolved Stars: Secrets Revealed by Chandra Joel H. Kastner1 1RIT Center for Imaging Science. 2:30 PM - 2:45 PM America North Planetary nebulae (PNe), the near-endpoints of stellar evolution for intermediate-mass stars, exhibit a dizzying variety of optical/near-infrared morphologies: round; elliptical; bipolar; highly point-symmetric; chaotic and clumpy. The physical mechanisms responsible for this morphological menagerie are hotly debated. It is thought that the shape of a PN results from the sculpting of previously ejected, slow-moving (red giant) stellar envelope material by a fast wind from a (newly unveiled) white dwarf at the PN's core. But to explain the large fraction of nonspherical PNe -- which are presumably shaped by aspherical fast winds -- some models now further propose that many (perhaps most) PNe are the products of interacting binary systems. Chandra is yielding valuable insight into these stellar outflow shaping processes. Chandra imaging spectroscopy of PNe provides a unique means to determine the X-ray surface brightness distributions, temperatures, emission measures, and elemental abundances within the "hot bubbles" generated by fast wind shocks. Chandra observations of PNe have also revealed intriguing examples of unresolved X-ray sources that are too hard to be modeled as photospheric emission from hot white dwarfs. Such hard X-ray point sources are likely indicative of the presence of binary companions and/or accretion processes at PN central stars. I summarize the progress in these areas resulting from Chandra's first dozen years, and present early results from the first systematic Chandra survey of PNe in the solar neighborhood -- a survey designed to understand the formation and evolution of hot bubbles, and to establish the frequency and characteristics of point-like X-ray sources, within PNe with names like the Ring, the Dumbbell, the Owl, and Saturn. This work is supported by NASA Astrophysics Data Analysis Program and Chandra X-ray Center (CXC) grants to RIT. The CXC is operated by SAO for and on behalf of NASA under contract NAS8-03060. 110.03 Swanning around with Chandra: star and planet formation in Cygnus OB2 Jeremy J. Drake1 1Harvard-Smithsonian, CfA. 2:45 PM - 3:00 PM America North Understanding massive "starburst" clusters is crucial for the first stars, starburst galaxies, galactic nucleosynthesis, evolution and ISM mixing, and star and planet formation on universal and Galactic scales. Recent awareness that the 2 Myr old cluster Cygnus OB2, at only 1.5kpc, has supercluster characteristics, motivated a Chandra VLP survey of the region as part of a large multiwavelength legacy effort exploiting its proximity to learn about starburst astrophysics. I will present the first results from the ongoing analysis of the survey that was completed a year ago. About 10,000 stars down to 0.5 solar masses have been detected, proving the most complete census of a massive star forming region ever obtained and large star samples with which to test theories of giant molecular cloud collapse, massive star formation and protoplanetary disk evolution. 110.04 X-ray Line Diagnostics of Shocked Outflows in Eta Carinae and Other Massive Stars Michael F. Corcoran1 1USRA. 3:00 PM - 3:30 PM America North Strong stellar winds in massive stars generate high energy thermal X-ray emission largely via radiative line driven instability and through wind-wind collisions in binary and multiple star systems. These X-rays are sensitive to key wind properties (mass loss rate, the wind acceleration law, wind clumping). X-ray emission line profiles provide important diagnostics of these properties and have helped shape our understanding of wind-driven mass loss in significant and surprising ways. I review some of the major results obtained from high resolution X-ray spectrometry for a selection of massive stars, and discuss how future observations will advance our understanding of hot star mass loss. 111 Nuclear Physics I – Stellar Nucleosynthesis Meeting-in-a-Meeting St. George CD 111.01 The Nuclear Physics of Hydrogen Burning in Stars Peter D. Parker1 1Yale University. 2:00 PM - 2:30 PM St. George CD A review of the present status of stellar hydrogen-burning reaction rates with emphasis on the most uncertain of the important rates - what is currently being measured and what needs to be done. 111.02 Underground Accelerators for Precise Nuclear Physics: LUNA and DIANA Daniela Leitner1 1Michigan State University. 2:30 PM - 3:00 PM St. George CD Current stellar model simulations are at a level of precision that uncertainties in the nuclear-reaction rates are becoming significant for theoretical predictions and for the analysis of observational signatures. To address several open questions in cosmology, astrophysics, and non-Standard-Model neutrino physics, new high precision measurements of direct-capture nuclear fusion cross sections will be essential. At these low energies, fusion cross sections decrease exponentially with energy and are expected to approach femtobarn levels or less. The experimental difficulties in determining the low-energy cross sections are caused by large background rates associated with cosmic ray-induced reactions, background from natural radioactivity in the laboratory environment, and the beam-induced background on target impurities. Natural background can be reduced by careful shielding of the target and detector environment, and beam-induced background can be reduced by active shielding techniques through event identification, but it is difficult to reduce the background component from cosmic ray muons. An underground location has the advantage that the cosmic ray-induced background is reduced by several orders of magnitude, allowing the measurements to be pushed to far lower energies than feasible above ground. This has been clearly demonstrated at LUNA by the successful studies of critical reactions in the pp-chains and first reaction studies in the CNO cycles. The DIANA project (Dakota Ion Accelerators for Nuclear Astrophysics) is a collaboration between the University of Notre Dame, Michigan State University, Colorado School of Mines, Regis University, University of North Carolina, Western Michigan University, and Lawrence Berkeley National Laboratory, to build a nuclear astrophysics accelerator facility deep underground. The DIANA accelerator facility is being designed to achieve large laboratory reaction rates by delivering two orders of magnitude higher ion beams to a high density, super-sonic jet-gas target. The conceptual design of the DIANA accelerator facility and the status of the facility is presented. 111.03 Status and Plans for Measurements of the 12C(α,γ)16O Reaction Ernst Rehm1 1Argonne National Laboratory. 3:00 PM - 3:30 PM St. George CD Carbon and oxygen are two important elements for the existence of live on our planet. While the reaction paths for producing these two elements in stars are well known their cross sections in stellar environments still have considerable uncertainties. I will discuss the status of measuring the 12C(α,γ)16O Reaction in the laboratory and report on some new attempts utilizing bubble chambers developed for dark matter searches. This work was supported by the US Department of Energy, Office of Nuclear Physics, under contract DE-AC02-06CH11357. 112 Searching for Exoplanets with Kepler Meeting-in-a-Meeting America South 112.01 The Status of Kepler's Search for Earth-size Planets Natalie M. Batalha1, Kepler Team 1San Jose State University. 2:00 PM - 2:15 PM America South NASA's Kepler Mission uses transit photometry to determine the frequency of earth-size planets in or near the habitable zone of Sun-like stars. The photometer is a 0.95-m effective aperture, wide field of view Schmidt camera in an Earth-trailing orbit that monitors over 150,000 stars brighter than 16th magnitude in a 115 square degree field of view. The mission has had two major public data releases, providing the astronomical community with four months of nearly continuous, high-precision photometry of all stars targeted as part of the Kepler planet search. A catalog of approximately 1,000 stars with transiting planet candidates -- more than 70% of which are smaller than Neptune -- accompanied the data release (Borucki et al. 2011). As Kepler collects more data, it gains sensitivity to smaller planets at longer orbital periods. This is reflected in the catalog as it contains sizable numbers of candidates that are earth-sized as well as sizable numbers of candidates in the habitable zone. Multiple transit systems are abundant in the released data. Dynamical studies suggest that the false-positive rate for these systems will be smaller than for the general sample. Moreover, the potential for determining planet masses via transit timing variations hold much promise for confirming the smaller planet candidates. Ground-based follow-up observations, transit timing observations, and blend analyses to rule out false positives have all played a major role in establishing the planet interpretation, leading to major mission milestones such as the discovery of Kepler's first rocky planet, Kepler-10b, and the discovery of six transiting planets orbiting the same star, Kepler-11. We present an overview of the status of the mission -- its health, performance, discoveries to date, our progress in determining the frequencies of planets, and our strategies moving forward. Funding for this mission is provided by the NASA Science Mission Directorate. 112.02 Radii, Masses, Densities, and Occurrence for Planets within 0.25 AU Geoffrey W. Marcy1, A. Howard1, Kepler Team 1UC, Berkeley. 2:15 PM - 2:30 PM America South We report the observed distribution of planet radii, masses, and orbital distances for orbital periods less than 50 days around Solar-type (GK) stars.  We draw from extensive Doppler and Kepler measurements that offer good completeness for planets with radii as small as 2.0 Earth-radii.  We include the photometric signal-to-noise ratio for all 156,000 target stars to determine planet detectability as a function of planet radius and orbital period for each target.  We consider Kepler target stars within the ``Solar subset'' having Teff = 4100--6100 K, logg = 4.0--4.9, and stars brighter than Kepler magnitude 15.    The resulting occurrence of planets as a function of planet radius and orbital period increases strongly toward the smallest radii (2 Earth-radii) and toward longer orbital periods ( up to 50 days, 0.25 AU). Summing over all orbital periods (P<50 d), the distribution of planet radii increases rapidly with smaller planet size.  This high occurrence of smaller planets supports core-accretion theory but disagrees with the theory of migration in a gaseous disk that predicts a desert at Super-Earth and Neptune sizes for close-in orbits, which is not seen.  Planets with orbital periods less than 2 days are extremely rare. We explore the densities of exoplanets by finding self-consistent mappings from the distributions of planet radius (from Kepler) to mass (from Doppler). 112.03 Confirming Kepler Planets with Rossiter-McLaughlin Observations William D. Cochran1, Kepler Science Team 1Univ. of Texas, Austin. 2:30 PM - 2:40 PM America South The Rossiter-McLaughlin (RM) effect causes a transiting planet to perturb the spectral line shape of stellar photospheric lines. This perturbation is generally interpreted as a anomalous Doppler shift of the stellar lines during transit, and the time profile of this shift is highly diagnostic of the projected inclination of the stellar orbital angular momentum vector to the stellar rotational angular momentum. This method was used to help confirm Kepler-8b (Jenkins et al. 2010 ApJ 724 1108). For the case of very rapid stellar rotation, the RM effect is manifested by a bump moving across the rotationally broadened stellar line profile. Since such a bump is not easily interpreted as an anomalous Doppler shift, instead Doppler Tomography techniques offer the possibility of confirming planets orbiting these rapidly rotating stars. This is a valuable new tool, as these stars are rotating too rapidly for standard high precision radial velocity measurements to confirm the existence of planets by the standard measurement of the stellar Doppler reflex motion. We will also explore the possibility of using Rossiter-McLaughlin data during transits to confirm the existence of very small planets that would give Doppler reflex wobbles during their orbits that are too small to measure with current RV precision. 112.04 Confirming Kepler Planets via Transit Timing Variations Matthew J. Holman1, Kepler Science Team 1Harvard-Smithsonian, CfA. 2:40 PM - 2:55 PM America South The analysis of transit timing variations has proven to be a successful method for confirming that some candidate systems are indeed composed of planets. For some systems, such as Kepler-9, the addition of radial velocity observations or future Kepler photometry is required to determine the planetary masses. For other systems, such as Kepler-11, the masses of a number of planets can be measured from the transit times alone. We review the process of using transit timing variations to confirm Kepler planets, including an estimate of the number of planets we expect to confirm with this technique. In particular, we discuss the prospects of confirming Kepler planets in the habitable zones of their host stars. 112.05 High Resolution Imaging of Kepler Objects of Interest (KOI) Andrea K. Dupree1, E. Adams1, D. R. Ciardi2, T. N. Gautier, III3, S. Howell4, C. Kulesa5, D. McCarthy5, Kepler Science Team 1SAO/CfA, 2IPAC/Caltech, 3JPL/Caltech, 4NASA/ARC, 5U. of AZ. 2:55 PM - 3:05 PM America South The spatial resolution of the Kepler telescope is designed to be 4 arcsec (~1 pixel) which could allow background stars to contribute to the light of a Kepler target. Thus an observed transit might be a false positive due to a background eclipsing binary. In addition, dilution of the transit signal by a background star can severely compromise the parameters derived for a planet candidate. The Kepler Follow on Program (KFOP) includes high resolution images of the KOI targets, obtained principally at the following facilities: speckle imaging in V and R with the two-color speckle camera on the 3.5m WIYN telescope; Adaptive Optics imaging in J band and Ks with the PHARO near-infrared camera on the 200-in Hale Telescope; Adaptive Optics imaging in J and Ks band with the ARIES camera on the 6.5m MMT Telescope; AO imaging in J band and Ks with IRCAL on the 3-m telescope at Lick Observatory. Results from the follow up observations will be shown as well as the implications for the derivation of planetary characteristics. High spatial resolution images are a key part of the follow-up program for high-confidence level acceptance for Earth and super Earth-size planets. 112.06 Validation of Planet Candidates without Dynamical Confirmation Guillermo Torres1, F. Fressin1, J. J. Lissauer2, G. W. Marcy3, R. L. Gilliland4, C. E. Henze5, Kepler Science Team 1Harvard-Smithsonian CfA, 2NASA Ames Research Center, 3University of California, 4STScI, 5NASA Ames Research Center (NAS). 3:05 PM - 3:20 PM America South Confirmation of candidate transiting planets is usually achieved by spectroscopic means, with the detection of the reflex motion of the star, a line bisector analysis, or observation of the Rossiter-McLaughlin effect. Many of the most interesting candidate transiting planets identified by the Kepler Mission cannot be confirmed in this way, including Earth- or super-Earth-size planets in the habitable zone of their parent stars. The planetary masses are so small, and/or the orbital periods so long, that their Doppler signal is undetectable with current instrumentation. Additionally, the stars may be too faint, too chromospherically active, or rotating too rapidly for precise radial-velocity measurements. Transit timing variations in multiple systems may also be so small as to be unmeasurable in many cases. Lacking these methods of dynamical confirmation, the Kepler team has developed ways of "validating" candidates by modeling the photometry to place constraints on the wide range of false positives ("blends") that can mimic the transit light curves, including background eclipsing binaries and hierarchical triple systems. This presentation will describe this modeling, and how it is combined with complementary constraints from follow-up observations and centroid motion analysis to estimate the frequency of blends, and ultimately the probability that a candidate is a bona-fide planet. Funding for this Discovery mission is provided by NASA's Science Mission Directorate. 112.07 Determining The Detection Completeness Of The Kepler Pipeline Jessie Christiansen1, T. N. Gautier2, W. J. Borucki3, S. T. Bryson1, D. Caldwell1, D. Charbonneau4, D. Ciardi5, E. B. Ford6, M. R. Haas3, S. B. Howell3, J. M. Jenkins1, J. Kolodziejcak7, A. Prsa8, J. F. Rowe1 1NASA Ames Research Center/SETI Institute, 2Jet Propulsion Laboratory, Calif. Institute of Technology, 3NASA Ames Research Center, 4Harvard-Smithsonian Center for Astrophysics, 5Exoplanet Science Institute, Calif. Institute of Technology, 6University of Florida, 7MSFC, 8Villanova University. 3:20 PM - 3:30 PM America South We describe an initial study into characterizing the completeness of the Kepler data reduction pipeline with respect to detecting transiting planets. The primary goal is to determine the transit detectability for a given set of planet radii and orbital periods of interest for a subset of the Kepler light curves covering a grid of stellar parameter space. We use a Monte Carlo approach, injecting signals from the putative planets at the pixel level, and processing the pixels through the same pipeline as the science pixels. By mapping an input population of planets to an output set of candidates, we can approximate a posteriori the real planet population. 113 Early Science From Pan-STARRS 1 Special Session Staffordshire 113.01 The First year of the Pan-STARRS 1 System: Surveys, Cadences, Data Products, and Performance Kenneth C. Chambers1 1Univ. of Hawaii. 2:00 PM - 2:05 PM Staffordshire PS1, the Pan-STARRS Telescope No. 1 began the PS1 Science Mission May 13, 2009. Operations of the PS1 System include the Observatory, Telescope, 1.4 Gigapixel Camera, Image Processing Pipeline , PSPS relational database and reduced science product software servers. The PS1 Surveys include: (1) A 3pi Steradian Survey, (2) A Medium Deep survey of 11PS1 footprints spaced around the sky; (3) A solar system survey optimized for Near Earth Objects, (4) a Stellar Transit Survey; and (5) a Deep Survey of M31. The PS1 3pi Survey has covered the sky with 4 to 6 visits above a declination of -30 in five bands. The performance of the PS1 system, sky coverage, cadence, and data quality of the surveys will be presented as well as plans for the transient data release to the community. The PS1 Science Consortium consists of The Institute for Astronomy at the University of Hawai'i in Manoa, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, the University of Durham, the University of Edinburgh, the Queen's University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Los Cumbres Observatory Global Telescope Network Incorporated, and the National Central University of Taiwan, and NASA. 113.02 The Pan-STARRS-1 Inner Solar System Key Project Larry Denneau, Jr.1 1IfA, Hawaii. 2:05 PM - 2:10 PM Staffordshire We will present a summary of PS1 inner solar system (ISS) processing and resultant data from the first year of telescope operations, including main-belt asteroids discovered and detected, near-earth asteroids (NEAs) and potentially hazardous asteroids (PHAs) discovered, and other objects and classes of interest. We will describe difficulties and progress in general asteroid processing of PS1 transient catalogs and refinements to data processing to mitigate problems. Finally, we will briefly discuss ongoing research within the PS1 Science Consortium in the size-frequency distribution of main-belt comets (MBCs), close-approach monitoring and mass estimation of main-belt asteroids (MBAs), cross-recovery of PS1-detected Jupiter Trojans with WISE spacecraft data, and the outlook for future PS1 ISS science from year two of PS1 operations. 113.03 The Pan-STARRS-1 Outer Solar System Key Project Matthew J. Holman1, P. Protopapas1, Y. Chen2, H. Lin2, T. Grav3, D. Ragozzine1, Pan-STARRS-1 Science Consortium 1Harvard-Smithsonian, CfA, 2National Central University, Taiwan, 3Johns Hopkins University. 2:10 PM - 2:15 PM Staffordshire The Pan-STARRS-1 survey began full scale scientific operation in May, 2010. Roughly 60% of the observing time of the Pan-STARR-1 telescope is dedicated to a survey with an observing cadence that is suitable for the detection of slow-moving solar system bodies. We have developed an independent software pipeline that is optimized for the detection of such bodies at and beyond the distance of Jupiter. With this pipeline, the Pan-STARRS-1 survey will yield an essentially complete census of outer solar system bodies (Centaurs,comets, and trans-neptunian objects) brighter than magnitude r=22 to r=22.5. We present an update on the results of this survey and the outer solar system investigations it has enabled. 113.04 Results from the Pan-Planets Observing Campaign 2010 Johannes Koppenhofer1, T. Henning2 1MPE, Germany, 2MPIA, Germany. 2:15 PM - 2:20 PM Staffordshire The Pan-STARRS1 Planet Survey (Pan-Planets) is a search for transiting extra-solar planets in the Galactic disk. The large field of view of the Pan-STARRS1 camera enables us to monitor more than 200.000 stars in three fields with a photometric precision better than 1%. We give a description of the goals of Pan-Planets and present some early results from the first observing campaign in 2010. 113.05 Mapping the Local Group with Pan-STARRS Nicolas Martin1 1MPIA, Germany. 2:20 PM - 2:25 PM Staffordshire Pan-STARRS has now been systematically surveying the northern sky for a year and has already provided a mapping of three quarters of the Milky Way sky. With its five filters (grizy) it will, within the three years of the mission, provide an unprecedented map of the Local Group and its satellite system, probing a volume 25 times larger than that probed by the Sloan Digital Sky Survey. I will review the Local Group science that is being performed with the survey data and, in particular, report on our on-going search for unknown faint Local Group dwarf galaxies and stellar streams. 113.06 PS1 Photometric Ubercalibration: Improved Stellar Colors for Measuring Reddening Douglas P. Finkbeiner1, M. Juric1, E. F. Schlafly1 1Harvard University. 2:25 PM - 2:30 PM Staffordshire Accurate stellar colors are necessary for a wide range of PS1 science objectives. I will report on the status of our PS1 "ubercalibration" effort to provide improved photometric calibration over the entire 3 pi survey footprint. As an example, I will show how this new calibration improves dust reddening measurements using the "bluetip" method. 113.07 Pan-STARRS1 Medium Deep Fields John L. Tonry1 1Univ. of Hawaii. 2:30 PM - 2:35 PM Staffordshire Pan-STARRS1 has observed eleven 8 sq. deg. fields around the sky since April 2009, and has accumulated approximately 200 observations apiece, producing rather deep, grizy images with a rich time history. We will describe results on the hosts of "hostless" type Ia supernovae derived from this imagery. We will also touch on some of the other opportunities afforded by these observations such as determining proper motions and parallax, photometric variability, moving objects, and sources that lie off of the stellar locus. 113.08 Pan-STARRS and Quasars: The Search for z > 5.5 Quasars in Pan-STARRS Eric P. Morganson1 1MPIA, Germany. 2:35 PM - 2:40 PM Staffordshire It has been nearly 10 years since Fan et al. released the first sample of high redshift (5.5 < z < 6.5) quasars found as i dropouts in the Sloan Digital Sky Survey (SDSS). In the intervening decade the sample of high redshift quasars has grown only slowly. Only recently was the first redshift 7 quasar found in the UKIRT Infrared Deep Sky Survey (UKIDSS). With a survey area of 30,000 square degrees, i and z depth superior to SDSS and a y band centered around 1000 nm, Pan-STARRS is poised vastly increase the sample of i dropout (5.5 < z < 6.5) quasars and discover a significant sample of z dropout quasars (6.5 < z < 7.5). We report on the early observations in both of these areas. 113.09 Weak Lensing from Pan-STARRS PS1 Surveys Nick Kaiser1, T. Dixon1 1Univ. of Hawaii. 2:40 PM - 2:45 PM Staffordshire We present forecasts for the density of sources and precision of weak lensing image shear measurements that will be attainable with the PS1 wide and medium deep imaging surveys. We also present first results from stacking of shear signal for known clusters in medium deep fields. 113.10 Cosmological lensing with Pan-STARRS Alan Heavens1 1University of Edinburgh, United Kingdom. 2:45 PM - 2:50 PM Staffordshire With 30,000 square degrees coverage, Pan-STARRS 1 will be the largest optical survey designed to be capable of cosmological studies through weak lensing. I report on the status of the cosmological lensing programme of Pan-STARRS. Although the full power of the project will only be apparent when the survey is complete, I will review the early data and the prospects for science. 113.11 Large Scale Structure with Pan-STARRS Shaun Cole1 1University of Durham, United Kingdom. 2:50 PM - 2:55 PM Staffordshire After 3 years of observations the stacked data from the Pan-STARRS 3pi and Medium Deep Surveys will be a powerful resource for the study of the large scale galaxy distribution. The multi-band, grizy, photometry will provide photometric redshifts for huge samples of galaxies. The MDS will have a median redshift of z=1 and contain over 5 million galaxies. This makes it ideal for studying the evolution of galaxy clustering and dependence of galaxy clustering on galaxy properties (e.g. colour or luminosity). The shallower 3pi survey probes significantly deeper than the SDSS and its coverage (away from the plane of the Galaxy) will be almost 3 times that of SDSS. We expect a catalogue of over 100 million galaxies with a median redshift of 0.5, making it ideal for the study structure on the largest scales and possibly the local detection of the BAO signal. I will present preliminary data from the ongoing analyses, including deep galaxy number counts from the MDS, tests of photometric redshifts, and the first results of cluster finding algorithms run on the multi-colour data. 113.12 Early astrometric results from PS1 David G. Monet1, E. A. Magnier2, M. C. Liu2, N. R. Deacon2 1U.S. Naval Obs., 2Institute for Astronomy, University of Hawaii. 2:55 PM - 3:00 PM Staffordshire The PS1 survey has covered the 3pi area at least once, and a surprisingly large area has been surveyed in multiple colors at many epochs. This enables two exciting areas of early astrometric study. The PS1 positions can be compared with existing positions (SDSS, USNO-B, etc.) to study the distribution of proper motions of a large number (approaching one billion) of stars using the approximately 10 year baseline between PS1 and SDSS and approximately 25 year baseline between PS1 and the second epoch photographic plates. For the areas where PS1 has multiple epochs and multiple colors, the search for stellar parallaxes using only PS1 data can begin. Given the large area covered and the approximately 10-20mas error for each measurement of brighter stars, the search for new objects within 20pc can begin. 113.13 Pan-STARRS-1 Medium Deep Survey: Early Cosmology Results from Type Ia Supernovae Armin Rest1 1Harvard University. 3:00 PM - 3:05 PM Staffordshire The Panoramic Survey Telescope And Rapid Response System-1 (Pan-STARRS-1, PS1) has been in full operation since January 2010. The Medium Deep Survey (MDS) component is allocated 25% of the time to cover 11 fields (7-8 sq. deg. each) typically with significant multi-wavelength overlap from previous surveys (i.e., SDSS, DEEP2, CDFS, COSMOS). The cadence covers the g,r,i,z filters every 3 days (the y filter during bright time) with a nightly depth to sample light curves of Type-Ia supernovae to redshifts greater than 0.5. To date, more than 1300 unique optical transients have been identified in the PS1-MDS, including more than 140 spectroscopically confirmed supernovae. We will present early results and cosmological parameters from the sample thus far of Type-Ia supernovae spanning redshifts from 0.03 to greater than 0.6 and discuss the implications for the following 1.5 years of the survey. 113.14 Surveying the Extended Solar Neighborhood with Pan-STARRS-1 Michael C. Liu1, E. Magnier1, N. Deacon1, B. Goldman2 1Univ. of Hawaii, 2MPIA, Germany. 3:05 PM - 3:10 PM Staffordshire The Pan-STARRS-1 (PS1) optical wide-field telescope has begun a series of multi-band surveys covering the the 30,000 sq. degs. observable from Hawaii, with multi-epoch data to be obtained over the next 3 years. Its unique combination of high quality photometry, astrometry and red sensitivity will yield the most complete survey to date of the extended solar neighborhood, especially through high quality proper motions and parallaxes for the low-luminosity stars and brown dwarfs within 100 pc from Earth, both as isolated objects and in moving groups and open clusters. In addition, the large volume probed by PS1 will enable identification of the rarest classes of ultracool dwarfs. 113.15 PAndromeda - A Dedicated Deep Survey of M31 with Pan-STARRS 1 Arno Riffeser1, S. Seitz1, R. Bender1 1Max Planck Insitute for Extraterrestrial Physics, Germany. 3:10 PM - 3:15 PM Staffordshire PAndromeda monitors M31 for 2% of the overall PS1 time. This corresponds to 0.5 h per night during a period of 5 months per year. PAndromeda is designed to identify gravitational microlensing events, caused by bulge and disk stars (self-lensing) and by compact matter in the halos of M31 and the MW (halo lensing, or lensing by MACHOs). The main science goals of PAndromeda are measuring the masses and mass-fraction of compact objects in the M31 and MW halos, and constraining the M31 bulge mass function at the low mass end. As a side product PAndromeda is also able to search for microlensing events towards M32 and NGC205. The interpretation of the microlensing events requires understanding the mix of stellar ages and metalicities in the bulge, disk, and halo of M31 as obtained from resolved stellar populations (census of supergiants, OB-associations, analysis of CMD diagrams as a function of location), variability studies (Cepheids to LPVs), and color gradients in the light profiles. All these informations can directly extracted from the PAndromeda data itself. During the first season 2010 PAndromeda monitored M31 from end of July 2010 till end of December 2010 on 91 nights (58%). In total 1782 images were exposed, on 90 nights in r' and on 66 in i' band. The total amount of reduced data is 14 TB. From the 2010 season we analyzed the central field of M31 (21'x21'). This is to test the detection process in the field where we expect the highest lensing rate because of self lensing. So far we detected 3 high quality microlensing light-curves. The third one is very bright with 19 mag in r'. Such high flux excess events are more difficult to reconcile with self-lensing than with halo-lensing. The full data set is currently analyzed. 113.16 Pan-STARRS1 Observations of Ultraluminous Supernovae Ryan Chornock1, E. Berger1, L. Chomiuk1, A. Soderberg1, M. Huber2, A. Rest3, R. J. Foley1, G. Narayan1, G. Marion1, R. P. Kirshner1, C. Stubbs1, P. Challis1, A. Riess2, J. Tonry4, S. Smartt5, W. Wood-Vasey6, S. Valenti5, Pan-STARRS1 Builders 1Harvard/CfA, 2Johns Hopkins, 3STScI, 4IfA/Hawaii, 5Queen's, United Kingdom, 6Pitt. 3:15 PM - 3:20 PM Staffordshire We will present observations of several ultraluminous supernovae discovered at high redshifts by the Harvard/Johns Hopkins team in imaging data from the Medium Deep Survey of Pan-STARRS1. These objects have been found at redshifts in the range 0.5-1.4, with peak absolute magnitudes up to M=-23. We will present photometric and spectroscopic observations which exhibit a diversity of behaviors. While some objects appear to resemble the unusual SCP06F6-like transients, others have novel spectra and spectral energy distributions. We will evaluate several proposed explanations for the extreme luminosities of these objects. 114 AAVSO: Variable Stars in the Imaging Era Special Session America Central 114.01 Imaging Variable Stars with HST Margarita Karovska1 1Harvard Smithsonian, CfA. 2:00 PM - 2:18 PM America Central The Hubble Space Telescope (HST) observations of astronomical sources, ranging from objects in our solar system to objects in the early Universe, have revolutionized our knowledge of the Universe its origins and contents.I will highlight results from HST observations of variable stars obtained during the past twenty or so years. Multiwavelength observations of numerous variable stars and stellar systems were obtained using the superb HST imaging capabilities and its unprecedented angular resolution, especially in the UV and optical. The HST provided the first detailed images probing the structure of variable stars including their atmospheres and circumstellar environments. AAVSO observations and light curves have been critical for scheduling of many of these observations and provided important information and context for understanding of the imaging results of many variable sources. I will describe the scientific results from the imaging observations of variable stars including AGBs, Miras, Cepheids, semi-regular variables (including supergiants and giants), YSOs and interacting stellar systems with a variable stellar components. These results have led to an unprecedented understanding of the spatial and temporal characteristics of these objects and their place in the stellar evolutionary chains, and in the larger context of the dynamic evolving Universe. 114.02 Interferometry and the Cepheid Distance Scale Thomas G. Barnes1 1McDonald Observatory. 2:18 PM - 2:36 PM America Central This talk will examine progress on the Cepheid distance scale with particular emphasis on recent developments in techniques that depend on interferometric observations. Specifically I will discuss how interferometry has made possible direct measurements of Cepheid distances through interferometric pulsation distances and surface brightness pulsation distances. These results will be compared to recent trigonometric distances. 114.03 Spots, Eclipses, and Pulsation: The Interplay of Photometry and Optical Interferometric Imaging Brian K. Kloppenborg1 1University of Denver. 2:36 PM - 2:54 PM America Central Present optical/IR interferometers like CHARA are not only capable of probing the environment surrounding stars, but also resolving surface details on the stars themselves. Because of this, interferometers can produce results on the classical topics of photometry: namely pulsation, eclipses, and star spots. In this talk I discuss these three common areas, and how interferometry and photometry can be used in conjunction to yield superior results. This research involves Georgia State University's Center for High Angular Resolution Astronomy (CHARA) in collaboration with the University of Michigan. It is supported in part by AAVSO, the National Science Foundation grant 10-16678 and the bequest of William Hershel Womble in support of astronomy at the University of Denver. 114.04 Variable Stars and The Asymptotic Giant Branch: Stellar Pulsations, Dust Production and Mass Loss Angela Speck1 1Univ. of Missouri. 2:54 PM - 3:12 PM America Central Intermediate-mass stars (0.8-8.0 solar masses) are major contributors of new elements to interstellar space. These stars eventually evolve into asymptotic giant branch (AGB) stars. During the AGB phase, these stars suffer intensive mass loss leading to the formation of circumstellar shells of dust and neutral gas, including the new elements formed during the star’s life. However, the intimate link between dust formation and mass loss from these stars remains inadequately understood. Using a infrared and visible imaging of AGB stars an investigation of the structure and evolution of the circumstellar dust and its environment will be presented. 114.05 Probing Mira atmospheres using optical interferometric techniques Sam Ragland1 1W. M. Keck Observatory. 3:12 PM - 3:30 PM America Central The modern optical interferometric observations of Mira atmospheres are discussed. The earlier near-infrared closure-phase measurements of a sample of Asymptotic Giant Branch (AGB) stars and subsequent imaging observations of a handful of brighter ones show that asymmetry is common in the cool atmospheres of late-type stars. The potential of optical interfermetric observations in conjunction with radio interferometric observations in studying the structure and kinematics of the envelope around Mira stars are highlighted. We explore the use of other interferometric observables such as (1) null-leakage in the mid-infrared, combined with near-infrared squared-visibilities in constraining the temperature structure of the extended atmosphere of Mira stars and (2) differential phase in detecting asymmetry in the molecular and dusty shells of Mira stars. 115 Hard X-ray Surveys of AGN Special Session St. George AB 115.01 INTEGRAL /IBIS Survey of AGN Loredana Bassani1 1INAF IASF-Bologna, Italy. 2:00 PM - 2:20 PM St. George AB We present the sample of AGN detected by INTEGRAL /IBIS in the 20-100 keV band and reported in most recent surveys. The sample contains 268 objects of which 127 are of type 1, 115 are of type 2 and 23 are Blazars ; it also includes some peculiar class of AGN detected at high energies for the first time such as few XBONG, a number of Liners and a small set of type 2 QSO. The absorption properties of the sample are discussed including an update on the fraction of Compton thick objects. For a sub-sample of 87 sources, which represent a complete set of bright AGN , we study the hard X-ray (20-100keV) spectral properties also in comparison with SWIFT/BAT 58 months data; we give information on spectral and flux variability , average spectral shape and BAT/IBIS cross calibration constant. For this complete sample we also present broad band data for Sey1 and Sey2 separately. In particular, for Sey1 we define the parameter space of photon index versus cut-off energy assuming fixed values of the reflection: this exercise provides strong constraints on both parameters which can be used as key inputs for modelling of AGN and for estimating their contribution to the cosmic background radiation. For Sey2 instead, broad band study shows strong evidence that a single uniform absorbing medium does not account for the observed spectra. In particular the Compton reflection components we measure, reflection continuum and iron line(s), are not immediately compatible with a scenario in which the absorbing and reflecting media are one and the same, i.e. the obscuring torus. We also present for the first time the broad band (01.-100 keV) properties of a sample of 14 hard X-ray selected narrow Line Sey1 and their relation to the accretion parameters. An update on our optical and radio follow up work will also be presented as well as an insight into the cross correlation analysis with gamma-ray catalogues. Future prospects will finally be outlined. 115.02 Complete Hard X-ray Surveys, AGN Luminosity Functions and the X-ray Background Jack Tueller1 1NASA/GSFC. 2:20 PM - 2:40 PM St. George AB AGN are believed to make up most of the Cosmic X-Ray Background (CXB) above a few keV, but this background cannot be fully resolved at energies <10 keV due to absorption. The Swift/BAT and INTEGRAL missions are performing the first complete hard x-ray surveys with minimal bias due to absorption. The most recent results for both missions will be presented. Although the fraction of the CXB resolved by these surveys is small, it is possible to derive unbiased number counts and luminosity functions for AGN in the local universe. The survey energy range from 15-150 keV contains the important reflection and cutoff spectral features dominate the shape of the AGN contribution to the CXB. Average spectral characteristics of survey detected AGN will be presented and compared with model distributions. The numbers of hard x-ray blazars detected in these surveys are finally sufficient to estimate this important component's contribution the cosmic background. Constraints on CXB models and their significance will be discussed. 115.03 Unification of AGN at hard X-rays Volker Beckmann1 1APC, Francois Arago Centre, France. 2:40 PM - 3:00 PM St. George AB Unified models of Active Galactic Nuclei (AGN) address the question whether or not the different types of AGN can be explained by the same intrinsic mechanism, altered only by external effects such as orientation to or absorption in the line of sight, or by the presence/absence of beamed emission. Hard X-ray spectra give the opportunity to investigate AGN in an energy range where absorption has little effect on the observed spectrum. Thus, in case different AGN types are intrinsically the same, their average hard X-ray spectra should be similar. Swift and INTEGRAL provide hard X-ray spectra of hundreds of AGN. Seyfert 1 and Seyfert 2 galaxies seem to show the same intrinsic spectra with photon index 1.9 and a reflection component of R=1. At the same time it appears that more luminous AGN are rather type 1 than of type 2 and that the unabsorbed sources dominate at high luminosities. A closer look at the brightest AGN, like Cen A and NGC 4151, adds more complications though. NGC 4151 data reveil a complex geometry, and the X-ray spectrum of Cen A leaves room for a non-thermal as well as for a thermal interpretation. We will discuss the current status of the unified model of AGN in view of the latest results on hard X-ray spectra and their connection to the gamma-rays as observed by Fermi/LAT and Cherenkov telescopes such as HESS, MAGIC, and VERITAS. 115.04 Results from Multi-wavelength Follow-ups of Hard X-ray Selected Samples Lisa M. Winter1 1CASA/University of Colorado-Boulder. 3:00 PM - 3:20 PM St. George AB Supermassive black holes reside at the centers of most massive galaxies. Among these, only 10-20% actively accrete matter, emitting powerful amounts of energy across the full electromagnetic spectrum. Many questions about the nature of AGN remain, such as what are the properties of these sources, what activates accretion, and how do AGN influence their host galaxies. In order to answer these questions, it is imperative to select an unbiased sample of AGN. Very hard X-ray selection is ideal since AGN directly emit their energy in this band and the emission is powerful enough to cut through much of the dust and gas that obscures the AGN signature in softer wave bands. In this talk, we highlight the results of multi-wavelength follow-ups of nearby AGN selected through the Swift Burst Alert Telescope survey. We present results from X-ray, optical, and infrared spectroscopy. We compare various methods of determining the bolometric luminosity, including X-ray, optical [O III] 5007 Angstrom emission, and mid-IR emission lines measured from high-resolution Spitzer observations. We also compare the luminosity measurements between Seyfert 1s and 2s and show that these distributions fit well in the unified AGN model. Among the new results from imaging follow-ups on the host galaxies, we show the host galaxies of the very hard X-ray selected AGN are mostly spirals and peculiars with a high rate of mergers. This suggests that mergers are triggering the active accretion phase in nearby AGN. 116 Astronomy Unexpected! Innovative Strategies for Reaching Non-Traditional Students Special Session Gloucester 116.01 Making Astronomy Accessible Noreen A. Grice1 1You Can Do Astronomy, LLC. 2:00 PM - 2:18 PM Gloucester A new semester begins, and your students enter the classroom for the first time. You notice a student sitting in a wheelchair or walking with assistance from a cane. Maybe you see a student with a guide dog or carrying a Braille computer. Another student gestures “hello” but then continues hand motions, and you realize the person is actually signing. You wonder why another student is using an electronic device to speak. Think this can’t happen in your class? According to the U.S. Census, one out of every five Americans has a disability. And some disabilities, such as autism, dyslexia and arthritis, are considered “invisible” disabilities. This means you have a high probability that one of your students will have a disability. As an astronomy instructor, you have the opportunity to reach a wide variety of learners by using creative teaching strategies. I will share some suggestions on how to make astronomy and your part of the universe more accessible for everyone. 116.02 Discovering Astronomy Through Poetry John C. Mannone1 1Barnard Astronomical Society. 2:18 PM - 2:30 PM Gloucester The literature is replete with astronomical references. And much of that literature is poetry. Using this fact, not only can the teacher infuse a new appreciation of astronomy, but also, the student has the opportunity to rediscover history through astronomy. Poetry can be an effective icebreaker in the introduction of new topics in physics and astronomy, as well as a point of conclusion to a lecture. This presentation will give examples of these things from the ancient literature (sacred Hebraic texts), classical literature (Homer’s Iliad and Odyssey), traditional poetry (Longfellow, Tennyson and Poe) and modern literature (Frost, Kooser, and others, including the contemporary work of this author). 116.03 Amazing Space: Explanations, Investigations, & 3D Visualizations Frank Summers1 1STScI. 2:30 PM - 2:42 PM Gloucester The Amazing Space website is STScI's online resource for communicating Hubble discoveries and other astronomical wonders to students and teachers everywhere. Our team has developed a broad suite of materials, readings, activities, and visuals that are not only engaging and exciting, but also standards-based and fully supported so that they can be easily used within state and national curricula. These products include stunning imagery, grade-level readings, trading card games, online interactives, and scientific visualizations. We are currently exploring the potential use of stereo 3D in astronomy education. 116.04 A starry message from the Starry Messenger Michael Francis1 1Stars Science Theater. 2:42 PM - 2:54 PM Gloucester To many the Universe is a closed book of secrets never to be read. Four hundred years ago, an unknown court mathematician in Italy opened that book and laid the foundation for modern science. Galileo Galilei turned his telescope to the heavens to discover mountains and craters on the moon, four moons of Jupiter, and countless stars never before seen. Even more significant was his method of observation and mathematical analysis. He taught future scientists the way to discover the laws of nature. In this session the professor will return to discuss some of his most recent discoveries. Using the gifts of a storyteller and actively involving the audience, Galileo will take his audience through discoveries that changed the very nature of science. First person living history programs have become a staple of informal educational institutions like museums, planetariums and libraries as well as scholastic settings. We will be examining how to use this theatrical technique to educate, entertain and bring Astronomy to life. 116.05 Using Simulations to Visualize Astronomy Concepts Kevin M. Lee1 1Univ. of Nebraska. 2:54 PM - 3:06 PM Gloucester Advances in computer programming environments and the internet have made sophisticated simulations abundant and instantly accessible. This presentation will showcase simulations developed by the University of Nebraska’s Astronomy Education Group that are publicly available on the web at http://astro.unl.edu. These interactive tools can be extremely useful in helping college students visualize challenging topics. Methods for using these tools interactively in the classroom through having a dialog with students, asking them to record predictions, and providing feedback on think-pair-share questions will be discussed. 116.06 The Science in Science Fiction: Using Popular Entertainment as a Gateway Gibor S. Basri1 1UC, Berkeley. 3:06 PM - 3:18 PM Gloucester Science fiction on television and in movies reaches a wide audience of young people. Some of them are avid fans of particular stories, and more are enthralled by some of the special effects and other science fiction themes that have become ever more compelling as media technology improves. It actually doesn't matter whether the physics behind the science fiction is solid, the latest in speculative theory, or absolute nonsense - all provide a backdrop against which to present solid science. I'll talk about the opportunities provided by a few recent series and movies and how they can be woven into discussions of physics, astrophysics, or how science really works. 116.07 Entertainment with Learning Value in Astronomy Classes Alan P. Marscher1 1Boston Univ.. 3:18 PM - 3:30 PM Gloucester As all teachers know, learning requires the attention of the students, which tends to wane as time goes on during a class. Entertainment is a means of restoring that attention. It is even more effective at reaching the goals of the class if the content of the entertainment reinforces the lesson. The presenter will demonstrate how he does this through songs that he composes and performs at selected times in some of his classes. 117 Remembering John Huchra Special Session Oval Room, Fairmont Copley Plaza Monday, May 23, 2011, 3:40 PM - 4:30 PM 118 Stellar Astrophysics from the Kepler Mission Invited Session America Ballroom 118.01 Stellar Astrophysics from the Kepler Mission Ronald L. Gilliland1 1STScI. 3:40 PM - 4:30 PM America Ballroom Through a qualitatively unique combination of both highly precise and nearly continuous multi-year, time-series photometry on 150,000 stars, Kepler is providing fundamentally new stellar astrophysics insights. In this talk I will introduce the characteristics of Kepler observations and results relevant to these studies. Some examples: (1) Stars like the Sun show low-amplitude acoustic oscillations. Kepler has provided better asteroseismic results for hundreds of solar-like stars than existed previously for only about 25 cases. (2) The recent detection of gravity mode oscillations excited in the deep interior of red giants, coupled with study of acoustic modes on the same stars is providing the meaningful constraints on stellar evolution theory long promised by asteroseismology. (3) On the timescale of several hours most relevant to the Kepler planet search program, we know from SOHO observations that the Sun varies by about 10 parts per million. Kepler is now providing measurements of this variability, with results averaging somewhat more than the Sun for thousands of stars. The era of ensemble studies of statistically robust samples of stars for asteroseismology and low-level variability possible previously only for the Sun has now begun. Monday, May 23, 2011, 4:30 PM - 6:00 PM 119 Evolution of Galaxies I Oral Session America North 119.01 Galaxy Formation On A Moving Mesh: Technique And Global Baryonic Properties Mark Vogelsberger1 1Harvard/CfA. 4:30 PM - 4:40 PM America North We present cosmological hydrodynamics simulations to study galaxy formation using the moving mesh code AREPO. We introduce the simulations, numerical techniques and discuss results of the global baryon statistics. Our simulations include primordial cooling taking into account photo-ionization due to a spatially uniform UV background, a two-phase model to describe gas of the interstellar medium, and a star formation method. To contrast our results to previous calculations with a similar physics implementation, we repeat all simulations with the well-tested SPH-code GADGET. Both codes use an identical gravity solver and include the same sub-resolution physics, but use a completely different method to solve the inviscid Euler equations. This allows us to estimate the impact of hydro solver uncertainties on the results of cosmological hydrodynamics calculations. The global baryon statistics differ between the two simulation methods significantly. AREPO shows systematically higher star formation rates, lower mean temperatures over the simulation volume and different mass fractions in gas phases. Although both codes use the same cooling implementation, the cooling rates in AREPO are larger than those in GADGET. These systematic differences demonstrate that inaccuracies in hydro solvers can lead to comparatively large uncertainties in the baryon characteristics. 119.02 Galaxy Formation on a Moving Mesh: Baryonic Properties of Galaxies and Halos Dusan Keres1, M. Vogelsberger2, V. Springel3, L. Hernquist4 1Theoretical Astrophysics Center, UC Berkeley, 2ITC, Harvard, 3Heidelberg Institute for Theoretical Studies, Germany, 4Harvard University. 4:40 PM - 4:50 PM America North We present new type of cosmological hydrodynamic simulations to study formation of galaxies. Simulations were performed using newly developed moving mesh code AREPO in a cosmological box evolved to z=0. We compare the results from this new technique to the results from well-tested SPH code GADGET-3 which uses identical gravity solver, which enables to cleanly test the differences in hydrodynamics. We found several important, systematic differences in properties of galaxies and gaseous components of halos. These include significantly more extended disks and faster cooling of the hot halo gas in massive halos in AREPO. Owing to hierarchical nature of halo and galaxy buildup these differences than propagate to many other properties of simulated halos and galaxies. Given the advantages of hydrodynamic scheme in AREPO in idealized test problems, as well as tests we did in cosmological environment, our new findings are questioning reliability of some the previous results based on SPH technique. 119.03D Probing the Accretion of Gas onto Galaxies: Opportunities and Pitfalls Claude-Andre Faucher-Giguere1 1University of California, Berkeley. 4:50 PM - 5:10 PM America North Galaxies must continuously accrete gas from the intergalactic medium in order to sustain their observed star formation rates. How this accretion proceeds is a fundamental problem in galaxy formation, as it determines how rapidly galaxies can grow as a function of mass and redshift, as well as the efficiency of feedback processes. While theoretical work predicts that galaxies acquire most of their baryons via the "cold mode", observations have so far not found clear traces of the cold streams. I will discuss results from a research program aimed at robustly quantifying the observational signatures of the cold mode, focusing on Ly-alpha emission and absorption and their connection to high-redshift "Ly-alpha blobs" and halo absorbers. In doing so, I will highlight some of the theoretical challenges involved, which can jeopardize this unique opportunity to test a physical prediction of galaxy formation if not addressed properly. 119.04 Ripples in Outer Gas Disks: A Calorimeter of Gravity Sukanya Chakrabarti1 1Florida Atlantic University. 5:10 PM - 5:20 PM America North In recent papers, we have shown that analysis of observed disturbances in extended HI disks can be used to constrain the mass and current location of galactic satellites (Chakrabarti & Blitz 2009; Chakrabarti & Blitz 2011; Chakrabarti, Bigiel, Chang & Blitz 2011). This method, known as Tidal Analysis, was developed to characterize dark matter sub-structure and does not require any knowledge of the optical light from galactic satellites. Here, we explore the role of halo concentration and shape in producing these disturbances. Specifically, we investigate if disturbances in extended HI disks can be used as an observational probe of the concentration of the dark matter halo of the primary galaxy. We also report recent results on the analysis of halo shapes on the production of disturbances in extended HI disks. 119.05 Star Formation Quenching in Hickson Compact Groups: Death by Debris? Michelle E. Cluver1, P. Appleton2, J. Rasmussen3, U. Lisenfeld4, P. Guillard1, P. Ogle1, L. Verdes-Montenegro5, M. Yun6, T. Jarrett7, T. Bitsakis8, C. K. Xu2 1SSC, Caltech, 2NHSC, Caltech, 3Dark Cosmology Centre, Denmark, 4Universidad de Granada, Spain, 5Instituto de Astrofisica de Andalucia, Spain, 6University of Massachusetts, 7IPAC, Caltech, 8University of Crete, Greece. 5:20 PM - 5:30 PM America North Recent studies show that compact groups appear to follow an evolutionary sequence, linked to gas depletion, caused by interactions in the dense environment. In mid-infrared color-color space, galaxies in Hickson Compact Groups (HCGs) show a roughly bimodal separation into dusty, star forming and dust-free, evolved systems. This appears to correlate with HI-depletion, but not the presence of hot X-ray gas. We present results from our Spitzer spectroscopy study of a sample of 23 HCGs, where we find that galaxies with intermediate mid-infrared colors preferentially show enhanced warm H2 emission (i.e. not associated with star formation). We propose a hypothesis where group galaxies collide with previously stripped tidal material, thus producing shock-heated H2 emission. The evolution from gas-rich to gas-poor is accelerated due to galaxies experiencing stochastic heating and/or viscous stripping, which effectively shuts down star formation, causing them to move rapidly from actively star forming to passively evolving systems (i.e. dominated by an old stellar population). 119.06 A Multiwavelength Study of an Assembling Galaxy Cluster : AGN and Starburst Outflows Emily E. Freeland1 1Texas A&M University. 5:30 PM - 5:40 PM America North Galaxy groups are increasingly recognized as a key environment for transforming galaxy morphologies and star formation rates. Current research is focused on illuminating specific physical processes responsible for galaxy evolution in these systems. Super-Group 1120-12 consists of four virialized groups at z~0.36 that will merge and form a cluster comparable in mass to Coma by the current epoch. Using multiwavelength (X-ray, UV, Optical, 24 micron, Radio) imaging and spectroscopic data we identify numerous AGN, starburst, and star-forming galaxies and characterize their associated outflows and physical properties in the context of the group environment. 120 Dark Matter & Dark Energy/Large Scale Structures, Cosmic Distance Scale Oral Session America Central 120.01D Understanding Dark Matter Halos with Tidal Caustics Robyn E. Sanderson1 1Kapteyn Institute, Netherlands. 4:30 PM - 4:50 PM America Central Recently, large-scale sky surveys and deep follow-up images have discovered a wealth of tidal debris around our Galaxy and others nearby. This debris can give clues to the shapes and masses of the dark matter haloes surrounding these galaxies, as well as those of the dwarf galaxies that were tidally disrupted to form the debris. The class of tidal features known variously as ``shells'' or ``umbrellas" comprises debris that has arisen from minor (high-mass-ratio) mergers with low orbital angular momentum; the nearly radial orbits of the debris give rise to a unique shape and a universal radial density profile. The profile takes this form because the dynamics of the debris can be described by a modified version of the mathematical theory of caustics. Based on this universality, I present a new method for constraining multiple parameters of a minor merger in an external galaxy using only the two-dimensional image of the debris. 120.02D Influence of Multiple Deflections on Weak Lensing Measurements of Dark Matter Halo Shapes Paul Howell1 1Boston Univ.. 4:50 PM - 5:10 PM America Central Statistical weak gravitational lensing of background galaxy images by foreground galaxies is now a widely used and powerful tool to probe the distribution of galactic dark matter. However, such analysis often depends on an assumption of a single, weak deflection of the background rays by a foreground lensing object. I will present results that demonstrate the importance of considering multiple deflections when interpreting weak shear results. In particular, I show that multiple deflections can introduce systematic depression of γ+ - the anisotropic shear with respect to the major axis of the lens, and a corresponding amplification of γ-. Such systematics can lead to reduced estimates of the degree of flattening of galaxy dark matter halos, or even the conclusion that dark matter halos are anti-aligned with the light. I create two complimentary simulation spaces to explore these effects. One is a simple system consisting of a single lens whose dark matter halo shape and orientation are known. The subject lens is then embedded in an environment of masses distributed in redshift space. Apparent shear of background sources is found in the usual way and results are tabulated both using apparent lens shape and PA (as an observer would) and using actual shape and PA. A second simulation space replicates as nearly as possible a real observational dataset. I use this simulation to help overcome the systematic effects introduced by multiple deflections to infer actual halo shapes. From this result, I make a modest (95%) detection of flattened dark matter halos aligned with the light and that an NFW type density profile is preferred (95%) over an isothermal density profile. Detection of an isotropic lensing signal as demanded by MOND is similarly excluded. Support from the National Science Foundation under contract AST-0708468 is gratefully acknowledged. 120.03 Structure Formation Can Hint on the Quantum-mixed Nature of Dark Matter Mikhail Medvedev1 1University of Kansas. 5:10 PM - 5:20 PM America Central What happens to a dark matter particle trapped in a static gravitational potential of a halo? The obvious answer that it will remain gravitationally bound forever appears to be not quite true for a quantum-mixed particle, like a neutralino, for example. We will show that the particle can gradually and irreversibly escape, or ``evaporate'', from the gravitational well --- the effect that has no counterpart in classical physics. This new effect is not related to the well-known processes such as flavor oscillations, particle decay, quantum tunneling, etc. Further, we investigated how quantum evaporation would affect the structure formation. It was found that the flavor-mixed dark matter model can simultaneously explain two outstanding problems of cosmology, namely the dark halo cusp problem and the sub-structure (the "missing satellites") problem. [This work is supported by DE-FG02-07ER54940, AST-0708213, NNX-08AL39G.] 120.04 Measuring the 3D Clustering of Undetected Galaxies Through Cross Correlation of their Cumulative Flux Fluctuations from Multiple Spectral Lines Eli Visbal1, A. Loeb1 1Harvard University. 5:20 PM - 5:30 PM America Central We discuss a method for detecting the emission from high redshift galaxies by cross correlating flux fluctuations from multiple spectral lines. If one can fit and subtract away the continuum emission with a smooth function of frequency, the remaining signal contains fluctuations of flux with frequency and angle from line emitting galaxies. Over a particular small range of observed frequencies, these fluctuations will originate from sources corresponding to a series of different redshifts, one for each emission line. It is possible to statistically isolate the fluctuations at a particular redshift by cross correlating emission originating from the same redshift, but in different emission lines. This technique will allow detection of clustering fluctuations from the faintest galaxies which individually cannot be detected, but which contribute substantially to the total signal due to their large numbers. We describe these fluctuations quantitatively through the line cross power spectrum. As an example of a particular application of this technique, we calculate the signal-to-noise ratio for a measurement of the cross power spectrum of the OI(63 micron) and OIII(52 micron) fine structure lines with the proposed Space Infrared Telescope for Cosmology and Astrophysics. We find that the cross power spectrum can be measured beyond a redshift of z=8. Such observations could constrain the evolution of the metallicity, bias, and duty cycle of faint galaxies at high redshifts and may also be sensitive to the reionization history through its effect on the minimum mass of galaxies. As another example, we consider the cross power spectrum of CO line emission measured with a large ground based telescope like CCAT and 21-cm radiation originating from hydrogen in galaxies after reionization with an interferometer similar in scale to MWA, but optimized for post-reionization redshifts. 120.05 The Halo Occupation Distribution of Active Galactic Nuclei Suchetana Chatterjee1, D. Nagai1, J. Richardson1, Z. Zheng1, C. Degraf2, T. DiMatteo2 1Yale University, 2Carnegie Mellon University. 5:30 PM - 5:40 PM America Central We investigate the halo occupation distribution of active galactic nuclei (AGN) using a state-of-the-art cosmological hydrodynamic simulation that self-consistently incorporates the growth and feedback of supermassive black holes and the physics of galaxy formation (DiMatteo et al.\ 2008). We show that the mean occupation function can be modeled as a softened step function for central AGN and a power law for the satellite population. The satellite occupation is consistent with weak redshift evolution and a power law index of unity. The number of satellite black holes at a given halo mass follows a Poisson distribution. We show that at low redshifts (z=1.0) feedback from AGN is responsible for higher suppression of black hole growth in higher mass halos. This effect introduces a bias in the correlation between instantaneous AGN luminosity and the host halo mass, making AGN clustering depend weakly on luminosity at low redshifts. We show that the radial distribution of AGN follows a power law which is fundamentally different from those of galaxies and dark matter. The best-fit power law index is -2.26 ± 0.23. The power law exponent do not show any evolution with redshift, host halo mass and AGN luminosity within statistical limits. Incorporating the environmental dependence of supermassive black hole accretion and feedback, our formalism provides the most complete theoretical tool for interpreting current and future measurements of AGN clustering. 121 Stars, Dwarfs, Stellar, Circumstellar Disks Oral Session America South 121.01 Large Ampltiude, Quasi-Periodic Variability of a Cool Brown Dwarf Jacqueline Radigan1, R. Jayawardhana1, D. Lafreniere2, E. Artigau2 1University of Toronto, Canada, 2Universite de Montreal, Canada. 4:30 PM - 4:40 PM America South We present continuous photometric monitoring of an early T-type brown dwarf in the near-infrared. Observations over 7 nights indicate that the target is variable with a period of ~7.7 hours and peak-to-peak amplitudes of up to 30% in the J band, the largest ever reported for a field brown dwarf. The evolving nature of the light curve, which displays phase changes in multi-epoch observations over months, suggests that atmospheric surface features --most likely heterogeneous clouds---are responsible. We also discuss our attempts to use combinations of current 1D 'cloudy' and 'clear' model atmospheres to reproduce simultaneously both the J, H, Ks light curve amplitudes as well as the target's observed spectral energy distribution. This object joins the T2.5 dwarf SIMP0136 discovered by Artigau and coworkers as the second L/T transition brown dwarf to display large-amplitude variability on rotational timescales, suggesting that the fragmentation of dust clouds at the L/T transition may contribute to the abrupt decline in condensate opacity and J-band brightening observed to occur over this regime. Furthermore, the presence of discrete, long-lived cloud features on these objects offers the potential to map evolving weather patterns, and hence extend studies of atmospheric circulation beyond our solar system, to a substellar mass regime never before probed. 121.02 Substellar Objects in Nearby Young Clusters (SONYC): Latest Results Ray Jayawardhana1, K. Muzic1, A. Scholz2, V. Geers3, M. Tamura4 1University of Toronto, Canada, 2Dublin Institute for Advanced Studies, Ireland, 3ETH, Switzerland, 4National Astronomical Observatory of Japan, Japan. 4:40 PM - 4:50 PM America South The origins and characteristics of the lowest mass free-floating objects constitute a major question in the study of star and planet formation. Our on-going SONYC (Substellar Objects in Nearby Young Clusters) survey uses extremely deep wide-field optical and near-infrared imaging, with follow-up spectroscopy on 8m-class telescopes, in combination with Spitzer photometry to explore substellar objects with masses down to a few times that of Jupiter. Here we present our latest findings for three nearby star-forming regions (NGC 1333, rho Oph and Cha I), describe the lowest mass objects we have found so far, and discuss the minimum mass limit for star formation. 121.03 DASCH Photometry Of KU Cygni: An 8-yr Dimming Around 1900 Sumin Tang1, J. Grindlay1, E. Los1, M. Servillat1 1Harvard-Smithsonian Center for Astrophysics. 4:50 PM - 5:00 PM America South KU Cygni is an Algol-type eclipsing binary consisted of a F-type main sequence star (gainer) with a large accretion disk, and a K5III red giant (donor). Here we present the discovery of an 8-yr dimming begining in 1895 found from its 100 yr DASCH light curve. It showed a 0.7 mag slow dimming from 1895 to 1903, and then quickly brightened back to normal state in 1903. After 1903, KU Cygni was stable within 0.2 mag in non-eclipsing phases when our data are available (i.e. 1909-1952 and 1962-1990). The dimming event is probably caused by increases in dust extinction surrounding the gainer, and the quick brightening could be due to the evaporation of dust transported inwards through the disk surrounding the gainer. The dust excess during the dimming event might arise from clumps of dusty gas ejected from the red giant donor. 121.04 Resolving The CO Snow Line In The Disk Around HD 163296 Chunhua Qi1, P. D'Alessio2, K. I. Öberg1, D. J. Wilner1, A. M. Hughes1, S. A. Andrews1, S. Ayala2 1Harvard Smithsonian, CfA, 2Universidad Nacional Autonóma de México, Mexico. 5:00 PM - 5:10 PM America South We report Submillimeter Array (SMA) observations of multiple lines of CO (J=2-1, 3-2 and 6-5) and CO isotopologues (13CO J=2-1, C18O J=2-1 and C17O J=3-2) in the disk around the Herbig Ae star HD 163296 at ~ 2 arcsec (250 AU) resolution, and we interpret these data in the framework of a model that constrains the radial and vertical location of the line emission regions. We first develop a set of physically self-consistent accretion disk models with exponentially tapered edges that reproduces the observed spectral energy distribution and spatially resolved millimeter dust continuum emission. We further constrain the vertical structure of the model, taking advantage of the wide range of excitation sampled by the multiple optically thick CO lines, in particular the rarely observed J=6-5 line. The resulting model has a cold midplane populated by large grains with a large scale height. Using this model, we fit for the location of the optically thinner CO isotopologue line emissions and find they are confined between two vertical boundaries: a lower boundary around 19 K (due to CO freeze-out) and an upper boundary where the surface density is around 1021 cm-2 (due to photodissociation). If all CO isotopologues freeze out at 19 K, then we find isotopic ratios of 12C/13C, 16O/18O and 18O/17O consistent with the quiescent interstellar gas-phase values. We discuss the relevance of the CO freeze-out on the determination of the fractional abundances of CO and its isotopologues. 121.05 Resolving the Cepheid Mass Discrepancy with Pulsation-Driven Mass Loss Hilding Neilson1, M. Cantiello1, N. Langer1 1University of Bonn, Germany. 5:10 PM - 5:20 PM America South The Cepheid Mass Discrepancy is the difference between mass predictions using stellar evolution and stellar pulsation calculations. Currently, masses from stellar pulsation are typically 10-20% smaller than those from evolution models. This problem is a challenge for the understanding of stellar evolution and pulsation. One potential solution is enhanced mass loss during the Cepheid stage of evolution. We use state-of-the-art stellar evolution models and find that the combination of moderate convective core overshooting and pulsation-driven mass loss resolves the Cepheid Mass Discrepancy. 121.06 Linear Polarization Light Curves of Oblique Magnetic Rotators Richard Ignace1, K. T. Hole1, J. P. Cassinelli2, G. D. Henson1 1East Tennessee State Univ., 2University of Wisconsin. 5:20 PM - 5:30 PM America South The quality and quantity of polarimetric data being collected for stellar sources creates new opportunities for studying stellar properties and evolution, and also leads to new challenges for modeling and interpreting such data. Inspired by fresh prospects for detecting the Hanle effect to study photospheric magnetic fields, we have focused attention on purely geometrical aspects for polarimetric variability in the example of oblique magnetic rotators. In the case of axisymmetric fields, we highlight two key facts: (a) polarimetric lightcurves necessarily exhibit a certain time symmetry with rotation phase, and (b) variations in the polarization position angle can be modeled based on geometrical projection effects, independent of the photospheric magnetic field. These conclusions also have general applicability, such as to Thomson scattering and the transverse Zeeman effect. The authors gratefully acknowledge that funding for this work was provided by the National Science Foundation, grant AST-0807664. 122 Binary Stellar Systems, X-ray Binaries Oral Session St. George CD 122.01 Using Black Hole--Pulsar Binaries to Search for a Warped Extra Dimension Michael Kavic1, J. Simonetti2, D. Minic2 1The College of New Jersey, 2Virginia Tech. 4:30 PM - 4:40 PM St. George CD We will discuss the observable effects of enhanced black-hole mass loss in a black hole--neutron star (BH--NS) binary, due to the presence of a warped extra spatial dimension in the braneworld scenario. For some masses and orbital parameters in the expected ranges the binary components would outspiral, the opposite of the behavior due to energy loss from gravitational radiation alone. If the NS is a pulsar, observations of the rate of change of the orbital period with a precision obtained for the Binary Pulsar B1913+16 could easily detect the effect of mass loss. Observations of a BH--pulsar system could set considerably better limits on these braneworld models than could be determined by torsion-balance gravity experiments in the foreseeable future. 122.02 Chandra Watches Over A Decade Of Variability In M31 Globular Clusters Robin Barnard1, Z. Li1, M. Garcia1, S. Murray2 1Harvard-Smithsonian Center for Astrophysics, 2Johns Hopkins University. 4:40 PM - 4:50 PM St. George CD The central region of M31 has been monitored with Chandra > 120 times over the last ~11 years. In this region we find X-ray sources corresponding to 35 out of ~420 globular clusters; these are highly likely to be X-ray binaries. We have created long-term, calibrated lightcurves for all 35 sources, and will present highlights of our variability survey. We have detected significant variability in all the sources with 0.3-10 keV luminosity > ~2x10E+36 erg/s. Since the emission spectra of background active galaxies often resemble those of X-ray binaries, the long term variability will be a valuable tool for identifying X-ray binaries in the remaining 400 sources in our field. This work is funded by Chandra grant GO9-0100X and HST grant GO-1101. 122.03 The intriguing Case of the New Supergiant Fast X-Ray Transient Class: An Update Pietro Ubertini1, L. Sidoli2, A. Bazzano1, V. Sguera3 1INAF/IASF-Roma, Italy, 2INAF/IASF-Milano, Italy, 3INAF/IASF-Bologna, Italy. 4:50 PM - 5:00 PM St. George CD Supergiant Fast X-ray Transients (SFXTs) are an intriguing subclass of High Mass X-ray Binaries hosting a blue supergiant companion. They display brief outbursts composed by bright flares lasting a few thousands seconds, during which an X-ray luminosity of 1E36-1E37 erg/s is reached. Their extreme X-ray variability, with a dynamic range of 3 to 5 orders of magnitudes from quiescence to the outburst peak, is still a matter of debate: in massive binaries where the compact object should be embedded all the time within the strong wind from the supergiant companion, a transient X-ray emission is very difficult to explain. The determination of pulse and orbital periodicities are crucial to cast light on the outburst mechanism and on the evolutionary status of these X-ray binaries. The number of SFXTs where X-ray periodicities have been discovered is indeed continuously growing thanks to timing analysis of large datasets, especially from INTEGRAL/IBIS and Swift/BAT. We will review the most recently found periodicities and their important implications for the physical mechanisms proposed to explain the SFXTs outbursts. 122.04 Observing Mass Transfer in a Neglected Interacting Binary Star Phillip A. Reed1 1Kutztown University. 5:00 PM - 5:10 PM St. George CD The eclipsing and interacting binary star R Arae is a very interesting system that has unfortunately been neglected. The few spectroscopic studies of the system report badly blended absorption lines that indicate mass transfer, but until now there has been no orbital period study to conclusively show a real period change resulting from mass transfer. In this study, new data are combined with those found in the available literature and in the database of the American Association of Variable Star Observers to construct the first ephemeris curve for R Ara, which spans more than a century since its discovery in 1894. Average orbital period change and conservative mass transfer rates are presented. 122.05 Magnetospheric Accretion Shocks In The X-ray Spectrum Of The Ultra-compact Binary 4u 1626-67 Norbert S. Schulz1, H. L. Marshall1, D. Chakrabarty1 1MIT. 5:10 PM - 5:20 PM St. George CD In 2008 the ultra-compact binary pulsar underwent another episode of torque reversal since the one in the early 1990s. We observed the X-ray source one year after the event with the HETG spectrometer onboard Chandra. While the light curve before torque reversal is featureless, it now shows enhanced flaring similar to observations before the first reversal episode. The X-ray continuum is fit by the same spectral model as before, but exhibits significantly larger blackbody temperatures and smaller emission radii. The spectrum for the first time shows a narrow Fe K fluorescence line. We show while a photo-ionized plasma cannot fit the Ne and O Doppler line emissions, a collisionally ionized plasma provides a better description of the data. We propose, that the nature of the Doppler line pairs can then be described as magnetospheric accretion shocks and shoked matter moving towards the magnetospheric poles. 122.06 Distribution And Nature Of The Accretion-powered Binaries In The Galactic Center Region From The Chandra BLS Jonathan E. Grindlay1, J. Hong1, M. Servillat1, P. Zhao1, B. Allen1, M. van den Berg2 1Harvard-Smithsonian, CfA, 2Utrecht University, Netherlands. 5:20 PM - 5:30 PM St. George CD We have completed the analysis of the Chandra Bulge Latitude Survey (BLS), a close-tiled mosaic of 36 ACIS-I fields obtained with Chandra in cycles 7 - 9 and covering (l, b) ~ +/-0.3, +/-1.4deg. With 15ksec exposures per field, some 2500 sources are detected, with luminosities Lx(0.3-8keV) >~10^32 erg/s. This survey maps the latitude distribution of the galactic center region (GCR) sources for comparison with the longitude distribution of the Wang et al (2002) survey. The BLS extends below the plane to (just) include the "Limiting Window" field (b = -1.3deg, the closest low extinction window to SgrA* with Av ~4) we originally observed in a 100ksec pointing and which was recently observed in a much deeper pointing by Revnivtsev et al to study the Galactic Ridge. From our optical (VRI; CTIO-4m/Mosaic) and nIR (JHK; CTIO-4m/ISPI) images, we identify foreground sources and constrain the Bulge sources to not be wind-fed high mass systems. By selecting on sources detected in the Hard (>2keV) but not in the Soft (<2keV) bands, we can reject foreground sources and measure the latitude and projected radial distributions of the hard sources in the GCR that are likely dominated by accreting white dwarfs (CVs) but also include quiescent low mass X-ray binaries (qLMXBs). And from comparison with the Wang survey, the combined radial distribution of Lx ~10^32-33 erg/s hard sources in the GCR, which are dominated by accreting compact objects in binaries, is derived for comparison with models of the Bulge and its formation history. 122.07 An Experimental Approach to Population Synthesis of Hot Subdwarf Stars in Binaries Drew R. Clausen1, R. A. Wade1, R. K. Kopparapu1, R. O'Shaughnessy2 1The Pennsylvania State University, 2University of Wisconsin Milwaukee. 5:30 PM - 5:40 PM St. George CD We use the BSE code (Binary Stellar Evolution) of Hurley et al. (2002) to explore the binary formation channels of subdwarf B (sdB) stars, varying parameters that control mass and angular momentum loss from the system, whether or not mass transfer is stable, common envelope ejection efficiency, and the helium ignition point. We choose a large number of plausible initial binary masses and orbital periods (M1, M2, P) by Monte Carlo and follow the evolution of each binary to determine whether an sdB is produced. Sampling our database of simulations uniformly in time, we estimate the "present-day" distribution of sdB binaries with non-degenerate companions. We find that the distributions of periods and companion masses are extremely sensitive to changes in these parameters, and that reproducing the results of previous binary population synthesis studies related to hot subdwarfs requires modifying many assumptions hardwired into BSE. Our models suggest that observations of sdB-F dwarf binaries can constrain the critical mass ratio for stable mass transfer from red giants or α_CE. Partial Support for this work was provided by the National Aeronautics and Space Administration through Chandra Award Number TM8-9007X issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics Space Administration under contract NAS8-03060, with additional support from NASA grant NNX09AC83G. 122.08 Status Report on a Search for F stars with Hidden Hot Subdwarf Companions Richard A. Wade1, D. R. Clausen1, M. A. Stark2, C. V. Griffith1 1Penn State Univ., 2Univ. Michigan/Flint. 5:40 PM - 5:50 PM St. George CD Observations to date preferentially find Galactic hot subdwarf (sdB/sdO) stars in binaries when the subdwarfs are paired with relatively faint companions (G/K/M dwarfs, white dwarfs). This selection bias may distort our perspective of the evolutionary channels that form hot subdwarfs in the galactic disk. A predicted and possibly more numerous population of binaries features a lower-mass, lower-luminosity, longer-lived hot subdwarf hiding in the glare from its brighter companion: the subdwarf + A/early F binaries. Such systems may arise when mass transfer is initiated in the Hertzsprung gap. A survey is underway at Penn State to identify hot subdwarfs paired with early F stars, determine their properties, and establish their space density. The project makes use of ground and space archival data to identify these systems (from their UV excesses) and new spectroscopic observations to refine the sample and determine their orbital periods and other properties. Successful characterization of this group of close binaries should help to challenge, calibrate, or refine models of binary star evolution that are used in population synthesis studies. The motivation, methodology, and status of this search for hidden hot subdwarfs will be presented. This study makes use of NASA archival data from 2MASS and GALEX. Support from NASA grant NNX09AC83G and NSF grant AST-0908642 is gratefully acknowledged. Observations carried out at KPNO and Hobby-Eberly Telescope. 123 Quasars, AGN, Starbursts, and SEDs Oral Session Staffordshire 123.01 Orientation Effects in the Spectral Energy Distributions of High-z 3CRR Sources Including New Far-IR Herschel Data. Joanna Kuraszkiewicz1, B. Wilkes1, P. Barthel2, M. Haas3, S. Willner1, C. Leipski4, M. Ashby1, G. Fazio1 1Harvard-Smithsonian, CfA, 2Kapteyn Institute, Netherlands, 3Astronomisches Institut, Ruhr-University, Germany, 4MPIA, Germany. 4:30 PM - 4:40 PM Staffordshire A critical problem in understanding AGN and their contribution to the accretion power of the Universe is deducing their intrinsic properties from the observed properties, which are highly orientation/obscuration dependent. One way to select AGN samples that are unbiased by the effects of orientation/obscuration is low-frequency radio emission. Here we study a complete, 178 MHz radio flux-limited, orientation unbiased sample of 3CRR sources with high-redshift (1 < z < 2). At these redshifts the radio luminosities of the 3CRR sources are high ensuring that all sources in the sample are AGN. The sample includes 20 quasars and 18 radio galaxies, thought to be AGN viewed edge-on according to unification models. The estimate of orientation is provided by the radio core dominance. We have begun studies of the Chandra X-ray and Spitzer IR properties and their dependence on orientation. Here we extend these studies by compiling full (radio-to-X-ray) spectral energy distributions (SEDs)complementing the Chandra and Spitzer data with existing data from the literature and astronomical databases. Until recently one crucial gap remained in our multi-wavelength SED coverage: the far-infrared, which is emitted by dust and is key to measuring star formation in our sources. ESA's newly operating `cornerstone' mission, Herschel, is the first observatory to cover the 60-670um (observed frame) range. We show for the first time the full SEDs of the high-z 3CRR sources including the new, complementary Herschel data. We present preliminary results of our study of the dependence of the SEDs on orientation (the 3CRR sources span a full range of inclination angles) and disentangle orientation effects from other effects (such as e.g. accretion rate). 123.02 Eddington Ratios Of Obscured GOODS AGN at 0.51 and that we are observing them in a slow- or no-growth state. Our bolometric luminosities, based on dust-corrected central point-source SEDs, have a smaller spread than do alternative estimates from corrections to the X-ray luminosity or direct SED integration, suggesting our new method yields a better measure of bolometric luminosity; these values also agree with theoretical models of AGN luminosity based on a unification scenario. 123.03 Building Up the Red-Sequence: The AGN-Starburst Connection Laura Trouille1, C. Tremonti2, R. Hickox3 1Northwestern University CIERA Postdoctoral Fellow, 2University of Wisconsin - Madison, 3Durham, United Kingdom. 4:50 PM - 5:00 PM Staffordshire Post-starburst galaxies, also known as K+A or E+A galaxies because of the characteristic features in their spectra, have recently undergone an abrupt cessation of active star formation (within 20-500 Myr). This exceptional and rare stage in galaxy evolution is thought to occur during the transition from gas-rich, star-forming galaxies into early-types. While it is poorly understood what causes the abrupt end of their star formation, there is strong evidence that galaxy-galaxy tidal interactions or mergers trigger the starburst in many of these galaxies. This same mechanism for triggering intensive star formation may also cause strong fuelling onto a central supermassive black hole. By studying the evolution of the properties of post-starbursts, we obtain insights into the origin of the red-sequence and key properties of the AGN-starburst connection. The use of post-starbursts as probes is only now feasible with the advent of large optical spectroscopic surveys. Here we compare results from the ~3000 SDSS DR7 post-starbursts at z~0.1 (for which ~60 have associated archival Chandra data) and the ~200 post-starbursts from the DEEP2, zCOSMOS, and OPTX surveys at z~0.9 (accompanied by deep Chandra imaging). A key benefit of studying post-starburst galaxies is that they are natural chronometers; detailed population synthesis modeling provides an estimate of the time since the peak star-formation event. In this study we address the following questions: 1) Does a visual inspection for near-neighbors and tidal disruptions in our low-redshift sample show a trend with post-starburst age? 2) Do post-starbursts move across optical emission-line diagnostic diagrams as they age and what does this tell us about the time-delay between starburst activity and AGN fueling? 3) Are post-starburst X-ray properties (for individually detected sources and on average via X-ray stacking) correlated with time since peak in star formation activity? 123.04 Spectral Energy Distribution of Far infrared Detected Quasars in the Lockman Hole Yu Dai1, J. Huang1, A. Omont2, M. Elvis1, C. Willmer3, E. Hatziminaoglou4, G. Fazio1 1Harvard-Smithsonian Center for Astrophysics, 2Institut d'Astrophysique de Paris, France, 3Steward Observatory, University of Arizona, 4Dept of Astrophysics, Oxford University, United Kingdom. 5:00 PM - 5:10 PM Staffordshire The far-infrared (FIR) behavior of quasars is important in disentangling the Starburst (SB) and Active Galactic Nucleus (AGN) contributions to the source. Therefore, we constructed a 24 micron selected Type I quasar sample to study their FIR properties. All of the sources were spectroscopically identified from either the Hectospec on MMT or the Sloan Digital Sky Survey (SDSS). Of the total 432 sources, 37 were detected in the HERMES survey. We compared their SEDs to existing quasar templates, and found that these FIR bright quasars differ only by an additional dust component. Further studies on the origin of the FIR emission reveal the interweaving roles SB and AGN play in powering the dust emission, depending on the dust temperature, luminosities, and the shapes of individual SEDs. The dust temperature has a wide range from 21K to 164K with a median of ~50K, indicating more than one heating mechanism. We argue that the FIR emission and the quasar activities are either serendipitous occurrences or the FIR emission happened in a very short time scale. 123.05 The Quasar SED Mixing Diagram Heng Hao1, M. Elvis2, F. Civano2 1Harvard Univ., 2SAO. 5:10 PM - 5:20 PM Staffordshire We present a useful new diagram for characterizing the quasar-host-reddening mixture for AGN SEDs. This "mixing diagram" is based on a detailed study of 413 X-ray selected Type 1 AGN SEDs from the XMM-COSMOS Survey (Elvis, Hao, et al., 2011). The mixing diagram plots the near-IR (1-3micron) spectral slope against the optical (0.3-1micron) slope to form a generalized 'color-color' diagram. A pure AGN continuum (Elvis et al., 1994, E94) and pure host galaxies are located at clear and distinct positions on the mixing diagram. The lines joining them indicate the fraction of host contribution to each AGN. The reddening vector is almost perpendicular to these mixing lines, and so is easily measured independently. The mixing diagram shows that ~90% of the AGNs lie on mixing curves between the mean E94 AGN SED and a host galaxy, with only modest reddening [E(B-V)=0.1-0.2] (Hao et al., 2011a). Lower luminosity and lower Eddington ratio AGNs have a larger host galaxy fraction, as expected. Optically selected samples (SDSS) have smaller host galaxy fractions. There is some intrinsic scatter around the E94 mean SED. A substantial minority, 10%, of the XMM-COSMOS AGNs are inconsistent with any AGN+host+reddening mix. These AGNs have weak or non-existent near-IR bumps, suggesting a lack of the hot dust characteristic of AGNs (Hao et al., 2010). A similar fraction of these "hot dust poor" (HDP) quasars are found in the Elvis et al. 1994 (BQS) and Richards et al. 2006 (SDSS) samples (Hao et al., 2011b). The fraction of "hot dust poor" AGNs grows to ~20% at z>2 (Hao et al. 2010). The proposed 'cosmic cycle' of SMBH and galaxy co-evolution (e.g. Hopkins et al., 2006) can be shown as tracks on the mixing diagram. The mixing diagram definition could also be expanded to other wavelengths. 123.06 Observed Quasar Structure Rudolph E. Schild1 1Harvard-Smithsonian, CfA. 5:20 PM - 5:30 PM Staffordshire With the introduction of microlensing (nano-lensing) and reverberation analysis, understanding of the luminous structure surrounding quasars has gone from theoretical speculation to an observer's sport. Micro-lensing with day timescale has demonstrated that quasars have structure on scales of 1 R_G which we attribute to the inner edge of the accretion disc, at central distance 70 R_G in lo-hard state (radio loud) Q0957 quasar, indicated by reverberation. Reverberation of the dominant optical continuum has been detected in all 55 hi-soft quasars with brightness data, originating in the dusty torus observed in UV-optical and IR reverberation. Microlensing simulation compared to brightness monitoring shows that 2/3 of the UV-optical continuum originates in the outer torus. The observed color effects observed in the microlensing support the existence of inner and outer luminous structure. 123.07 Lamost Quasar Survey Xuebing Wu1, LAMOST Extragalactic Survey (LEGAS) Team 1Peking University, China. 5:30 PM - 5:40 PM Staffordshire We will introduce the main objectives of the future Chinese LAMOST spectroscopic quasar survey, aiming at discovering 0.4 million new quasars in the next 5 years. This will hopefully provide the largest quasar sample for the further studies of AGNs. The data from the existing and future X-ray surveys will be very helpful in the quasar candidate selection and the constructions of sub-samples of X-ray selected or obscured quasars. We will also describe our improved quasar selection criteria based on the UKIDSS near-IR and SDSS optical colors, and their advantages in recovering the missing quasars in the `redshift desert'. In addition, some recent discoveries of new quasars by the LAMOST commissioning observations will be presented. Tuesday Tuesday, May 24, 2011, 8:00 AM - 7:00 PM 224 The Sun and The Solar System Poster Session Essex Ballroom 224.01 Secular Constraints on the Dynamical History of the Solar System Rebekah Ilene Dawson1, R. Murray-Clay1 1Harvard-Smithsonian Center for Astrophysics. 8:00 AM - 7:00 PM Essex Ballroom Tens of thousands of small bodies comprise the Kuiper Belt, the remnant planetesimals beyond Neptune. Their orbits are thought to have been sculpted during a period of upheaval in the early Solar System, when the giant planets underwent scattering and/or migration. Therefore they are a rich collection of artifacts for Solar System archaeology. In the “classical” region from 40-50 AU, a population of “hot” objects with inclinations up to 30° overlies a flat “cold” population, with distinct physical properties (i.e. size, color, binary fraction); a third population is in orbital resonance with Neptune. Migration of Neptune, the standard explanation for capturing objects into resonance, preserves cold objects formed in situ but does not produce a hot population. Alternatively, Neptune may have undergone a period of high eccentricity during which it scattered hot objects from the inner disk into the classical region, but this scenario does not produce or preserve a cold population. To investigate which histories produce both hot and cold objects, we fully explore the parameter space of Neptune's initial semi-major axis (a) and eccentricity (e) as well as migration, eccentricity damping, and precession timescales. We determine which dynamical processes affect the orbital evolution of Kuiper Belt Objects (KBOs) and model them analytically. We find that to produce an eccentricity distribution of KBOs consistent with major qualitative observed features, Neptune must be scattered to one of two particular regions of parameter space, both located within e > 0.15 and 25 < a < 29 AU, and then migrate to its current location at 30 AU. Its eccentricity must either damp on a timescale < 0.3 Myr or precess* on a timescale < 0.5 Myr. Thus scattering and migration both play roles in the dynamical history of the Solar System. Funded by the NSF GRFP. * Batygin 2011 (in prep) 224.02 Physical Characterization Of 2002 Ve68, A Quasi-moon Of Venus. Tzitlaly Barajas1, M. D. Hicks2, D. Mayes2, H. Rhoades2, J. Somers3, K. Garcia1, J. Foster1, T. Truong1 1California State University Los Angeles, 2Jet Propulsion Laboratory, 3Moorpark College. 8:00 AM - 7:00 PM Essex Ballroom The Near-Earth Object (NEO) 2002 VE68 was discovered by the LONEOS Survey on November 11, 2002 (MPEC 2002-V52). With a semi-major axis of 0.723 AU, 2002 VE68 is in a 1:1 mean motion resonance with Venus and can be considered a quasi-satellite of the planet. Orbital integrations by Mikkola et al. (2004) suggest that 2002 VE68 was likely an NEO injected into its current orbit by a close Earth encounter approximately 7000 years ago and will remain a Venusian quasi-satellite for another 500 years. This object has been designated a Potentially Hazardous Asteroid by the Minor Planet Center. We took advantage of the object's 2010 apparition to collect rotationally resolved Bessel BVRI photometry over the course of three nights (November 10/12/13 2010) using the JPL Table Mountain 0.6-m telescope near Wrightwood, California. The object's mean colors (B-R=1.106+/-0.019 mag; V-R=0.419+/-0.021 mag; R-I=0.348+/-0.014 mag) are most compatible with an X-type spectral classification (Bus Taxonomy). A slight reflectance dip at 0.55 micron is consistent with the deep 0.50 micron feature observed in the spectrum of the E-type asteroid 2867 Steins (Weissman et al. 2008). The spectral resolution that our BVRI photometry affords is often insufficient to resolve the E-M-P sub-classes within the X-spectral complex (Tholen Taxonomy; Zelner et al. 1985). After converting the photometry from magnitude to flux units, we found a best-fit synodic period P_syn = 13.50+/-0.01 hr. Our photometry yields an absolute magnitude H_v=20.59+/-0.02 mag, implying an effective diameter D~200m (rho=0.25). The lightcurve amplitude of 2002 VE68 (~0.9 mag) suggests that it may be a contact binary. 224.03 Rotationally Resolved Photometry of the V-type Near-Earth Asteroid 4055 Magellan (1985 DO2) Karen Garcia1, T. Truong1, M. D. Hicks2, T. Barajas1, J. Foster1 1California State University Los Angeles, 2Jet Propulsion Laboratory. 8:00 AM - 7:00 PM Essex Ballroom The Near-Earth Asteroid (NEA) 4055 Magellan was discovered by Glo Helin at Palomar Mountain (IAUC 4638) and was one of the first known minor planets with surface reflectance properties comparable to that of 4 Vesta (Tholen, 1988). Broad-band photometry and near-IR spectroscopy revealed strong 0.9 and 1.9 micron proxene bands, suggesting a compositional similarity of 4055 Magellan with that of 4 Vesta and the basaltic achondrite meteorites (Cruikshank et al. 1991). In anticipation of the Dawn mission to 4 Vesta we obtained 5 partial nights, 2010 August 9/10/12/13/14, of Bessel R photometry of 4055 Magellan at the Jet Propulsion Laboratory Table Mountain 0.6-m telescope (TMO). We measured a synodic period of 7.488+/-0.001 hr, similar to the 7.475+-0.001 hr period obtained by Pravec et al. (http://www.asu.cas.cz/~ppravec/newres.txt). Our object exhibited a large lightcurve amplitude (delta_M~0.8 mag) implying a highly elongated shape. We used our TMO photometry and the absolute magnitude as tabulated by the Minor Planet Center to construct a rudimentary solar phase curve. We derived a phase parameter g=0.30, similar to the phase behavior as measured by Pravec and colleagues (http://www.asu.cas.cz/~ppravec/neo.html). Our high g implies a shallow solar phase slope, consistent with the object's high albeldo (rho=0.31) obtained from thermal measurements (Delbo et al. 2003). The photometric properties of the V-type 4055 Magellan , such as shallow phase slope and high albedo, are consistent with 4 Vesta, giving us confidence in using NEA vestoids as photometric analogs for 4 Vesta. 224.04 Searching For Hazardous Asteroids Brian Elwood1, A. W. Puckett2, K. Coble1, S. Cortes3 1Chicago State University, 2University of Alaska at Anchorage, 3University of Arizona. 8:00 AM - 7:00 PM Essex Ballroom We are searching for asteroids that are possible threats to our planet using astronomical images. The images were taken with the WIYN 0.9-meter telescope at the Kitt Peak National Observatory outside Tucson, Arizona. A variety of measurements of a selected asteroid’s orbit is collected and added to an astrometry file. This increases the accuracy percentage of predicting the asteroid’s position in the future. The types of software used in this research are Astrometrica, Image J, Find_Orb, and Guide. Astrometrica is an interactive software tool for astrometric data reduction of CCD images. Image J is used to measure the positions of celestial objects. The Find_Orb software is used to generate orbits for the asteroid and the Guide software displays the multiple orbits generated from Find_Orb. This work was supported in part by funding from the IL Space Grant Consortium. 224.05 Additional Los Alamos RAGE Hydrocode Simulations of Effective Mitigation of Porous PHO Objects Robert Weaver1, C. Plesko1, W. Dearholt1 1LANL. 8:00 AM - 7:00 PM Essex Ballroom In this presentation we show new RAGE hydrocode simulations of the effective disruption and mitigation of Earth bound asteroids and other Potentially Hazardous Objects (PHOs) by a strong explosion. This is just one possible method of impact-hazard mitigation. We present RAGE hydrocode models of the shock-generated disruption of PHOs by surface/subsurface nuclear bursts using scenario-specific models from realistic RADAR shape models. The RAGE code has been extensively verified and validated (V&V) We will show 2D models for the disruption by a large energy source at various depths-of-burial on such PHO models (~100 kton - 10 Mton), specifically for the shape of the asteroid 25143 Itokawa. We study the effects of non-uniform composition (rubble pile), porosity, effective source energy, and the optimal depth of burial from the surface explosion to the central explosion. The results of our actual hydrocode modeling shows that the resultant asteroid fragments are given sufficient velocity to escape gravitational recombination and results in effective mitigation of the hazard for ~300 m size objects. 224.06 The Monitoring of Transient Lunar Phenomena Jarrel Doorn1, M. Eaton1, G. Ahrendts1, T. Barker1 1Wheaton College. 8:00 AM - 7:00 PM Essex Ballroom Transient Lunar Phenomena (TLP’s) are described as short-lived changes in the brightness of areas on the face of the Moon. TLP activity has a higher number of reports, though unsubstantiated, in specific areas of the Moon such as the Aristarchus plateau. Our current research includes the division of lunar images taken through multiple filters using a Santa-Barbara Instrument Group (SBIG) ST8-E CCD camera mounted on a 0.45m Centurion telescope. We are also taking spectra of regions such as Aristarchus and the crater Ina, which shows evidence of recent activity (Schultz, P., Staid, M., Pieters, C. Nature, Volume 444, Issue 7116, pp. 184-186, 2006) using an SBIG DSS-7 spectrometer mounted on a 0.30m Schmidt-Cassegrain optical tube assembly on a Software Bisque Paramount drive system. Future research will include infrared imaging of the lunar surface. We are grateful for the support provided by the NASA Rhode Island Space Grant Consortium and the National Geographic Society. 224.07 Formation of Satellites Around Migrating Ice Giant Planets Christopher R. Fuse1, M. Neville1 1Rollins College. 8:00 AM - 7:00 PM Essex Ballroom We have begun a program of assessing outer Solar system formation theories. In that endeavor, we have investigated the formation scenarios of Thommes ejection (Thommes et al. 2001) and the Nice Model (Tsiganis et al. 2006). Our results indicate that Thommes ejection is able to reproduce the satellite systems of Saturn in ~88% of simulations, while the regular moons of Jupiter are formed in ~50% of the simulations. Given the known resonances exerted by the giant planets and the evidence that the outer planets likely experienced significant re-configuration, it is necessary to evaluate the possibility of satellite formation during planetary migration. Thommes ejection theory, where Uranus and Neptune form near Jupiter and are perturbed into their current locations, has been successfully and extensively tested. As both Uranus and Neptune possess a system of moons, an in-depth analysis of the survivability of forming moons around an ejected proto-planet is needed to further assess the validity of the Thommes model. Using an N-body planetary code, we simulated the ejection of proto-planets by Jupiter. Satellite formation was also simulated during the planetary migration. We find that the proto-Uranus and Neptune bodies are able to retain their systems of moons during migration and during a set of control simulations. The systems of moons around either proto-planet do not resemble the current satellites. The findings of these simulations will be discussed. Additional simulations, investigating the viability of the Nice Model will be the focus of future work. 224.08 Investigations on Gas Giant Moon Formation During Thommes Ejection Mary H. Neville1, C. Fuse1 1Rollins College. 8:00 AM - 7:00 PM Essex Ballroom The unique orbital configurations and mass distributions observed in the satellite systems of Jupiter and Saturn provide a means to assess outer Solar system evolution theories. Thommes ejection theory (Thommes et al. 2001), where Uranus and Neptune form near Jupiter and are perturbed into their current locations, has been successfully and extensively tested. An in-depth analysis of the effects planetary ejection has on a system of forming moons is needed to assess the validity of the Thommes model. Using an N-body planetary code, we simulated the formation of gas giant moons in an unperturbed state, absent from proto-planet migration. Satellite formation was also simulated during Thommes ejection, where Uranus and Neptune migrated from near Jupiter’s orbit to their current locations. We propose that the gravitational influences of Uranus and Neptune caused the collapse of Saturn’s satellite disk, resulting in a system of moons dominated by a single body, Titan. We find that in the absence of proto-planet migration, Jupiter and Saturn retain systems of four satellites, similar to the Galilean moons. In 85% of the simulations with planetary ejection, the final satellite configuration for Saturn’s moons closely resembles the present-day Saturn system. The simulations of Jupiter’s moons resulted in Galilean-like systems in ~88% of the unperturbed simulations, while the Thommes ejections simulations were able to recreate the Jupiter family of bodies in only 48% of the simulations. The interactions induced by migrating protoplanets appear to be the cause of Saturn’s single-moon dominated system. To further assess the plausibility of Thommes ejection, we will explore other late-stage formation theories, such as the Nice Model (Tsiganis 2006). 224.09 The Vertical Structure of the Martian Ionosphere Zachary Girazian1, P. Withers1, M. Paetzold2, S. Tellmann2 1Boston University, 2University of Cologne, Germany. 8:00 AM - 7:00 PM Essex Ballroom The vertical structure of the Martian ionosphere consists of two main layers. Maximum electron densities are produced in the M2 layer, which occurs at approximately 140 km, and is created by extreme-ultraviolet solar photons. The weaker M1 layer occurs at approximately 120 km and is produced by solar soft X-rays and associated electron impact ionization. Interpreting the vertical shape of the Martian ionosphere is a key tool for understanding ionosphere behavior and the physical processes involved. The vertical structure of the dayside M2 layer usually consists of a shape similar to idealized Chapman layer theory. However, deviations from this theory are expected as a result of the over-simplified assumptions made by idealized Chapman layer theory. We have investigated 485 vertical electron density profiles from the MaRS radio occultation instrument aboard Mars Express from 2002 to 2010. We will report observations of the vertical structure of the ionosphere of Mars that deviate substantially from the predictions of idealized Chapman layer theory. The examples of unusual M2 layer shapes that we will show include a flat-topped layer, a sharply pointed layer, and a wavy layer. These shapes have not been reproduced by current models of the ionosphere of Mars, which implies significant gaps in our present understanding of the ionosphere of Mars. 224.10 An External Source for Charon’s Atmosphere: Accretion of Pluto’s Atmosphere Prabal Saxena1, M. Summers1 1George Mason University. 8:00 AM - 7:00 PM Essex Ballroom Pluto’s moon Charon may have a significant atmosphere as a consequence of the gravitational capture of Pluto’s extended, escaping atmosphere. Estimates of this capture based process by Charon suggest that it may have a collisionally dominated atmosphere. However, the surface pressure on Charon depends sensitively upon the capture rate and upon Charon’s atmospheric temperature. For the lowest estimate of capture rate, ~ 1.9 x 1024 molecules s-1, based upon Strobel’s Pluto escape rate calculation (Strobel, 2008), Charon will have a collisionally thick atmosphere if its atmospheric temperature is < 50K. For the higher Pluto escape rates of Tian and Toon (2005) of 2.4 x 1025 s-1, Charon will have a collisionally thick atmosphere for atmospheric temperatures < 60K. As we show, observations of Charon’s atmosphere can be used to provide an indirect measure of Pluto’s atmospheric escape rate. 224.11 Attempted Stellar-Occultation Observations for KBO (20000) Varuna on 10 February 2011 Jay M. Pasachoff1, B. A. Babcock1, J. L. Elliot2, M. J. Person2, A. A. S. Gulbis3, C. Zuluaga2, A. Zangari2, W. Rosing4, F. B. Bianco5, J. E. Ciotti6, M. R. Kessler6, S. W. L. Plunkett, Jr.6, N. D. Hiraoka6, K. Mohanan7, E. Pilger8, T. George9, D. Breit10, S. Preston10, K. Lonergan11, S. Menaker12, J. Egger13, M. Lockhart2, M. Gutoski14, P. Rulon14, D. Hampton15, X. Jiang16, J. Bai17, W. P. Chen18, M. Lehner19, J. H. Wang20, Z. W. Zhang20, N. Tokimasa21 1Williams College, 2MIT, 3SALT and MIT, South Africa, 4LCOGT, 5UCSB/LCOGT, 6Windward CC, 7Leeward CC, 8Hawaii Inst. Geophys., 9IOTA/Columbia Basin Col., 10IOTA, 11Wellesley College, 12Anchorage, 13Aeroquest Machining, 14Fairbanks Astron. Unit, 15Fairbanks, 16Beijing Astron. Obs., China, 17Yunnan Astron. Obs., China, 18NCU, Taiwan, 19ASIAA/Penn/CfA, Taiwan, 20TAOS, Taiwan, 21Nishi-Harima Astron. Obs., Japan. 8:00 AM - 7:00 PM Essex Ballroom We attempted to observe the 10 February 2011 occultation of a star of UCAC2 magnitude 15.5 by the Kuiper-belt object (20000) Varuna (visual magnitude 20.2), to determine its size, albedo, and other basic properties. Our original predictions showed the path going between Hawaii and Alaska, but SMARTS astrometry a month before the event moved the prediction 1,646 km north, so we added sites in the northwestern continental US and Alaska. We had clear weather at several sites in the predicted path (Alaska, Pacific Northwest), another site in the 1-sigma path (California), and several sites near the 3-sigma path (Hawaii, China, Taiwan, Japan), though no occultation was detected. Clouds or other problems prevented observations at several other sites. The appulse observations will be used to improve the ephemeris for future Varuna observations. See http://occult.mit.edu/research/occultations/kbo/Varuna/Varuna.20110210/index.html and stellaroccultations.info. This work was supported, in part, by grants NNX10AB27G to MIT and NNX08AO50G to Williams College from NASA's Planetary Astronomy Division. We thank Don Hampton of the Poker Flat Research Range, Alaska, for his assistance. 224.12 Constraints On The Size Of KBO (50000) Quaoar From A Single-chord Stellar Occultation Michael J. Person1, J. L. Elliot1, A. S. Bosh1, A. Zangari1, C. Zuluaga1, T. Brothers1, S. Sallum1, S. Levine2, L. Bright2, S. Sheppard3, T. Tilleman4 1MIT, 2Lowell, 3Carnegie Insitute, 4USNO. 8:00 AM - 7:00 PM Essex Ballroom Observations of the stellar occultation of the magnitude 16.2 star 26029635 UCAC2 (2MASS ID 1275509401) by (50000) Quaoar were made at MIT’s George R. Wallace, Jr., Astrophysical Observatory on the night of 11 February 2011 UT (Sallum, this meeting). A single occultation chord dataset was obtained and will be analyzed to place a lower limit on the size of Quaoar based on this chord. The resulting value will be compared to Quaoar size estimates from other techniques including direct imaging with the Hubble Space Telescope (Brown 2004), and Spitzer Infrared imaging (Stansberry 2007), which give significantly differing results given their error bars (1260 ± 190 km and 844.4 +206.7/-189.6 km, respectively). The difficulties of analyzing low-cadence and single-chord occultation data will be examined, and comparisons to other such occultation chords of this type (e.g. Elliot 2010) will be made. This work is supported in part by grant NNX10AB27G to MIT from NASA’s Planetary Astronomy Division. Student participation is supported in part by NSF's REU program, MIT’s Undergraduate Research Opportunities Program, NASA's Massachusetts Space Grant, and the George R. Wallace, Jr., Astrophysical Observatory. 224.13 First Observations of a Stellar Occultation by KBO (50000) Quaoar from MIT’s George R. Wallace, Jr., Astrophysical Observatory Stephanie Sallum1, T. Brothers1, J. L. Elliot1, M. J. Person1, A. S. Bosh1, A. Zangari1, C. Zuluaga1, S. Levine2, L. Bright2, S. Sheppard3, T. Tilleman4 1MIT, 2Lowell, 3Carnegie Insitute, 4USNO. 8:00 AM - 7:00 PM Essex Ballroom Here we report the first recorded observations of a stellar occultation by Kuiper Belt Object (KBO) (50000) Quaoar. We detected a single-chord stellar occultation by Quaoar of a magnitude 16.2 star designated 26029635 UCAC2 (2MASS ID 1275509401), which occurred on 11 February 2011 UT. The prediction of the occultation was made using long baseline astrometric observations of Quaoar from several sites as part of the MIT Planetary Astronomy Laboratory’s continuing effort to improve KBO positions for occultation prediction. The successful observations were made with a Celestron C14 0.36 m telescope and an SBIG STL-1001E CCD camera on a Paramount ME robotic mount. These observations show that a relatively accessible level of astronomical equipment, of the class often used by amateur astronomers, can be used to record KBO occultations. The data were taken at MIT’s George R. Wallace, Jr., Astrophysical Observatory in Westford, MA. A light curve was generated from the data using aperture photometry on the individual images and is presented here. This light curve is being analyzed by Person et al. (this meeting) to provide constraints on Quaoar’s size. We also discuss various observing strategies that could be used in the future to optimize the data from this type of event. This work was supported in part by grant NNX10AB27G to MIT from NASA’s Planetary Astronomy Division. Student participation was supported in part by NSF's REU program, MIT’s Undergraduate Research Opportunities Program, NASA's Massachusetts Space Grant, and the George R. Wallace, Jr., Astrophysical Observatory. 224.14 An Automated System For Follow-up Of Pan-STARRS NEOs Using The LCOGT Network Tim Lister1 1Las Cumbres Observatory (LCOGT). 8:00 AM - 7:00 PM Essex Ballroom We describe the development of an automated system which can respond to new detections of Near Earth Objects (NEOs) from Pan-STARRS (PS1). The system can automatically download observations of candidate NEOs from Pan-STARRS, compute orbits and observability, find free observation times and schedule observations on the robotic telescopes of the LCOGT network. We present results from the first few months of development and operation and plans for the future with the 6 site, 40 telescope global LCOGT network. 224.15 Monitoring Active Centaurs by Pan-STARRS 1 Hsing-Wen Lin1, Y. Chen1, W. Ip1, M. Holman2, W. Chen1, P. Protopapas2 1Institute of Astronomy, Taiwan, 2Harvard-Smithsonian Center for Astrophysics. 8:00 AM - 7:00 PM Essex Ballroom Centaurs are Solar system small bodies orbiting around the sun between the orbit of Jupiter and Neptune. They are believed to be resupplying the current population of short period comets. About 13% Centaurs show cometary-like activities. However, those active Centaurs never cross the ice-line of solar system; the volatility of water ice hence should not be the triggering source of cometary activity. CO ice is an alternative and has been reported in two Centaurs, but it is too volatile to explain the distribution of measured perihelion. Some other materials had been suggested to be the triggering source of active Centaurs, for example, amorphous ice. To the further investigate of Centaurs activities, a long-term monitoring of large number of Centaurs is initiated with Pan-STARRS 1 data. In this poster we present our method to identify Centaur activity and show early results of 40 known Centaurs from PS1 observations. 224.16 Plasma Heating During Coronal Mass Ejections Nicholas Arnold Murphy1, J. C. Raymond1, K. E. Korreck1 1Harvard-Smithsonian Center for Astrophysics. 8:00 AM - 7:00 PM Essex Ballroom Several recent observational results suggest that coronal mass ejection (CME) plasma is heated even after leaving the flare site. The source of the heating is probably the magnetic field of the erupting flux rope, but the mechanisms that convert magnetic to thermal energy during these events are not well understood. By performing a time-dependent ionization analysis on CMEs observed by SOHO/UVCS, we assess the efficacy of several candidate heating mechanisms, including heating by the CME current sheet, kink/tearing instabilities of the flux rope, turbulence, thermal conduction, energetic particles, and wave heating. 224.17 Temperature Analysis of 171-A Coronal Loops Brian T. Worley1, J. T. Schmelz1 1The University of Memphis. 8:00 AM - 7:00 PM Essex Ballroom We searched the Atmospheric Imaging Assembly (AIA) database for observations of active region coronal loops seen in the 171-A images, which have a peak response temperature of Log T = 5.8. The twelve resulting loops were then analyzed to determine whether the cross-field temperature was isothermal or multithermal. A few of the twelve loops could be recognized as isothermal based on the narrowness of the resulting Differential Emission Measure (DEM) curves. These loops could then be modeled as a single magnetic flux tube. Most of the loops, however, were classified as multithermal as they have relatively broad DEM curves. These loops were more likely composed of several or even many magnetic strands, which might be tangled but are still able to confine plasma of different temperatures. 224.18 Observing Isothermal and Multithermal Coronal Loops using SDO-AIA Sankaet Pathak1, J. Schmelz1 1University of Memphis. 8:00 AM - 7:00 PM Essex Ballroom The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO) is designed to provide an unprecedented view of the solar corona. The six coronal filters peak at different temperatures and cover the entire active region temperature range, making AIA ideal for multi-thermal analysis. Here, we chose several loops in different active regions using images in the 211-A filter, which has a peak response temperature of Log T = 6.3 K. The purpose of this analysis was to determine if the loops were isothermal or multithermal. A few of our 12 loops have narrow temperature distributions, which appear consistent with isothermal plasma. Other loops have intermediate-width temperature distributions and must, therefore, be multi-stranded. The remaining loops have unrealistically broad temperature distributions. However, after a series of tests we found that this problem was the result of missing low-temperature lines in the AIA 131-A channel. We, therefore, repeated the analysis without the 131-A data; these loops then appeared well constrained and multi-stranded. 224.19 Analysis of Full Coronal Loops Observed with the Atmospheric Imaging Assembly Ben Jenkins1, J. Schmelz1 1University of Memphis. 8:00 AM - 7:00 PM Essex Ballroom Using EUV image data from the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory, we have done multi-thermal analysis along the entire length of a collection of coronal loops. The six coronal filters of AIA peak at different temperatures to produce data that span the entire range of temperatures found in these loops. We have selected cooler loops for this analysis that were chosen from images taken with the 171-A filter, which has a peak response temperature around 0.63 MK. The object of this investigation is to determine if the plasma is isothermal or multi-thermal either (a) along the line of sight or (b) along the length of the loop. We have used both an automatic and a manual method to determine the Differential Emission Measure (DEM) distribution at the loop apex and the foopoints. We find that the temperature distribution is narrow, but not consistent with isothermal plasma. In addition, the DEM-weighted temperature changes much less along the loop length than predicted by standard RTV models. 224.20 Differential Emission Measure Analysis of Coronal Loop Data From AIA, EIS, and XRT Jennifer W. Garst1 1Univ. Of Memphis. 8:00 AM - 7:00 PM Essex Ballroom Last year’s launch of the Solar Dynamics Observatory (SDO) has provided additional data to constrain the temperature of coronal loops, allowing for a more detailed analysis of the nature of the heating. Specifically, the high temperature constraints that have been missing from prior analyses are now available to be considered. Images from a coronal loop on the solar disk on December 10, 2010 from both the Atmospheric Imaging Assembly (AIA) and the X-Ray Telescope (XRT) instruments onboard SDO are analyzed along with data from the same date taken by the Extreme Ultraviolet Imaging Spectrometer (EIS) instrument onboard Hinode. Differential emission measure techniques are used to consider whether the loops are isothermal or multithermal in nature. Conclusions regarding the comparison of this data will be presented. Solar physics research at the University of Memphis is supported by NSF ATM-0402729 as well as a Hinode subcontract from NASA/SAO. 224.21 Cross-calibration Of EIS And XRT Using Coronal Bright Points Jason Kimble1, J. T. Schmelz1 1University of Memphis. 8:00 AM - 7:00 PM Essex Ballroom The Extreme Ultraviolet Imaging Spectrometer and the X-Ray Telescope aboard Hinode are designed to complement one another. This study uses X-Ray Bright Points, simple emission features in the Solar Corona, as sources of emission data for the purpose of obtaining a cross-calibration factor for the two instruments. After calibrating and co-aligning the data from each instrument individually, pixels are selected within several coronal Bright Points. By analyzing this equivalent data from both instruments, separate Differential Emission Measures and Emission Measure Loci Plots are produced. These results are then used to produce the desired instrument cross calibrations. The use of Bright Points eliminates the need for prolonged and uncertain background subtraction. Due to the simple thermal characteristics of the Bright Points, this method could be used to calibrate other instruments as well. 224.22 The Solar Rotation and its Evolution During Cycle 23 Sylvain G. Korzennik1, A. Eff-Darwich2 1Harvard-Smithsonian Center for Astrophysics, 2IAC, Spain. 8:00 AM - 7:00 PM Essex Ballroom We present the most exhaustive and accurate inferences of the internal solar rotation rate and its evolution during solar cycle 23. A full solar cycle of MDI observations have been analyzed using our state of the art fitting methodology. Time series of various lengths have been fitted, from a single 4608-day long epoch (64 times 72 day or 12.6 yr) down to 64 separate segments for the "traditional" 72-day long epochs. We used time series of spherical harmonic coefficients computed by the MDI group but using an improved spatial decomposition. This decomposition now includes our best estimate of the image plate scale and of the MDI instrumental image distortion. The leakage matrix used for the fitting includes the distortion of the eigenfunctions by the solar differential rotation, and the undistorted leakage matrix was itself carefully reviewed and independently recomputed. Rotation inversions were carried out for all the available mode sets, fitted for that epoch and all available segments, including the MDI and GONG "pipe-line" sets. The improved inversions we used is an iterative methodology based on a least-squares regularization. It also implement a model grid optimization derived from the actual information in the input set. This optimized model grid is itself irregular, namely with a variable number of latitudes at different depths. We not only present the most accurate mean rotation rate, but also how its derivation may still be affected by uncertainties in the mode fitting (in particular the leakage matrix). We also focus on the change of the rotation rate with activity levels and how well these changes are significantly assessed at higher latitudes as well as deeper in the solar interior, down to the base of the convection zone. 224.23 Dimming of the 17th Century Sun Peter V. Foukal1, A. Ortiz2, R. Schnerr3 1Heliophysics, Inc., 2Institute of Theoretical Astrophysics, University of Oslo, Norway, 3Institute for Solar Physics, Stockholm Observatory, Sweden. 8:00 AM - 7:00 PM Essex Ballroom Reconstructions of total solar irradiance (TSI) rely mainly on linear relations between TSI variation and indices of facular area. When these are extrapolated to the prolonged 15th - 17th century Spörer and Maunder solar activity minima, the estimated solar dimming is insufficient to explain the mid- millennial climate cooling of the Little Ice Age. We draw attention here to evidence that the relation departs from linearity at the lowest activity levels. Imaging photometry and radiometry indicate an increased TSI contribution per unit area from small network faculae by a factor of 2-4 compared to larger faculae in and around active regions. Even partial removal of this more TSI - effective network at prolonged minima could enable climatically significant solar dimming, yet be consistent with the weakened but persistent 11- yr cycle observed in Be 10 during the Maunder Minimum. The mechanism we suggest would not alter previous findings that increased solar radiative forcing is insufficient to account for 20th century global warming. 225 Circumstellar Disks Poster Session Essex Ballroom 225.01 Resolved Images of Large Cavities in Protoplanetary Transition Disks Sean M. Andrews1, D. J. Wilner1, C. Espaillat1, M. Hughes2, K. Dullemond3, M. K. McClure4, C. Qi1, J. M. Brown1 1Harvard-Smithsonian Center for Astrophysics, 2University of California, Berkeley, 3Universitat Heidelberg, Germany, 4University of Michigan. 8:00 AM - 7:00 PM Essex Ballroom We present new and archival high angular resolution Submillimeter Array (SMA) observations of the 880 micron dust continuum emission from 12 transition disks in nearby star-forming regions. In each case, we directly resolve a dust-depleted cavity around the central star. Using two-dimensional Monte Carlo radiative transfer calculations, we interrpret these dust disk structures in a homogeneous, parametric model framework by reproducing their SMA continuum visibilities and spectral energy distributions. The cavities in these disks are large (R = 15-73 AU) and substantially depleted of small (micron-sized) dust grains, although their mass contents are still uncertain. The structures of the remnant material at larger radii are comparable to normal disks. We demonstrate that these large cavities are common among the millimeter-bright disk population, comprising at least 20% of the disks in the bright half of the millimeter luminosity distribution. We suggest that these observations are most commensurate with dynamical clearing due to tidal interactions with low-mass companions - young brown dwarfs of giant planets on long-period orbits. 225.02 Modeling Morphological Structures Observed in Spatially Resolved Scattered Light Images of Protoplanetary Disks John P. Wisniewski1, B. Whitney2, SEEDS Team 1University of Washington, 2University of Wisconsin. 8:00 AM - 7:00 PM Essex Ballroom New near-IR scattered light imagery of young protoplanetary disk systems, imaged by the Strategic Exploration of Exoplanets and Disks with Subaru (SEEDS) survey and other facilities, reveal a wealth of morphological features. We explore the origin of these features using 2D and 3D Monte Carlo radiative transfer simulations, which have been modified to include the effects of inner disk warps, inner disk holes, and spiral structures. Initial comparisons between model runs and observational data will be presented. We acknowledge funding from NSF AST 0802230, NSF AST 1009314, and a Chretien International Research Grant. 225.03 Unraveling the Accretion Disk Spectrum in the Symbiotic Binary R Aquarii Edwin M. Kellogg1, J. DePasquale1, J. Nichols1 1Harvard/Smithsonian CfA. 8:00 AM - 7:00 PM Essex Ballroom R Aquarii is a symbiotic binary with jets and outer thermal lobes. It is known to contain a Mira red giant and its companion is generally believed to be a white dwarf. Here, we analyze the X-ray spectrum of the central binary. We observe several components: a soft thermal source, T ~ 5e6 K, a hard heavily obscured thermal source, T ~ 1.4e8 K, and apparently a complex series of fluorescence lines dominated by Fe Kalpha, but including a series of lines from even Z elements down to C. We compare relative intensities with models of collisional and photo excitation in cool gas. The shape of the Fe Kalpha line may give information on the compactness of the companion. 225.04 Discovery Of Strong Helium 10830A Absorption In The Mid-eclipse Disk Of Epsilon Aurigae Robert E. Stencel1, B. Kloppenborg1, M. Sitko2, J. Rayner3, A. Tokunaga3 1Univ. of Denver, 2Univ. of Cincinnati, 3NASA IRTF. 8:00 AM - 7:00 PM Essex Ballroom During the 2010 eclipse of the enigmatic binary, epsilon Aurigae (F0p + B5?), we obtained a series of near-infrared spectra with the SpeX instrument at NASA's IRTF, primarily to detect the re-appearance of CO (2-0) at 2.29 microns after nominal mid-eclipse, 2010 August 4 (JD 2,454,000). To our surprise, the well-known He I 10830A line appeared in absorption, in the spectrum closest to mid-eclipse (Aug.24, RJD 55433), persisting in spectra Sep.27 (55467), Oct.24 and 29 (55494, 55499). The line weakened by Nov.12 (55513), and was gone Dec.7 (55537) and 2011 Jan.7 (55569). The extra absorption, up to 6A equivalent width, appeared atop a weaker, persistent 1A equivalent width feature. With Van de Kamp's distance (580 pc) and orbital velocities during eclipse phase, the duration of the extra absorption implies a region 1.0 +/- 0.2 AU in radial extent, in the middle of the eclipse-causing dark disk with its 3.8 +/- 0.2 AU radius. He I 10830 arises from a metastable triplet from a lower level at 19.82 volts, representing plasma in excess of 25,000K. If the disk-center star were B5V type and experiencing a modest amount of accretion, it would create a 1 AU Stromgren He+ sphere. This assumes a mean gas density of 10$^{10}$ cm$^{-3}$, which is the lower limit to the column density established by non-detection of soft Xrays. This heated region could represent the presence of an upper main sequence object and accretion onto the hidden star inside the disk, in analogy to Be stars, symbiotics, zeta Aurs and YSOs. This work was supported in part by the bequest of William Herschel Womble in support of astronomy at the University of Denver, by NSF grant 1016678 and JPL RSA 1414715 to the University of Denver, and by NASA ADP grant NNX09AC73G to the University of Cincinnati. 225.05 Accretion in the Disk of epsilon Aurigae: Results of Monte Carlo Radiative Transfer Modelling Naomi Pequette1, R. Stencel1, B. Whitney2 1University of Denver, 2Space Science Institute. 8:00 AM - 7:00 PM Essex Ballroom Epsilon Aurigae is a mysterious eclipsing binary system that has been observed for more than 175 years. Current theory remains undecided whether the system is made up of a massive F-supergiant star and an equally massive, but hidden, companion, or a post-AGB F-star and a binary companion made up of a B5V which is surrounded by a transitional or debris disk. We used a Monte Carlo Radiative Transfer Model (MCRTM, written by Barbra Whitney of the Space Sciences Institute) to model the B-star and surrounding disk. By using this model, our goal was to reproduce the observed Spectral Energy Distribution (SED, Hoard, Howell and Stencel, HHS, 2010) of the B-star and disk components of the epsilon Aurigae System. Our initial parameters utilized the results of HHS. The initial run of MCRTM did not result in matching the observed SED. Subsequently, we explored previously unknown disk parameters, most importantly disk mass and accretion rate. We found that to reproduce the observed 10:1 ratio of IR to Far-UV flux, we must have a non-zero rate of accretion occuring in the disk. To avoid depleting the disk too quickly, our simulations find that a more massive disk becomes too opaque due to increased scattering and does not reproduce the observed SED. Thus, we propose the extra mass might be in the form of planetesimals. The high accretion rate also implies dust mass replinishment, possibly due to a high rate of collisional interaction among planetesimals embedded in the disk. This work was supported in part by the bequest of William Herschel Womble in support of astronomy at the University of Denver, by NSF grant 1016678 and JPL RSA 1414715 to the University of Denver. 225.06 Hydrodynamic Simulations of Algol Systems with Tilted Accretion Disks Eric Raymer1, J. Blondin1 1North Carolina State University. 8:00 AM - 7:00 PM Essex Ballroom Recent observational data has shown that the Algol-type binary system RS Vul possesses an accretion disk tilted out of the orbital plane. Magnetic effects in the surface of the donor star could produce a nontrivial effect in the flow of the accretion stream as it travels through the L1 Lagrange point. Such a deflection could introduce angular momentum with a non-z component that could propagate toward the primary and lead to a tilted accretion disk. We use three-dimensional hydrodynamic simulations of the mass transfer and accretion disk in RS Vul to investigate this hypothesis. 225.07 Dynamics and Evolution of Self-Gravitating Circumstellar Disks on a Moving Mesh Diego Munoz1, L. Hernquist1 1Harvard University. 8:00 AM - 7:00 PM Essex Ballroom We present a novel approach to the numerical study of gas disks around young stars using the Voronoi-tessellation cosmological code AREPO (Springel,2010). This finite-volume code is shock-capturing and second-order-accurate in time and space. Its moving mesh makes it a Lagrangian/Eulerian code that satisfies Galilean invariance and has a very low diffusivity due to its unbiased unstructured grid. Its pseudo-Lagrangian nature makes it ideal for problems that show large dynamical range in density, such as gravitationally unstable systems with clustering and collapse. The self-gravity solver is implemented consistently for collisionless particles as well as for gas ``particles" (Voronoi cells) in an N-body fashion using a tree algorithm. The hydrodynamics+N-body approach of AREPO is unparalleled in its ability to treat self-gravitating systems that lack of a symmetric configuration while retaining the resolution and accuracy of conventional grid codes. Thus, it combines the benefits of both particle- and mesh-based codes. Precisely, these two approaches are used in numerical studies of circumstellar disks depending on the physical process of interest. For example, those studies that choose particle based codes -- such as SPH -- focus on gravitationally unstable disks or the tidal interaction of disks. On the other hand, grid codes are preferred in studies of planet-disk interaction, where proper treatment of shocks, wakes and gaps requires an accurate shock-capturing method. We present examples of how the flexible approach of AREPO can be used to simulate these and other types of problems. 226 Young Stellar Objects, Very Young Stars, T-Tauri Stars, H-H Objects Poster Session Essex Ballroom 226.01 Near-Infrared Variability in Young Stars with Disks Thomas Rice1, S. J. Wolk1, C. Aspin2 1Harvard-Smithsonian Center for Astrophysics, 2University of Hawaii Institute for Astronomy. 8:00 AM - 7:00 PM Essex Ballroom We present the results from the analysis of 120 epoch time-series photometry of a 1 square degree region of the Lynds 1003 dark cloud in the Cygnus OB7 association. Using the Wide-Field imaging camera (WFCAM) on UKIRT we were able to obtain almost-nightly J,H,K' photometry over three observing seasons of over 100,000 stars with photometric uncertainty better than 0.02 mag in the range J=10-16 mags and better than 0.1 mag down to J=18. We have identified over 300 candidate disk-bearing YSOs from color criteria and have investigated variability and periodicity for these stars relative to the field population. We have uncovered a population of young stars whose K-band infrared excess varies significantly over our 2-year observations. We report the discovery of periodic and stochastic variables among T Tauri stars, and present rotation periods for a number of YSOs. Part of this work was funded by the NSF REU program. 226.02 Catching the Weak T-Tauri Population in L1641 North and NGC 1980. Ignazio Pillitteri1 1SAO. 8:00 AM - 7:00 PM Essex Ballroom The complex of Orion Molecular Cloud is the most interesting example of complex cloud and star forming region. With SOXS program we have obtained information on the X-ray (with XMM-Newton) and infrared (IR, with Spitzer) of the young population distributed along NGC1980 and L1641 south of the Orion Nebula Cloud. In the framework of studying dynamics and morphology of star forming regions, we have conducted an optical spectroscopic follow-up of 37 bona fide Weak-T-Tauri stars in NGC1980/L1641 North, selected on the basis of their strong X-ray emission and the absence of IR excesses in Spitzer IRAC bands. Here we present radial velocities, H-alpha and Lithium equivalent widths and discuss these in the context of their spatial distribution information obtained with IR and X-ray observations. 226.03 Accretion Variability in Young Spectroscopic Binaries David R. Ardila1, G. Herczeg2, C. Johns-Krull3, M. Robert4 1NASA Herschel Science Center / IPAC / Caltech, 2Max Planck Institute for Extraterrestrial Physics, Germany, 3Rice University, 4University of Wisconsin at Madison. 8:00 AM - 7:00 PM Essex Ballroom In this project, we study circumbinary disk accretion into young binaries as a function of orbital phase. We have observed the pre-main-sequence binaries UZ Tau E (mass ratio q=0.3, e=0.33) and DQ Tau (q=1, e=0.58) in four phases, over three orbital periods, with the Hubble Space Telescope (COS), and rougly simultaneously with the NASA Infrared Telescope Facility (CSHELL), McDonald Observatory (Sandiford Echelle), and the Gemini Observatory (GNRIS). Here we present preliminary results from the HST observations. We observe dramatic variability in the CIV (1550 A) doublet in both stars and in the accretion rate as a function of phase. The DQ Tau system shows strong changes in the CIV line shape and centroid, and increased accretion at apastron, as manifested in the NUV flux. In the UZ Tau E system the CIV line develops a redshifted (~50 km/sec) emission at moments of strong accretion. The changes are not completely consistent with previous (optical) observations, as they seem dominated not by the orbital period but by stochastic changes in accretion. They serve to illuminate the geometry of the accretion flow in young binaries. 226.04 Near-infrared Variability Of Young Stellar Objects In The YSOVAR Program Joseph L. Hora1, J. Stauffer2, M. Morales-Calderon2, J. Carpenter2, J. Bloom3, D. Starr3, YSOVAR Team 1Harvard-Smithsonian CFA, 2Caltech, 3University of California - Berkeley. 8:00 AM - 7:00 PM Essex Ballroom The Spitzer Young Stellar Object variability (YSOVAR) project is currently underway and to date has obtained well-sampled light curves for several star forming regions, including fields in Orion, IC 1396, Mon R2, NGC 2264, Ceph-C, L1688, IRAS 20050+2720, and GGD 12-15. The survey will eventually contain data for over 2000 YSOs, and will allow us to place constraints on the structure of the inner disks, measure the stability of hot spots on the surfaces of YSOs over a range of evolutionary stages, and determine rotational periods for a large sample of objects. As part of this project, we have obtained contemporaneous near-infrared (JHK) photometry of the fields using the PAIRITEL telescope. We have continued the near-IR monitoring to assess the stability of the YSOs over longer periods. We will present initial results from the PAIRITEL observations, including a comparison of the JHK and IRAC 3.6 and 4.5 micron variability, and the long-term behavior of the YSOs. 226.05 Inner Structure in the TW Hya Circumstellar Disk Rachel L. Akeson1, R. Millan-Gabet1, D. Ciardi1, A. Boden2, A. Sargent2, J. Monnier3, H. McAlister4, T. ten Brummelaar4, J. Sturmann4, L. Sturmann4, N. Turner4 1NASA Exoplanet Science Institute, Caltech, 2Dept of Astronomy, Caltech, 3University of Michigan, 4CHARA, Georgia State University. 8:00 AM - 7:00 PM Essex Ballroom TW Hya is a nearby (50 pc) young stellar object with an estimated age of 10 Myr and signs of active accretion. Previous modeling of the circumstellar disk has shown that the inner disk contains optically thin material, placing this object in the class of "transition disks". We present new near-infrared interferometric observations of the disk material and use these data, as well as previously published, spatially resolved data at 10 microns and 7 mm, to constrain disk models based on a standard flared disk structure. Our model demonstrates that the constraints imposed by the spatially resolved data can be met with a physically plausible disk but this requires a disk containing not only an inner gap in the optically thick disk as previously suggested, but also some optically thick material within this gap. Our model is consistent with the suggestion by previous authors of a planet with an orbital radius of a few AU. This work was conducted at the NASA Exoplanet Science Institute, California Institute of Technology. 226.06 Examining Star-Disk interactions in Pre-Main Sequence Binaries: A Submillimeter Array Survey of Taurus Multiple Star Systems Robert J. Harris1, S. M. Andrews1 1Harvard University. 8:00 AM - 7:00 PM Essex Ballroom Most stars are born in multiple systems. Theory predicts that star-disk interactions in these systems preferentially strip circumstellar disk material away from the lower-mass companion, such that the ratio of the companion disk radius to orbital separation is set by the orbital parameters of the system. To test those predictions, we present a comparison of disk mass as a function of orbital separation and stellar mass ratio using a new, resolved 880 micron Submillimeter Array (SMA) imaging survey of young multiple star systems in Taurus (for stellar mass ratios > 0.1 and separations > 35 AU). We also highlight some initial results from complementary EVLA radio-wave observations of some of these disk-bearing multiple systems, and comment on how they can be used to quantify how dust coagulation in their disks compares with those around isolated stars. 226.07 The Anatomy of the Young Protostellar Outflow HH 211: Strong Evidence for CO v = 1-0 Fundamental Band Emission from Dense Gas in the Terminal Shock Achim Tappe1, J. Forbrich1, S. Martín2, C. J. Lada1 1Harvard-Smithsonian Center for Astrophysics, 2European Southern Observatory, Chile. 8:00 AM - 7:00 PM Essex Ballroom We present Spitzer Space Telescope 5-37 µm spectroscopic mapping observations toward the southeastern lobe of the young protostellar outflow HH 211 (part of IC 348 in Perseus, 260 pc). The terminal shock of the outflow shows a rich atomic and molecular spectrum with emission lines from OH, H2O, HCO+, CO2, H2, HD, [Fe II], [Si II], [Ne II], [S I], and [Cl I]. The spectrum also shows a rising continuum towards 5 µm, which we interpret as unresolved emission lines from highly excited rotational levels of the CO v=1-0 fundamental band. This interpretation is confirmed by a strong excess flux observed in the Spitzer IRAC 4-5 µm channel 2 image. We also observed the terminal outflow shock of this lobe with the Submillimeter Array (SMA) and detected pure rotational emission from CO 2-1, HCO+ 3-2, and HCN 3-2. The rotationally excited CO traces the collimated outflow and the terminal shock, whereas the vibrationally excited CO seen with Spitzer follows the continuation of the collimated outflow backbone in the terminal shock. The extremely high critical densities of the CO v=1-0 rovibrational lines indicate terminal shock jet densities larger than 107 cm-3. The unique combination of mid-infrared, submillimeter, and previous near-infrared observations allow us to gain detailed insights into the interaction of one of the youngest known protostellar outflows with its surrounding molecular cloud. Our results help to understand the nature of some of the so-called ‘green fuzzies’ (Extended Green Objects) identified by their Spitzer IRAC channel 2 excess and association with star-forming regions. They also provide a critical observational test to models of pulsed protostellar jets. 226.08 Optical And Infrared Monitoring Of KH 15D Holly Capelo1, W. Herbst1, C. Hamilton2 1Wesleyan Uniersity, 2Dickinson College. 8:00 AM - 7:00 PM Essex Ballroom We present the most recent optical and near-infrared photometric monitoring of KH15D, a pre-main sequence binary star system that undergoes occultation by a precessing high-inclination circumbinary disk. Amplitude variations in the object's periodic light curve may be accounted for by the dependence of reflectance properties of the disk on distance from the binary or by a putative third body within the system. We have acquired medium-resolution spectra intended to probe circumstellar absorption features for signatures of mineral condensates for our study of this object's proto-planetary environment. 226.09 Simultaneous Spitzer/Chandra Observation Of Young Stellar Objects In GGD 12-15 - Do X-ray Flares Produce Disk Afterglows? Jan Forbrich1, K. R. Covey2, S. J. Wolk1, J. R. Stauffer3, R. R. A. Gutermuth4, M. Morales Calderon3, B. A. Whitney5, J. L. Hora1, B. Posselt6 1Harvard-Smithsonian CfA, 2Cornell University, 3Caltech, 4Smith College, 5Space Science Institute, 6Pennsylvania State University. 8:00 AM - 7:00 PM Essex Ballroom We present first results of a simultaneous 20h Spitzer/Chandra monitoring campaign of the young cluster GGD 12-15. By analyzing correlated X-ray and mid-IR variability on different timescales, we are testing 1) theoretical predictions of X-ray heating in circumstellar disks (in an analogy to reverberation mapping), and 2) whether disk accretion rates rise following stellar X-ray flares, as expected from disk accretion models. Focusing on simultaneous X-ray and mid-infrared observations and timescales of minutes to hours, this project is leveraging extensive mid-IR light curves obtained via the Spitzer Warm Mission program YSOVAR. Ancillary science includes the identification of weak-line T Tauri stars to study their mid-IR variability and the LX-rotation relation of protostars, using mid-IR periods. 227 Results From Kepler Poster Session Essex Ballroom 227.01 Using the Kepler February 2011 Data Release to Estimate the Frequency of Planets Courtney D. Dressing1 1Harvard University. 8:00 AM - 7:00 PM Essex Ballroom In February 2011, the Kepler team announced the discovery of 1235 planet candidates. The majority of the candidates have radii smaller than Neptune and orbital periods less than fifty days. Although these data are preliminary and some candidates may prove to be astrophysical false positives, this sample of planet candidates is large enough to probe the underlying distribution of planets as a function of planetary radius, semimajor axis, and host star spectral type. We approach this problem by considering a variety of underlying distributions and assigning planets according to those distributions to the stars listed in the Kepler Input Catalog. We simulate the likelihood of detecting a transit of each planet around its assigned host star, accounting for the geometric probability of transit, the transit duration, and the number of transits that would be observed during the first year of the Kepler mission assuming square root of N improvement with the number of transits. We require a signal to noise ratio of 7 for detection as required by the Kepler team for inclusion in the list of Kepler Objects of Interest in the February data release, and we reject any underlying distribution of planets that differs significantly from the Kepler data. CDD acknowledges support from the National Science Foundation Graduate Research Fellowship Program. 227.02 Starspots And Spin-orbit Alignment In the Wasp-4 Exoplanetary System Roberto Sanchis Ojeda1, J. N. Winn1, M. J. Holman2, J. A. Carter2, D. J. Osip3, C. I. Fuentes4 1MIT, 2Cfa - Harvard, 3Las Campanas Observatory, Chile, 4Northern Arizona University. 8:00 AM - 7:00 PM Essex Ballroom We present photometry of 4 transits of the exoplanet WASP-4b, each with a precision of approximately 500 ppm and a time sampling of 40-60s. During two of the transits we observed a short-lived, low-amplitude anomaly that we interpret as the occultation of a starspot by the planet. We also find evidence for a pair of similar anomalies in previously published photometry. The recurrence of these anomalies suggests that the stellar rotation axis is nearly aligned with the orbital axis, or else the star spot would not have remained on the transit chord. By analyzing the timings of the anomalies we find the sky-projected stellar obliquity to be 1^{+12}_{-14} degrees. This result is consistent with (and more constraining than) a recent observation of the Rossiter-McLaughlin effect. It suggests that the planet migration mechanism preserved the initially low obliquity, or else that tidal evolution has realigned the system. We discuss future applications of this method using data from the Kepler satellite, which will allow spin-orbit alignment to be probed for many other exoplanets. 227.03 Following up Kepler Objects of Interest Using Adaptive Optics Images Elisabeth R. Adams1, A. K. Dupree1, C. Kulesa2, D. W. McCarthy2, Kepler Science Team 1SAO, 2U. of Arizona. 8:00 AM - 7:00 PM Essex Ballroom With the recent announcement of over 1200 candidate transiting planets, the Kepler space mission has an enormous need for high-quality follow-up observations, both to confirm the planetary nature of its candidates and to accurately measure their characteristics. The pixel size for Kepler images is just under 4", which means that close companion stars could dilute the signal from the target star, leading to an underestimate of the planetary parameters, or even a false positive detection. High-resolution images are thus vital to either detect potential contaminants or to rule out their presence with high confidence. Here we present images taken by ARIES, a near-infrared PI instrument using adaptive optics on the MMT. When operated in the f/30 mode, images are 20" x 20" and have a resolution of 0.02" per pixel. During the 2009-2010 seasons of Kepler follow-up, 37 Kepler Objects of Interest, or KOIs, were imaged with ARIES; 11 of them had at least one companion within 2" of the target star, the closest having a separation of only 0.15". We show images of various companion stars and describe the limits placed on objects by magnitude difference and separation. We will also discuss how these companion stars affect the parameters as determined by Kepler 227.04 Kepler Observations of Pulsations In A Sample of Magnetically-Active Stars James E. Neff1, A. Brown2, S. Hawley3, A. Kowalski3, L. Walkowicz4, S. Saar5 1College of Charleston, 2CASA/University of Colorado, 3University of Washington, 4University of California/Berkeley, 5Harvard/Smithsonian Center for Astrophysics. 8:00 AM - 7:00 PM Essex Ballroom We have observed about 200 targets in Kepler Cycle 1/2 Guest Observer programs. The sample of active star candidates was selected primarily using GALEX colors, and the Kepler light curves have revealed a rich variety of variability. Rotational modulation (typical periods a few days) due to starspots over the multi-year timeline of the Kepler observations will permit us to measure surface differential rotation and stellar magnetic cycles. On shorter timescales, the Kepler data show dramatic evidence of stellar pulsations across much of the HR diagram. Our selection criteria yielded a sample of magnetically active G and K dwarfs, which might show solar-like pulsations. It also yielded subsamples of several well-known pulsators (e.g., Delta Scuti stars) as well as pulsators that currently defy easy classification. We are systematically classifying and analyzing the pulsating stars in the our Kepler GO program. We are particularly interested in using pulsations to probe the interior properties of active G and K dwarfs, while the starspots serve as a probe of the convection zone and surface layers. We will present summary results for several different types of pulsation, and we will provide a detailed asteroseismic analysis of those stars in our sample that were observed to have both pulsations and magnetic activity. This work contains results obtained using the NASA Kepler satellite and from the Apache Point Observatory, the MMT (using NOAO community access time), and the Hobby-Eberly Telescope. Funding is provided by NASA Kepler grants NNX10AC51G and NNX11AC79G. 227.05 High Cadence Kepler Observations of Flare Stars Suzanne L. Hawley1, A. F. Kowalski1, J. P. Wisniewski1, E. J. Hilton1, L. M. Walkowicz1, A. Brown2 1Univ. of Washington, 2Univ. of Colorado. 8:00 AM - 7:00 PM Essex Ballroom We report on preliminary results from our Kepler Cycle 2 GO program to observe low mass stars at high cadence (one observation per minute). The outstanding fidelity of the Kepler light curves reveals both starspot modulation and a large number of stellar flares. We investigate the flare amplitude, frequency and energy distributions and relate these to the better-known nearby flare stars in the solar neighborhood. 227.06 NGC 6811: An Intermediate-age Cluster In The Kepler Field Kenneth Janes1, S. Barnes2, S. Meibom3, S. Hoq1 1Boston Univ., 2Lowell Observatory, 3Center for Astrophysics. 8:00 AM - 7:00 PM Essex Ballroom NGC 6811 is one of four open clusters located in the Kepler spacecraft field of view. We have observed the cluster on several occasions with the 1.08-meter Hall and 1.83-meter Perkins telescopes at Lowell Observatory. A well-defined main sequence and red giant "clump" are clearly visible in the color-magnitude diagram; several of the red clump stars have velocities consistent with cluster membership. We have analyzed the data from two photometric nights (one night with each telescope) and we derive the following parameters for the cluster: E(B-V) = 0.04 ± 0.04, (m-M)o = 11.0 ± 0.2 and log(age) = 9.05 ± 0.10, all assuming a slightly metal-poor composition. We are continuing our analysis with additional photometry. 227.07 Application of an Empirical Bayesian Technique to Systematic Error Correction and Data Conditioning of Kepler Photometry Jeffrey C. Smith1, J. M. Jenkins1, J. E. Van Cleve1, J. Kolodziejczak2, J. D. Twicken1, M. C. Stumpe1, M. N. Fanelli3 1SETI Institute/NASA Ames Research Center, 2NASA Marshall Space Flight Center, 3Bay Area Environmental Research Institute. 8:00 AM - 7:00 PM Essex Ballroom We present a Bayesian Maximum A Posteriori (MAP) approach to systematic error removal in Kepler photometric data, in which a subset of highly correlated stars is used to establish the range of “reasonable” robust fit parameters, and hence mitigate the loss of astrophysical signal and noise injection on transit time scales (<3d), which afflict Least Squares (LS) fitting. A numerical and empirical approach is taken where the Bayesian Prior PDFs are generated from fits to the light curve distributions themselves versus an analytical approach, which uses a Gaussian fit to the Priors. Along with the systematic effects there are also Sudden Pixel Sensitivity Dropouts (SPSDs) resulting in abrupt steps in the light curves that should be removed. A joint fitting technique is therefore presented that simultaneously applies MAP and SPSD removal. The concept will be illustrated in detail by applying MAP to publicly available Kepler data, and give an overview of its application to all Kepler data collected through the present. We show that the light curve correlation matrix after treatment is diagonal, and present diagnostics such as correlation coefficient histograms, singular value spectra, and principal component plots. The benefits of MAP is shown applied to variable stars with RR Lyrae, harmonic, chaotic, and eclipsing binary waveforms, and examine the impact of MAP on transit waveforms and detectability of transiting planets. We conclude with a discussion of current work on selecting input vectors for the design matrix, generating the Prior PDFs and suppressing high-frequency noise injection with Bandpass Filtering. Funding for this work is provided by the NASA Science Mission Directorate. 228 12-Years of Science with Chandra Poster Session Essex Ballroom 228.01 The X-ray Variability of Capella Jennifer Posson-Brown1, V. Kashyap1 1Smithsonian Astrophysical Observatory. 8:00 AM - 7:00 PM Essex Ballroom Capella is an unusual coronal source. It is an active binary with a G8 III clump giant primary and a G1 III gap giant secondary, and has an emission measure distribution that shows a strong high-temperature component. However, it does not display rapid variability signatures like flares. It has been observed at X-ray wavelengths by Chandra over a decade of calibration observations, and here we describe our analysis using multiple instruments on Chandra (205 ks with HRC-I, 581 ks with HRC-S/LETG, and 388 ks with ACIS-S/HETG) to characterize the variability at timescales ranging from minutes to hours to weeks to years. We study both the overall intensity variations as well as variations at different temperatures, as manifested in spectral lines. We detect no flares over a megasecond of observations. But we find that variability at the 10% level is present at all temperatures and at all timescales. In particular, we find that the high temperature plasma is more strongly variable than the low temperature plasma. This work was supported by CXC NASA contract NAS8-39073. 228.02 X-ray binaries in Young Massive Clusters Sanghamitra Goswami1, F. A. Rasio1 1Northwestern University. 8:00 AM - 7:00 PM Essex Ballroom We present the theoretical predictions for X-ray binary observations in young stellar environments, such as starbursts and young star clusters. Using a Monte Carlo method, we model realistic star clusters with ≈ 5 × 105 stars and significant binary fractions. Our code includes the physics of stellar and binary evolution, direct integration of close interactions, physical stellar collisions and tidal mass loss. Using this code we compute the formation rates and characteristic properties of single and binary BHs for various representative ages and choices of parameters. We find that, in general, more single BHs are formed and also retained in clusters, than BHs in binaries. We also find that the ejection of BHs from the cluster is a function of density, binary fraction and the number of stars in the cluster. For example, in low density clusters, it is mainly the initial supernovae kicks which eject BHs (low-mass stellar BHs) from the cluster, whereas in high density clusters more BHs (both low and high-mass stellar BHs) are ejected with dynamics. This leads us to speculate that the population of X-ray binaries in the vicinity of star clusters, is mainly from dense and massive clusters. We also use a stellar evolution code to calculate the luminosity of BH binaries ejected from the cluster and investigate the possibility of getting an observable X-ray binary from the cluster. 228.03 Focused Wind Mass Accretion in Mira AB Margarita Karovska1, M. de Val-Borro2, W. Hack3, J. Raymond1, D. Sasselov4, N. P. Lee1 1Harvard Smithsonian, CfA, 2Max Planck Institute, Germany, 3STScI, 4Harvard University. 8:00 AM - 7:00 PM Essex Ballroom At a distance of about only 100pc, Mira AB is the nearest symbiotic system containing an Asymptotic Giant Branch (AGB) star (Mira A), and a compact accreting companion (Mira B) at about 0.5" from Mira A. Symbiotic systems are interacting binaries with a key evolutionary importance as potential progenitors of a fraction of asymmetric Planetary Nebulae, and SN type Ia, cosmological distance indicators. The region of interaction has been studied using high-angular resolution, multiwavelength observations ranging from radio to X-ray wavelengths. Our results, including high-angular resolution Chandra imaging, show a "bridge" between Mira A and Mira B, indicating gravitational focusing of the Mira A wind, whereby components exchange matter directly in addition to the wind accretion. We carried out a study using 2-D hydrodynamical models of focused wind mass accretion to determine the region of wind acceleration and the characteristics of the accretion in Mira AB. We highlight some of our results and discuss the impact on our understanding of accretion processes in symbiotic systems and other detached and semidetached interacting systems. 228.04 Using Chandra Hetg And Swift Xrt Spectra To Understand Cygnus X-3 R. Petri Savolainen1, M. L. McCollough1, D. C. Hannikainen2 1Smithsonian Astrophysical Observatory, 2Aalto University Metsähovi Radio Observatory, Finland. 8:00 AM - 7:00 PM Essex Ballroom The energy resolving power of Chandra HETG substantially exceeds that of Swift XRT, by a factor of ~5 around 6 keV. In the case of the High-Mass X-ray Binary Cygnus X-3, prominent emission lines, P-Cygni profiles and Radiative Recombination Continua readily apparent in Chandra grating spectra blend together in XRT spectra, showing up as residuals to the continuum that resemble wide absorption and emission features. These occur most consistently in the range of 1.8-3.5 keV (3.5-6.9 Angstrom). We investigate the use of a model derived from non-simultaneous Chandra HETG observations to fit these residuals in the Swift XRT spectra. 228.05 Probing Cygnus X-3's "Little" Friend Michael L. McCollough1 1Harvard-Smithsonian, CfA. 8:00 AM - 7:00 PM Essex Ballroom Using Chandra's unparalleled spatial resolution a discovery of an unique feature related to Cygnus X-3 has been made. The feature is a region of extended emission located 16" from the microquasar. The feature has been found to exhibit the same 4.8 hour flux modulation shown by Cygnus X-3. From a study of the spectra, flux and time variations of this feature we believe we are observing the scattering of X-ray emission from Cygnus X-3 by a dust cloud located along our line of sight. From these Chandra observations we are able to deduce the location, size, and properties of this cloud. We also find that this cloud appears to be part of a larger structure possibly associated with Cygnus X-3. We will present this analysis and examine some of its ramifications. 228.06 No Confirmed New Isolated Neutron Stars in the SDSS Data Release 4 Marcel A. Agueros1, B. Posselt2, S. F. Anderson3, P. Rosenfield3, F. Haberl4, L. Homer3, B. Margon5, E. R. Newsom1, W. Voges4 1Columbia University, 2Harvard-Smithsonian Center for Astrophysics, 3University of Washington, 4Max-Planck-Institut für extraterrestrische Physik, Germany, 5University of California-Santa Cruz. 8:00 AM - 7:00 PM Essex Ballroom We report on follow-up observations of candidate X-ray bright, radio-quiet isolated neutron stars (INSs) identified from correlations of the ROSAT All-Sky Survey (RASS) and the Sloan Digital Sky Survey (SDSS) Data Release 4 in Agüeros et al. (2006). We obtained Chandra X-ray Telescope exposures for 13 candidates in order to pinpoint the source of X-ray emission in optically blank RASS error circles. These observations eliminated 12 targets as good INS candidates. We discuss subsequent observations of the remaining candidate with the XMM-Newton X-ray Observatory, the Gemini North Observatory, and the Apache Point Observatory. We identify this object as a likely extragalactic source with an unusually high log(fX/fopt) ~ 2.4. We also use an updated version of the population synthesis models of Popov et al. (2010) to estimate the number of RASS-detected INSs in the SDSS Data Release 7 footprint. We find that these models predict ~3 - 4 INSs in the 11,000 square deg imaged by SDSS, which is consistent with the number of known INSs that fall within the survey footprint. In addition, our analysis of the four new INS candidates identified by Turner et al. (2010) in the SDSS footprint implies that they are unlikely to be confirmed as INSs; together, these results suggest that new INSs are not likely to be found from further correlations of the RASS and SDSS. 228.07 A Complete Sample of ULX Host Galaxies Douglas A. Swartz1, A. F. Tennant2, R. Soria3, M. Yukita4 1USRA/MSFC, 2NASA/MSFC, 3MSSL/UCL, United Kingdom, 4UA Tuscaloosa. 8:00 AM - 7:00 PM Essex Ballroom One hundred seven ultraluminous X-ray (ULX) sources with 0.3-10.0 keV luminosities in excess of 1e39 erg/s are identified in a complete sample of 127 nearby galaxies. The sample includes all galaxies within 14.5 Mpc above the completeness limits of both the Uppsala Galaxy Catalog and the Infrared Astronomical Satellite survey. This represents the least-biased ULX host galaxy sample to date. The galaxy sample spans all Hubble types and a range of four decades in mass and in star-formation rate. ULXs are detected in this sample at a rate of 0.5 per 1e10 solar masses and 2.7 per solar mass/year star-formation rate. At these rates we predict as many as 15 additional ULXs remain undetected in fainter dwarf galaxies within the survey volume. Less than 13 of the 107 ULX candidates are expected to be background interlopers. Properties of the sample galaxies and a census of the ULX candidate population are presented. 228.08 On the Plerionic Supernova Remnant CTB 87 (G74.9+1.2) and Its Powering Engine: Insights from the Chandra X-ray Observatory Samar Safi-Harb1, H. Matheson1, R. Kothes2 1Univ. of Manitoba, Canada, 2DRAO/NRC/HIA, Canada. 8:00 AM - 7:00 PM Essex Ballroom Pulsar Wind Nebulae (PWNe) offer a valuable astrophysical laboratory to study the physics of pulsar winds and their interaction with the ISM, and to search for missed pulsars. While the Crab nebula has been known for decades to represent the prototype of PWNe, there are several PWNe whose properties differ from the Crab, leading to a class dubbed as `plerions of a second kind’. CTB 87 (G74.9+1.2) belongs to this class and is one of the least studied members in X-rays. In the radio, it has a low-frequency spectral break and an unusually steep spectral index hinting to an evolved PWN. We present an archival ASCA observation of this object and a new 70 ksec ACIS-I Chandra observation dedicated to resolve the putative pulsar and to perform a high-resolution imaging and spectroscopic study of the PWN, including the search for structures associated with the deposition of the neutron star’s energy into its surroundings. The peak of X-ray emission is clearly offset from the radio peak. For the ASCA data, a power-law model fit yields a column density of (1.14±0.22)x1022 cm-2, a photon index of 1.77±0.15, and a luminosity of ~1.4x1034 erg s-1 (at the revised distance of 6.1kpc). Thanks to Chandra, the source powering the nebula is resolved and its spectrum is studied separately from the PWN. Both are well described by a power law model with a hard photon index. The Chandra source-the putative pulsar- is found at the south-eastern edge of the bright radio nebula, with jet-like and diffuse emission from the PWN extending to the northwest. We discuss our X-ray study in correlation with recent sensitive radio continuum and polarization measurements obtained with the CGPS and Effelsberg. Finally, we compare G74.9+1.2 to other PWNe likely in a similar stage of their evolution, including G63.7+1.1, G65.7+1.2, and G76.9+1.0. 228.09 X-ray and Optical Emission Correlations in the Shocked Ejecta in Cassiopeia A Daniel Patnaude1, R. A. Fesen2 1Harvard-Smithsonian, CfA, 2Dartmouth College. 8:00 AM - 7:00 PM Essex Ballroom We present multi-epoch X-ray and optical observations of the ejecta in the Galactic supernova remnant Cassiopeia A. We discuss the evolution of the emissions from the remnant's shocked ejecta as seen in optical using broadband, ground-based and Hubble Space Telescope images and Chandra ACIS X-ray images and compare the morphology of these emissions at both similar and differing epochs. Using a hydrodynamical model of the supernova remnant's reverse shock, we compare the structure and spectral evolution of the ejecta's optical and X-ray emissions to detailed multidimensional models for the evolution of the shock and the nonequilibrium ionization in the ejecta. 228.10 The Chandra Carina Complex Project: Introduction and Diffuse X-ray Emission Leisa K. Townsley1, CCCP Team 1Penn State Univ.. 8:00 AM - 7:00 PM Essex Ballroom The Great Nebula in Carina provides an exceptional view into the violent massive star formation and feedback that typifies giant HII regions and starburst galaxies. We have mapped the Carina star-forming complex in X-rays, using archival Chandra data and a mosaic of 20 new 60-ks ACIS-I pointings, as a testbed for understanding recent and ongoing star formation and to probe Carina's regions of bright diffuse X-ray emission. This study has yielded a catalog of properties of >14,000 X-ray point sources; >9800 of them have multiwavelength counterparts. Using Chandra's unsurpassed X-ray spatial resolution, we have separated these point sources from the extensive, spatially-complex diffuse emission that pervades the region; X-ray properties of this diffuse emission suggest that it traces feedback from Carina's massive stars. Line-like correlated residuals in the diffuse emission spectral fits suggest that substantial X-ray emission is generated by charge exchange at the interfaces between Carina's hot, rarefied plasma and its many cold neutral pillars, ridges, and clumps. 228.11 The Chandra Carina Complex Project: Finding Oases in the X-Ray Desert of Intermediate-Mass Stars Matthew S. Povich1 1Penn State University. 8:00 AM - 7:00 PM Essex Ballroom The Chandra Carina Complex Project, coupled with complementary infrared observations, has revealed the young stellar population of the Great Nebula in Carina in unprecedented detail. Compared to previous studies of nearby, less massive clusters, these datasets provide a far richer sample of young, intermediate-mass (IM; 1.6--8 Msun) stars. In X-ray studies of young star clusters, two paradigms are currently favored by observation and theory: (1) IM stars occupy an X-ray-quiet "desert" between magnetically active low-mass stars and massive stars with strong stellar winds. (2) Among low-mass, pre-main-sequence (PMS) stars, X-ray luminosity is lower among classical T Tauri stars with circumstellar disks compared to weak-lined T Tauri stars. We have compiled a catalog of 1439 predominantly IM young stellar objects (YSOs) identified via infrared excess emission in the CCCP field, 410 of which were also detected by Chandra. In most cases, the X-ray emission is consistent with the presence of an unresolved, lower-mass companion to the infrared source, but we also find that X-ray emission correlates with cooler stellar photospheres and higher disk masses. This result appears to violate paradigm (1), while reversing paradigm (2) for the case of IM stars. X-ray emission appears to be intrinsic to IM stars during their early PMS evolution, perhaps driven by magnetic dynamo activity during the convective atmosphere phase, but this emission dies off as the stars approach the main sequence. Such a model predicts that the observed power-law slope of the X-ray luminosity function in a young star cluster steepens with age over timescales of a few Myr. M.S.P. is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-0901646. 228.12 A Deep Chandra Legacy Observation of the Nearby Grand Design Spiral M83 Knox S. Long1, L. Bianchi2, W. P. Blair2, P. Ghavamian1, K. D. Kuntz2, P. P. Plucinsky3, R. Soria4, P. F. Winkler5 1STScI, 2JHU, 3SAO, 4Curtin Institute of Radio Astronomy, Australia, 5Middlebury College. 8:00 AM - 7:00 PM Essex Ballroom With a high supernova rate, a starburst nucleus, and large numbers of high mass star clusters in the disk of the galaxy, M83 is a superb laboratory for understanding how the life cycle of stars and the interstellar medium interact to produce X-ray emission in normal galaxies. Here we report initial results of a set of ongoing deep Chandra ACIS observations of M83 that will ultimately have a total exposure of 750 ks. Our preliminary catalog, based on the first 160 ks of data, includes more than 180 sources, a number that will likely grow by a factor of 2 when the observations are complete. New sources include a new ultraluminous X-ray source that has appeared in an interarm region since the earlier Chandra observations in 2001, as well as the X-ray counterpart to the SN 1957D. Many of the sources are coincident with supernova remnant candidates identified from new interference filter images of M83 from Magellan/IMACS. We will discuss how we intend to relate the X-ray properties of the supernova remnants, X-ray binaries, and diffuse X-ray emission to the local environment, using the underlying stellar populations and/or distance from features like the spiral arms to constrain the progenitors of the sources. We gratefully acknowledge support for this project by NASA through grant GO1-12115A. 228.13 Chandra ACIS Survey of M33 (ChASeM33): The Final Source Catalog Paul P. Plucinsky1, R. Tuellmann1, T. J. Gaetz1, K. D. Kuntz2, B. F. Williams3, K. S. Long4, ChASeM33 Team 1Harvard-Smithsonian, CfA, 2Johns Hopkins University, 3University of Washington, 4Space Telescope Science Institute. 8:00 AM - 7:00 PM Essex Ballroom We present the final point source catalog of the Chandra ACIS Survey of M33 (ChASeM33). With a total exposure time of 1.4 Ms, ChASeM33 covers ~70% of the D25 isophote (R~4.0 kpc) of M33 and provides the deepest, most complete, and detailed look at a spiral galaxy in X-rays. The source catalog includes 662 sources (~half in M33), reaches a limiting unabsorbed luminosity of 2.4e34 erg/s in the 0.35-8.0 keV band (assuming an NH of 1e21 cm^-2), and contains source positions, source net counts, fluxes and significances in several energy bands, and information on source variability. The source catalog and additional information are available at: "http://hea-www.harvard.edu/vlp_m33_public/chasem33_fincat.html". To constrain the nature of the detected X-ray source, hardness ratios were constructed and spectra were fit for 254 sources, followup MMT spectra of 116 sources were acquired, and cross-correlations with previous X-ray catalogs and other multi-wavelength data were generated. Based on this effort, 183 of the 662 ChASeM33 sources could be identified. Finally, the luminosity function for the detected point sources as well as for the X-ray binaries in M33 is presented. The luminosity functions in the soft band (0.5-2.0 keV) and the hard band (2.0-8.0 keV) have a limiting luminosity at the 90% completeness limit of 4.0e34 erg/s and 1.6e35 erg/s (for D=817 kpc), respectively, which is significantly lower than previous X-ray binary population studies in galaxies more distant than M33. The resulting distribution is consistent with a dominant population of high mass X-ray binaries as would be expected for M33. This work was supported by NASA grant NAS G06-7073A and NASA contract NAS8-03060. 228.14 An X-ray Imaging Survey of Quasar Jets -- Testing the Inverse Compton Model Herman L. Marshall1, J. M. Gelbord2, D. A. Schwartz3, D. W. Murphy4, J. E. J. Lovell5, D. M. Worrall6, M. Birkinshaw6, E. S. Perlman7, L. Godfrey8, D. L. Jauncey9 1MIT, 2PSU, 3SAO, 4JPL, 5U. Tasmania, Australia, 6U. Bristol, United Kingdom, 7FIT, 8Curtin U. of Tech., Australia, 9CSIRO, Australia. 8:00 AM - 7:00 PM Essex Ballroom We present results from continued Chandra X-ray imaging of a flux-limited sample of flat spectrum radio-emitting quasars with jet-like extended structure. X-rays are detected from 24 of the 39 jets observed so far. We compute the distribution of α_rx, the spectral index between the X-ray and radio bands, showing that it is broad, extending at least from 0.8 to 1.2. While there is a general trend that the radio brightest jets are detected most often, it is clear that predicting the X-ray flux from the radio knot flux densities is risky so a shallow X-ray survey is the most effective means for finding jets that are X-ray bright. We test the model in which the X-rays result from inverse Compton (IC) scattering of cosmic microwave background (CMB) photons by relativistic electrons in the jet moving with high bulk Lorentz factor nearly along the line of sight. Depending on how the jet magnetic fields vary with z, the observed X-ray to radio flux ratios do not follow the redshift dependence expected from the IC-CMB model. For a subset of our sample with known superluminal motion based on VLBI observations, we estimate the angles of the kpc-scale jets to the line of sight by considering the additional information in the bends observed between pc- and kpc-scale jets. These angles are sometimes much smaller than estimates based on the IC-CMB model with a Lorentz factor of 15, indicating that these jets may decelerate significantly from pc scales to kpc scales. Support for this work was provided in part by the NASA through the Smithsonian Astrophysical Observatory (SAO) contract SV3-73016 to MIT for support of the Chandra X-Ray Center, which is operated by SAO for and on behalf of NASA under contract NAS8-03060. 228.15 A Chandra and XMM-Newton Study of the Hot Gas Filament in the Centaurus A Northern Middle Radio Lobe Ralph P. Kraft1, W. Forman1, P. Nulsen1, M. Hardcastle2, M. Birkinshaw3, C. Jones1, J. Croston4, D. Worrall5, S. Murray6 1Harvard-Smithsonian, CfA, 2University of Hertfordshire, United Kingdom, 3Bristol University, United Kingdom, 4University of Southampton, United Kingdom, 5University of Bristol, United Kingdom, 6Johns Hopkins University. 8:00 AM - 7:00 PM Essex Ballroom We present preliminary results from our 70 ks Chandra/ACIS-S observation of the X-ray filament of thermal gas embedded in the Centaurus A Northern Middle Radio lobe (NML). Our previous XMM-Newton observations showed that this filament was composed of five extended knots connected with diffuse emission. We attributed this hot gas filament to the interaction of the currently active NML with cold gas that had been stripped from a dwarf galaxy and is probably the best example of a radio galaxy jet/cold cloud interaction. With the Chandra data, we find two important new results. First, we find that the temperature of the filament varies between 0.3 and 0.7 keV, and that the abundance is roughly half Solar. Second, there are no sharp discontinuities in the emission that would be indicative of shocks. The implications of thse results for our understanding of jet-cloud interactions will be discussed. 228.16 X-ray Absorption Variability In Ngc 4507 Andrea Marinucci1, G. Risaliti1, M. Elvis1, S. Bianchi2, G. Matt2 1SAO, 2Roma 3 University, Italy. 8:00 AM - 7:00 PM Essex Ballroom We present a complete spectral analysis of an XMM-Newton and Chandra campaign of the obscured AGN in NGC 4507, consisting of six observations spanning a period of six months. We detect strong absorption variability on time scales between 1.5 and 4 months, suggesting that the obscuring material consists of gas clouds at parsec-scale distance. The lack of variability on shorter time scales rules out the possibility of absorption by broad line region clouds, which was instead found in other studies of similar sources. This shows that a single, universal structure of the absorber (either BLR clouds, or the parsec-scale torus) is not enough to reproduce the observed complexity of the X-ray absorption features of AGNs. 228.17 AGN Variability in the 4 Ms Chandra Deep Field-South Monica Young1, N. Brandt1, Y. Xue1, B. Luo1, CDF-S Team 1Pennsylvania State University. 8:00 AM - 7:00 PM Essex Ballroom The 4Ms Chandra Deep Field-South (CDF-S) Catalog is ideally suited to explore long-term variability in AGN and galaxies. Variability is a powerful tool for detecting AGN in “galaxy”-like sources, and spectral variability is capable of providing significant insight into AGN structure. We explore flux and spectral variability over month to year timescales by dividing the CDF-S observations into four epochs, each approximately 1Ms in duration: 2000, 2007, 2010a (March-May), and 2010b (May-July). Main results: 1) We confirm that most AGN with sufficient statistics are variable - AGN variability increases with net counts to >70% variability in sources with total net counts greater than 300. 2) A significant fraction of sources classified as “galaxies” exhibit AGN-like variability, up to 60% in sources with greater than 25 net counts, including a number of “optically bright, X-ray faint” (OBXF) galaxies. 3) Spectral variability is common, and exhibits a variety of behaviors relative to flux. We will discuss these results with respect to AGN structure and demographics. 228.18 An In-depth Chandra ACIS View Of The Circumnuclear Region Of NGC 4151: The Jet, The Biconical Outflow, And A Leaky Torus Junfeng Wang1, G. Fabbiano1, M. Elvis1, G. Risaliti2, M. Karovska1, A. Zezas3, C. G. Mundell4 1Harvard-Smithonian CfA/SAO, 2INAF, Italy, 3University of Crete, Greece, 4Liverpool John Moores University, United Kingdom. 8:00 AM - 7:00 PM Essex Ballroom We report on the imaging analysis of 200 ks Chandra ACIS-S observations of the nearby Seyfert 1 galaxy NGC 4151. Structured soft X-ray emission is observed to extend from 30 pc to 1.5 kpc. We find strong evidence for jet-gas cloud interaction in the inner 150 pc region, confirming our previous HRC results. Self-consistent photoionization models provide good descriptions of the spectra of the optical bi-cone, supporting the dominant role of nuclear photoionization. Presence of both low and high ionization spectral components and extended emission in the X-ray image perpendicular to the bi-cone indicates leakage of nuclear ionization. Using spatially resolved features, we estimate the kinematic power of the outflow in NGC 4151 to be 0.3% of its bolometric luminosity. This work is supported by NASA grant GO8-9101X and GO1-12009X. 228.19 The Environmental Impact Of The High-redshift (z=1.532) Radio-loud Quasar 3c270.1 Belinda J. Wilkes1, D. Lal1, D. M. Worrall2, M. Birkinshaw2, M. Haas3, P. Barthel4, S. Willner1, M. Ashby1, C. Leipski5 1Harvard-Smithsonian, CfA, 2University of Bristol, United Kingdom, 3Astronomisches Institut, Ruhr-University, Germany, 4Kapteyn Institute, Netherlands, 5MPIA, Germany. 8:00 AM - 7:00 PM Essex Ballroom Chandra X-ray observations of the high-redshift (z=1.532) radio-loud quasar 3C 270.1 taken in Feb 2008 show the nucleus to have a typical power-law spectrum with a weak, 170 eV, Fe Kα emission line. The data also reveal extended emission, about half of which is associated with the strong radio emission from this source while the remainder appears more diffuse. The radio-related X-ray emission is soft, consistent with inverse-Compton emission from an aging electron population. The southern emission is co-spatial with the radio lobe and peaks at the position of the double radio hotspot. Modelling of this hotspot with the inclusion of Spitzer upper limits rules out synchrotron emission from a single power-law population of electrons, favoring inverse-Compton emission (SSC) with a field of 20 nT, 45% below equipartition. The northern emission is concentrated close to the location of a 40 deg. bend where the radio jet is presumed to encounter the ICM. It can be explained by iC/CMB emission with a field of 5 nT, 20% of the equipartition field. The remaining, more diffuse emission is harder (HR=-0.09+/-0.22). With only 22.8+/-5.6 counts, the spectral form cannot be constrained. If we assume thermal emission, and a temperature of 4 keV, we estimate a luminosity of 1.8E44 erg/s, consistent with the luminosity- emperature relation of lower-redshift clusters. However deeper Chandra X-ray observations are equired to delineate the spatial distribution, better constrain the spectrum of the diffuse emission and so confirm/not the presence of X-ray emission from a cluster. 228.20 The Role of Shock Heating in AGN Feedback: A Case Study of the Galaxy Group NGC 5813 Scott W. Randall1, W. Forman1, S. Giacintucci2, P. Nulsen1, M. Sun3, C. Jones1, E. Churazov4, L. David1, R. Kraft1, M. Donahue5, E. Blanton6, A. Simionescu7, N. Werner7 1Center for Astrophysics, 2University of Maryland, 3University of Virginia, 4Max-Planck-Institut fur Astrophysik, Germany, 5Michigan State University, 6Boston University, 7KIPAC. 8:00 AM - 7:00 PM Essex Ballroom We present results from new Chandra, GMRT, and SOAR observations of NGC5813, the dominant central galaxy in a nearby galaxy subgroup. The system shows clear signatures from three distinct outbursts of the central AGN, with three pairs of roughly collinear cavities. The inner two cavity pairs are each associated with elliptical shock fronts with measured temperature jumps and Mach numbers of M~1.7 and M~1.5 for the inner and outer shocks, respectively. Such clear signatures from three distinct AGN outbursts in an otherwise relaxed system provide a unique opportunity to study AGN feedback and outburst history. The mean power of the two most recent outbursts varies by an order of magnitude, indicating that the mean jet power varies significantly over long (~10^7 yr) timescales. The total energy output of the most recent outburst is also less than the total energy of the previous outburst, which may be a result of the lower mean power, or may indicate that the most recent outburst is ongoing. We directly measure the local heat input into the ICM at the shock fronts, and show that the shock heating balances radiative cooling of the gas locally. The outburst interval implied by both the shock and cavity ages (~10^7 yr) indicates that in this system shock heating alone is sufficient to balance radiative cooling close to the central AGN, which is the relevant region for regulating feedback between the ICM and the central SMBH. 228.21 Probing The Outskirts Of Galaxy Clusters With Chandra, Suzaku, And XMM Eric D. Miller1, J. George2, D. Davis3, M. W. Bautz1, R. P. Mushotzky2, J. P. Henry4 1MIT, 2U. Maryland, 3NASA/GSFC, 4U. Hawaii. 8:00 AM - 7:00 PM Essex Ballroom The outskirts of galaxy clusters, beyond R_500, remain relatively unexplored territory and yet are vital to our understanding of cluster growth, structure, and mass. We present the first results from a program to constrain the state of the outer intra-cluster medium (ICM) in a large sample of galaxy clusters, exploiting the strengths of three complementary X-ray observatories: Chandra (good spatial resolution), Suzaku (low background), and XMM-Newton (high sensitivity). By carefully combining observations from the cluster core to beyond R_200, we are able to identify and and reduce systematic uncertainties that would impede our spatial and spatial analysis using a single telescope. Our initial sample comprises six clusters fully covered in azimuth to beyond R_200, and our analysis indicate that the ICM is not in hydrostatic equilibrium in the cluster outskirts, where we see clear azimuthal variations in temperature and surface brightness. We also describe plans to triple the size of our cluster sample, an improvement that will allow us to probe clusters exhibiting both falling and flat temperatures profiles. 228.22 Sloshing, Shocks, and Bubbles in the Cool Core Cluster Abell 2052 Elizabeth L. Blanton1, S. W. Randall2, T. E. Clarke3, C. L. Sarazin4, B. R. McNamara5, E. M. Douglass1, M. McDonald6 1Boston University, 2Harvard-Smithsonian Center for Astrophysics, 3Naval Research Laboratory, 4University of Virginia, 5University of Waterloo, Canada, 6University of Maryland. 8:00 AM - 7:00 PM Essex Ballroom We present results from a very deep (650 ksec) Chandra X-ray observation of Abell 2052, as well as archival VLA radio observations. The data reveal exquisite detail in the inner parts of the cluster, including bubbles evacuated by the AGN’s radio lobes, compressed bubble rims, filaments, and loops. Two concentric shocks are seen, and a temperature rise is measured for the innermost one. On larger scales, an excess surface brightness spiral feature is detected. The spiral has cooler temperatures and higher abundances than its surroundings, and is likely the result of sloshing gas initiated by a previous cluster-cluster or sub-cluster merger. Initial evidence for previously unseen bubbles at larger radii related to earlier outbursts from the AGN is presented. Support for this work was provided by the National Aeronautics and Space Administration, through Chandra Award Number GO9-0147X. 228.23 Cosmological Constraints from Galaxy Cluster Gas-Mass Fractions: the Latest from Chandra Adam Mantz1, S. W. Allen2, R. G. Morris2 1NASA Goddard Space Flight Center, 2Stanford University. 8:00 AM - 7:00 PM Essex Ballroom Gas mass fractions of massive, dynamically relaxed clusters, measured through X-ray observations, are a powerful tool for measuring cosmic distances, and have provided strong constraints both on the mean dark matter density and on dark energy. I will present preliminary results from such a study, which employs various modeling improvements and uses approximately twice as much Chandra data as previous work. 228.24 Chandra Probe of the Missing Baryons Taotao Fang1, D. Buote1, P. Humphrey1, C. Canizares2 1Univ. of California-Irvine, 2MIT. 8:00 AM - 7:00 PM Essex Ballroom I will discuss how the recent Chandra observations of X-ray absorption lines help address the "missing baryons" problem. 228.25 ACIS Thermal Control and Observing Strategies Nancy Adams-Wolk1, T. Aldcroft1, P. P. Plucinsky1, G. Germain1 1Harvard-Smithsonian, CfA. 8:00 AM - 7:00 PM Essex Ballroom Nearing its 13th observing cycle, the Chandra X-Ray Observatory continues to deliver excellent science to the High Energy community. The orbit of Chandra, and thermal conditions of the spacecraft and instruments have changed over time which has necessitated changes in observing strategies; particularly for the ACIS instrument. This poster focuses on expected changes to be implemented in Cycle 13 for observing with the ACIS instrument. We will focus on the thermal issues with ACIS, including warming of the PSMC, DEA, and Focal Plane. We discuss the causes of the warming of these components of ACIS based on past data, and how this warming can affect observations. Trending studies have strongly suggested changes to the future observing strategies for ACIS. We discuss these changes which include reducing the number of CCDs powered on for temperature sensitive observations, implementing an ACIS FP temperature model to predict temperatures based on spacecraft pitch and pointing, and the use of optional CCDs to reduce the number of CCDs during the planning of a particular week. 228.26 The ACIS Instrument On The Chandra X-ray Observatory: Instrument Status And Performance Evolution Catherine E. Grant1, ACIS instrument team 1MIT. 8:00 AM - 7:00 PM Essex Ballroom After more than twelve years in orbit, the ACIS instrument on the Chandra X-ray Observatory continues to perform well. The response of ACIS has evolved over the lifetime of the observatory. We will present the current status of the ACIS instrument, some results from the instrument team's monitoring program and our expectations for the future. 228.27 Enhanced Wavdetect: Carrying Out Source Detection In Multi-look Observations Vinay Kashyap1, J. Drake1, N. Wright1, T. Aldcroft1 1Harvard Smithsonian, CfA. 8:00 AM - 7:00 PM Essex Ballroom A fundamental limitation of current source detection algorithms is that they can only run on one observation dataset at a time. We have developed an enhancement to CIAO WAVDETECT that lets us to carry out source detection on combined datasets from multiple overlapping looks at the same region with different pointings. This improves the sensitivity of surveys, and allows us to detect weak sources in the full dataset that are below the detection threshold in each of the individual observations. Our method properly corrects for the varying sizes of the PSF, and thus limits the false detection rate. We have applied this to a mosaic of multiple observations of CygOB2. We find that this process increases the number of detected sources by approximately 10% over standard runs of WAVDETECT. This work was supported by CXC NASA contract NAS8-39073. 228.28 X-ray Constraints on the Lyman Alpha Escape Fraction Zhenya Zheng1, S. Malhotra1, J. Wang2, J. Rhoads1, S. Finkelstein3, E. Gawiser4, C. Gronwall5, L. Guaita6, K. Nilsson7, R. Ciardullo5 1Arizona State University, 2University of Science and Technology of China, China, 3Texas A&M University, 4The State University of New Jersey, 5Penn State University, 6Universidad Catolica de Chile, Chile, 7European Southern Observatory, Germany. 8:00 AM - 7:00 PM Essex Ballroom We use coadded X-ray flux of all known Lyman alpha emitters in Chandra Deep Field South using the 4 megasecond image, to place sensitive upper limits on the average unobscured star-formation rate (SFR) in these galaxies. A very small fraction of Lyman alpha emitter galaxies in the field are detected in the X-rays, implying a low fraction of AGN activity. After excluding the few X-ray detected Lyman alpha emitters (LAEs), we stack the undetected LAEs located in the 4 Ms CDF-S data and 250 ks ECDFS data, and get the 1 sigma upper limit on SFR_X 14% (84 % confidence level) for LAEs at redshift z ~ 2.1 and z ~ 3.2. At z > 4, we do not have large enough LAE samples to constrain SFR_X well. By averaging all the LAEs at z > 2, the X-ray non-detection constrains f^{Ly-alpha}_{esc} > 17% (84 % confidence level), and reject f^{Ly\alpha}_{esc} < 5.7% at 99.87% confidence level. We also compare the X-ray properties of the Lyman Break galaxies in the same fields. 228.29 Young X-ray Binary Populations in Low Metallicity Star-Forming Galaxies Vallia Antoniou1, A. Zezas2, V. Kalogera3 1Iowa State University, 2Smithsonian Astrophysical Observatory, 3Northwestern University. 8:00 AM - 7:00 PM Essex Ballroom We present an investigation of the connection between spatially resolved star-formation and the young (<100 Myr) X-ray Binary (XRB) populations in the Small and the Large Magellanic Clouds, our two nearest star-forming galaxies, using X-ray and optical photometric and spectroscopic data. For the Small Magellanic Cloud we find that the High-Mass XRBs are observed in regions with star-formation rate bursts ~25-60 Myr ago, while for the Large Magellanic Cloud we find that these populations are concentrated in regions as young as ~13-50 Myr. The similarity of this age with the age of maximum occurrence of the Be phenomenon (~40 Myr) indicates that the presence of a circumstellar decretion disk plays a significant role in the number of observed XRBs in the 10-100 Myr age range. We discuss the effect of age and metallicity in the relative number of Be-XRBs in the two galaxies in comparison with the Milky Way, and with predictions of population synthesis models for sub-solar metallicity galaxies. 228.30 Chandra ACIS Sub-pixel Resolution Dong-Woo Kim1, C. S. Anderson1, A. E. Mossman1, G. E. Allen2, G. Fabbiano1, K. J. Glotfelty1, M. Karovska1, V. L. Kashyap1, J. C. McDowell1 1Smithsonian Astrophysical Observatory, 2MIT Kavli Institute for Astrophysics and Space Research. 8:00 AM - 7:00 PM Essex Ballroom We investigate how to achieve the best possible ACIS spatial resolution by binning in ACIS sub-pixel and applying an event repositioning algorithm after removing pixel-randomization from the pipeline data. We quantitatively assess the improvement in spatial resolution by (1) measuring point source sizes and (2) detecting faint point sources. The size of a bright (but no pile-up), on-axis point source can be reduced by about 20-30%. With the improve resolution, we detect ~20% more faint sources when embedded on the extended, diffuse emission in a crowded field. We further discuss the false source rate of about 10% among the newly detected sources, using a few ultra-deep observations. We also find that the new algorithm does not introduce a grid structure by an aliasing effect for dithered observations and does not worsen the positional accuracy 228.31 Edges, Bubbles And Shocks In The Dominant Elliptical Galaxy Ngc5846 Marie E. Machacek1, R. Kraft1, D. Jerius1, C. Jones1, W. R. Forman1, S. Randall1, S. Giacintucci2, M. Sun3 1Smithsonian Astrophysical Obs., 2University of Maryland, 3University of Virginia. 8:00 AM - 7:00 PM Essex Ballroom NGC 5846, one of the best examples of a dominant elliptical galaxy in a nearby galaxy group, gives us the opportunity for a simultaneous study of the dynamics of non-hydrostatic gas motions induced by galaxy interactions, AGN activity and bubble evolution. We use a combined 120 ks Chandra exposure to analyze the X-ray edges and cavities produced by these dynamical processes. From analysis of the edges we constrain the orbit of the perturbing interaction and the gas velocities. We use the properties of the observed cavities to constrain the AGN outburst duty cycle and outburst energetics. We argue that the properties of the inner bubbles are consistent with the recent passage of a shock. We also present the first observation of ram pressure stripping of a compact elliptical galaxy, NGC 5846A, during its supersonic infall towards the dominant group elliptical galaxy NGC 5846. 228.32 The HETG Orion Legacy Project Norbert S. Schulz1, D. P. Huenemoerder1, C. R. Canizares1, P. Testa2, J. Nichols2, A. Mitschang3 1MIT, 2SAO, 3Macquarie University, Australia. 8:00 AM - 7:00 PM Essex Ballroom The ONC is an ideal astrophysical laboratory to study very young stars. The HETG Orion Legacy Project is designed to obtain a large number of high-resolution X-ray spectra of very young late type pre-main sequence stars, and several young massive and intermediate mass stars. Its extreme proximity and youth makes the core of the ONC a Chandra legacy project involving the only high resolution spectroscopic study of young embedded cluster stars for decades to come. We present new results for the second most massive star θ 2 Ori A, the intermdiate mass binary θ 1 Ori E, and six late-type stars including MT Ori and LQ Ori. 229 Black Holes Poster Session Essex Ballroom 229.01 The Halo Occupation Distribution of Black Holes Colin DeGraf1, M. Oborski1, T. Di Matteo1, S. Chatterjee2, D. Nagai2, J. Richardson2, Z. Zheng2 1Carnegie Mellon University, 2Yale University. 8:00 AM - 7:00 PM Essex Ballroom Using hydrodynamic cosmological simulations that directly follow black hole growth we investigate the halo occupation distribution (HOD) of black holes. Similar to the HOD of galaxies/subhalos, we find that the black hole occupation number can be described by the power law N_BH proportional to 1+(M_Host)^α where α evolves mildly with redshift, indicating that a given mass halo at low redshift tends to host fewer BHs than at high redshift (as expected as a result of galaxy and BH mergers). We further show how to divide the occupation number into contributions from black holes residing in central and satellite galaxies within the halo. The distribution of black holes masses and luminosities within halos tends to consist of a single massive, bright BH (distributed about a peak mass strongly correlated with the host mass), and a collection of relatively low-mass secondary BHs with weaker correlation to host mass. We examine the spatial distribution of black holes within their host halos, and find they typically follow a power-law radial distribution that is much more centrally concentrated than the subhalo distribution. We further show that black hole feedback becomes increasingly important at low redshifts, which can lead to suppression of the central quasar luminosity and increased scatter in the correlation between quasar luminosity and host halo mass. Overall, this HOD formalism provides the most complete tool for characterizing the distribution of black holes within host halos and galaxies, and can be used in semi-analytic and theoretical models and as a framework for interpreting observational black hole measurements. 229.02 Quasi-spherical, Time-dependent Viscous Accretion Flow With High Viscosity Seong-Jae Lee1, D. Ryu2, I. Chattopadhyay3, S. Hyung1 1Chungbuk National University, Korea, Republic of, 2Chungnam National University, Korea, Republic of, 3ARIES, India. 8:00 AM - 7:00 PM Essex Ballroom We reported the results of the time-dependent simulations of large amplitude oscillations of advective, viscous, sub-Keplerian disks with a proper trement of angular momentum transfer in one-dimensional, quasi-spherical transonic accretion flow around a non-rotating black hole using the Lagrangian Total Variation Diminising (TVD) and a remap routine.Our code has a shock-capturing capability better than both standard Eulerian code and Lagrangian SPH code. It could well follow the angular momentum transfer of the viscous, subsonic, analytical solution. Hence, we present a simulation of a rotating, viscous, transonic fluid with shocks. Oscillation of the accretion shock was produced due to the different rates of angular momentum transfer across the shock and the heat dissipated due to the presence of high viscosity parameter. Moreover, as the shock drifts to larger distances, a secondary inner shock develops. We showed that the inner shock is the direct consequence of expansion of the outer shock, as well as creation of regions with dl / dr < 0 due to more efficient angular momentum transfer near the inner sonic point. The oscillatory motion of the shock induced oscillation in all the disk parameters such as emission, rate of matter consumed by the black hole, and the rate of angular momentum consumed by the black hole. Our simulation may have implication for low and high frequency QPOs. 229.03 Measuring Black-Hole Spin and Modeling the Jet Dynamics in Microquasar XTE J1550-564 James F. Steiner1, J. E. McClintock1 1Harvard-Smithsonian Center for Astrophysics. 8:00 AM - 7:00 PM Essex Ballroom The microquasar XTE J1550-564 produced the very first X-ray jets to be observed from a black-hole X-ray binary. Chandra imaging data obtained for these jets during 2000-2003 offer a near-unique opportunity to test whether the black hole's spin axis is tilted or aligned with respect to the plane of the binary orbit. To this end, we apply a kinematic relativistic blast-wave model to position measurements of the expanding jet. A comparison of the derived orientation of the jet to the optically measured binary inclination angle has important implications for the measurement of black hole spin. We present our results in the context of ongoing studies of the spins of several black holes, including XTE J1550-564. 229.04 The Local Environments of Ultra-Luminous X-Ray Sources in Interacting Galaxies Beverly Smith1, O. Miller1, M. Nowak2, C. Struck3 1East Tennessee State Univ., 2Massachusetts Institute of Technology, 3Iowa State University. 8:00 AM - 7:00 PM Essex Ballroom In the last several years, the Chandra X-Ray Observatory has discovered hundreds of ultra-luminous X-ray (ULX) point sources in nearby galaxies. These may be either intermediate mass (100 - 1000 solar mass) black holes or stellar mass black holes with anisotropic X-ray emission. To help distinguish between these possibilities, we are conducting a statistical analysis of the local environments of a sample of several hundred ULXs in nearby interacting galaxies. Using GALEX UV, SDSS optical, and Spitzer IR images, we investigate the stellar populations within the galaxies in the local vicinity of the ULXs. We also investigate whether the ULXs are more likely to be found in tidal features or in the inner disks of these galaxies. This research is supported by NASA Chandra grant AR9-0010A. 229.05 Long Term Monitoring of Black Hole Binaries with SMARTS Charles D. Bailyn1, M. Buxton1 1Yale Univ.. 8:00 AM - 7:00 PM Essex Ballroom We have been monitoring black hole X-ray binaries (BHXRBs) for over ten years with the SMARTS consortium telescopes (and its precursor YALO) at CTIO. We will present lightcurves of a variety of well-known systems including A0620-00, GX 339-4, V4641 Sgr (=SAX 1819-2525), GRO J1915+105, GRO J1655-40 and others. The use of the ANDICAM instrument allows us to monitor these sources in both optical and IR bandpasses. We show that it is possible in many cases to divide the observed flux between flux from the secondary star and flux from the accretion flow, and in some cases between thermal emission from the accretion flow and a non-thermal component that presumably originates in a jet. 229.06 Evidence for Black Hole Growth in Local Analogs to Lyman Break Galaxies Jianjun Jia1, A. Ptak2, T. M. Heckman1, R. A. Overzier3, A. Hornschemeier2, S. M. LaMassa1 1The Johns Hopkins University, 2Goddard Space Flight Center, 3Max-Planck Institute for Astrophysics, Germany. 8:00 AM - 7:00 PM Essex Ballroom We have used XMM-Newton to observe six Lyman Break Analogs (LBAs): members of the rare population of local galaxies that have properties that are very similar to distant Lyman Break Galaxies. Our six targets were specifically selected because they have optical emission-line properties that are intermediate between starbursts and Type 2 (obscured) AGN. Our new X-ray data provide an important diagnostic of the presence of an AGN. We find X-ray luminosities of order 10^{42} erg/s and ratios of X-ray to far-IR luminosities that are higher than values in pure starburst galaxies by factors ranging from ~3 to 30. This strongly suggests the presence of an AGN in at least some of the galaxies. The ratios of the luminosities of the hard (2-10 keV) X-ray to [O III]5007 emission-line are low by about an order-of-magnitude compared to Type 1 AGN, but are consistent with the broad range seen in Type 2 AGN. Either the AGN hard X-rays are significantly obscured or the [O III] emission is dominated by the starburst. We searched for an iron emission line at 6.4 keV, which is a key feature of obscured AGN, but only detected emission at the 2\sigma level. Finally, we find that the ratios of the mid-infrared (24 micron) continuum to [O III] luminosities in these LBAs are higher than the values for Type 2 AGN by an average of 0.8 dex. Combining all these clues, we conclude that an AGN is likely to be present, but that the bolometric luminosity is produced primarily by an intense starburst. If these black holes are radiating at the Eddington limit, their masses would lie in the range of 10^5 to 10^6 solar masses. These objects may offer ideal local laboratories to investigate the processes by which black holes grew in the early universe. 229.07 Testing General Relativity with the Event Horizon Telescope Jessica Ruprecht1, T. Johannsen2, V. L. Fish3, A. E. Broderick4, S. S. Doeleman3, A. Loeb5, A. E. E. Rogers3 1MIT, 2University of Arizona, 3MIT Haystack Observatory, 4CITA, Canada, 5Harvard CFA. 8:00 AM - 7:00 PM Essex Ballroom General relativity (GR) predicts that light near a black hole will be lensed so as to produce a nearly circular photon orbit at a well-defined radius around the black hole. When embedded in an accretion flow, the emission profile will resemble all or part of a ring with a dark "shadow" within the photon orbit. Detecting the size and shape of a black hole shadow would serve as a test of GR. In particular, significant deviation from circular symmetry of the photon orbit would violate the "no-hair" theorem of GR. However, these observations have heretofore not been possible due to the very small angular size of the shadow as seen from Earth. The Event Horizon Telescope (EHT) is an array of millimeter-wavelength telescopes operating as a very long baseline interferometer (VLBI) array to observe nearby supermassive black holes at extremely high angular resolution. The EHT will be able to resolve the shadow of the Galactic Center black hole Sgr A*. We explore through simulations the traction that data from the EHT will have in extracting the size of the shadow in Sgr A*, and in particular the ability of long sensitive baselines to the phased ALMA array to determine the asymmetry of the black hole shadow. Our investigations demonstrate that millimeter-wavelength VLBI observations can provide new probes of GR in the strong-field regime. This work is funded by grants from the National Science Foundation. 229.08 Measuring the Spin of the Galactic Center Black Hole Jeremy Steeger1, J. C. Dolence2, S. S. Doeleman3, V. L. Fish3, C. F. Gammie2, S. C. Noble4, H. Shiokawa2, A. E. E. Rogers3 1MIT, 2University of Illinois, 3MIT Haystack Observatory, 4Rochester Institute of Technology. 8:00 AM - 7:00 PM Essex Ballroom The Event Horizon Telescope (EHT) is an array of millimeter-wavelength telescopes that participate in very long baseline interferometry (VLBI) observations of supermassive black holes at extremely high angular resolution. For the Galactic Center black hole Sgr A*, the resolution of the EHT is a few Schwarzschild radii, sufficient to probe the inner accretion flow. Since the orbital period of material at the innermost stable circular orbit (ISCO) is a strong function of the spin of the black hole, measuring periodicity in the accretion flow provides a lower limit on the black hole spin. Recent general relativistic magnetohydrodynamic models (GRMHD) of the accretion flow are capable of qualitatively reproducing the variability in flux density seen at millimeter wavelengths. These models exhibit significant variability on scales near the ISCO. We examine prospects for detection of (quasi-)periodicity in the millimeter VLBI signatures of GRMHD models given expected performance parameters of the EHT. These simulations inform the feasibility of measuring the spin of the black hole in Sgr A* assuming a realistic model of the accretion flow around the black hole. This work is funded by grants from the National Science Foundation. 229.09 Status of the Event Horizon Telescope Vincent L. Fish1, S. S. Doeleman1, Event Horizon Telescope collaboration 1MIT Haystack Observatory. 8:00 AM - 7:00 PM Essex Ballroom The goal of the Event Horizon Telescope (EHT) project is to understand the physical and astrophysical processes of supermassive black holes though extremely high angular resolution observations. The EHT consists of existing millimeter-wavelength telescopes that participate in very long baseline interferometry (VLBI) observations of Sagittarius A*, M87, and active galactic nuclei. For the nearest sources, the EHT is uniquely capable of providing a resolution of a few Schwarzschild radii. Prior EHT observations have demonstrated very compact structure in Sgr A* and have been used to constrain the orientation of the black hole spin vector, strengthen the case for the existence of an event horizon, and examine the spatial characteristics of the variable millimeter emission. The sensitivity and angular resolution of the array are increasing due to the inclusion of new telescopes and several technical developments currently underway. We will summarize the most recent observations as well as the outlook for further enhancements of the capabilities of the EHT in the near future. This work is funded by grants from the National Science Foundation. 230 Binary Stellar Systems, X-ray Binaries Poster Session America Ballroom Foyer 230.01 Photometric and Spectroscopic Observations of Solar Type Eclipsing Binary, GSC 0620 1143 Ronald G. Samec1, P. M. Smith1, R. Robb2, D. R. Faulker3, W. van Hamme4 1Bob Jones Univ., 2University of Victoria, Canada, 3University of South Carolina, Lancaster, 4Florida International University. 8:00 AM - 7:00 PM America Ballroom Foyer We present a spectra, UBVRcIc photometric observations and a solution for the high amplitude, solar type eclipsing binary, GSC 0620 1143. A period study and a light curve solution are also presented. Our observations were taken with the 0.81-m Lowell Reflector on 19, 20 and 21 September 2008 with time granted through the National Undergraduate Observatory (NURO). The high precision light curves were premodeled with Binary 3.0, and then solved with the 2004 version Wilson code. Our modeled light curves included 205 U and B, 207 V, 202 R and 203 I individual CCD observations taken with the 2K X 2K NASACAM. Spectra taken at DAO on 23 November 2008 revealed that the variable star has a spectral type of G6±1 V. Four mean times of minimum light were determined, including HJDMin I = 2454731.6902(±0.0007)d, and HJDMin II =2454729.9049(±0.0004)d, 2454730.8790(±0.0002)d and 2454731.8532(±0.0002)d. Two more timings were found or determined from published data to determine the following light elements: J.D. Hel Min I = 2454731.6906(±0.0021)d + 0.32469886(±0.00000044) • E. Our Wilson Code analysis of GSC 0620 1143 revealed it to be a W-type contact binary (the less massive component, the hotter) with a mass ratio of 2.3. The system parameters from our model included a shallow fill-out of 0.08, a slight temperature difference of 205 K and an inclination of 80 degrees. Two minor hot spot regions (15 and 7 degree radii and 1.39, 1.18 TFACT values on the primary and secondary stars, respectively) were needed. We wish to thank the American Astronomical Society small research grant program and the Arizona Space Grant for supporting this research. 230.02 Searching For Low-mass Companions Of Cepheids Nancy Remage Evans1, H. Bond2, G. Schaefer3, M. Karovska1, B. Mason4, J. DePasquale1, I. Pillitteri1, E. Guinan5, S. Engle5 1SAO, 2Space Telescope Science Institute, 3Georgia State Univ., CHARA Array, 4US Naval Observatory, 5Villanova Univ.. 8:00 AM - 7:00 PM America Ballroom Foyer The role played by binary and multiple stars in star formation is receiving a great deal of attention, both theoretically and observationally. Two questions under discussion are how wide physical companions can be and how frequently massive stars have low mass companions. An important new observational tool is the development of high resolution imaging, both from space and from the ground (Adaptive Optics and interferometry). We are conducting a snapshot survey of the nearest Cepheids using the Hubble Space Telescope Wide Field Camera 3 (WFC3). The aim is to discover possible resolved low mass companions. Results from this survey will be discussed, including images of Eta Aql. X-ray luminosity can confirm or refute that putative low mass companions are young enough to be physical companions. This project tests the reality of both wide and low mass companions of these intermediate-mass stars. 230.03 Long Period Eclipsing Binaries in the Magellanic Clouds: a Period-I Magnitude Relation Edward J. Devinney1, A. Prsa1, E. F. Guinan1 1Villanova University. 8:00 AM - 7:00 PM America Ballroom Foyer The Eclipsing Binaries via Artificial Intelligence (EBAI) project (Prsa et al) generated solutions for eclipsing binaries in the Large Magellanic Cloud (LMC) as observed by the OGLE II project. Automatic clustering applied to the results highlighted that the LMC’s long period (P>10d) detached (EA) binaries follow a linear relation in Period-I magnitude (Devinney et al). Subsequent analysis of OGLE II data for the Small Magellanic Cloud (SMC) has revealed a similar relationship. The present relation is distinct from the Period-K band linear relation for LMC MACHO Project (Alcock et al) EBs as found by Wood et al, and discussed by Soszynski et al and Derekas et al. The Period-K band relation is convincingly modeled by invoking one EB component at the Roche lobe, whereas EBs in the Period-I magnitude relation reported here show minimal proximity effects and they are significantly fainter. We show that the Period-I magnitude relation is not a selection effect and weigh alternatives for its evolutionary basis. We are grateful for the support of this research from NSF/RUI Grant AST-05-75042. 230.04 Regular High Resolution Full Visual Spectrum Monitoring of Epsilon Aurigae Throughout Its 2009-2011 Eclipse John C. Martin1, J. O'Brien1 1U of Illinois Springfield. 8:00 AM - 7:00 PM America Ballroom Foyer Over the past two years the star Epsilon Aurigae has dimmed as a companion with a thick dusty disk eclipses it. Throughout this event we have taken regular biweekly high resolution Echelle spectroscopy to record changes in the absorption profiles. Measurements of the features introduced into the stellar spectrum by the intervening disk map its structure and physical parameters. While others have focused their high-resolution spectroscopy efforts on narrow ranges of wavelength targeting specific well-studied absorption features, our data covers from 970 nm - 315 nm allowing us to discover additional features in the spectrum that vary during the eclipse. 230.05 Towards A Full Orbital Solution For Epsilon Aurigae Brian K. Kloppenborg1, P. Hemenway1, E. Jensen2, W. Osborn3, R. Stencel1 1University of Denver, 2Swarthmore College, 3Central Michigan University. 8:00 AM - 7:00 PM America Ballroom Foyer Epsilon Aurigae is an eclipsing binary with a 27-year period that has baffled investigators for almost two centuries. The data from present and prior eclipses have strengthened our understanding of the system, but a comprehensive understanding of it's evolutionary state has remained illusive. There are presently two competing views: (1)the F-star primary is a supergiant of ~15 Mo with a companion that is equally massive, yet obviously much smaller, that has yet to evolve off the MS or (2)the F-star is a post-AGB object of ~4 Mo with a MS companion of ~6-7 Mo that is enshrouded in an accretion disk of debris from the F-star. Deciding between the two models depends on having an accurate distance to the system. Published parallaxes all agree within their formal uncertainties, but have error bars larger than the nominal value. We have found that all astrometric results either neglected orbital motion or relied on orbital elements that are not congruent with spectroscopy (Stefanik et al. 2010) and with the recent in-eclipse interferometric observations (Kloppenborg et al. 2010). For example, all astrometric orbital solutions (van de Kamp 1978, Strand 1959, Heintz and Cantor 1994) assumed an eccentricity that does not agree with present value, e = 0.22-0.26 (Stefanik et al. 2010, Chadima et al. 2010), rather than solving for it. Likewise the HIPPARCOS parallax used Heintz's orbit that we argue is incorrect. We are deriving new orbital solutions for both components in the system. The solution for the F-star will use radial velocity and astrometric observations. The solution for the eclipsing object comes from the relative motion of the components implied by interferometric imaging. The University of Denver participants are grateful for support under NSF grant 10-16678 and the bequest of William Hershel Womble in support of astronomy at the University of Denver. 230.07 Fundamental Parameters of 4 Massive Eclipsing Binaries in Westerlund 1 Alceste Z. Bonanos1, E. Koumpia1 1IAA, National Observatory of Athens, Greece. 8:00 AM - 7:00 PM America Ballroom Foyer We present fundamental parameters of 4 massive eclipsing binaries in the young massive cluster Westerlund 1. The goal is to measure accurate masses and radii of their component stars, which provide much needed constraints for evolutionary models of massive stars. Accurate parameters can further be used to determine a dynamical lower limit for the magnetar progenitor and to obtain an independent distance to the cluster. Our results confirm and extend the evidence for a high mass for the progenitor of the magnetar. The authors acknowledge research and travel support from the European Commission Framework Program Seven under the Marie Curie International Reintegration Grant PIRG04-GA-2008-239335. 230.08 Do Neutron stars Or Black Holes Dominate The X-ray Binary Population Of The Youngest Starburst Galaxies? Silas Laycock1, A. Camero2, C. Wilson-Hodge2, B. Williams3, M. Garcia4, A. Prestwich4 1UMass Lowell, 2MSFC, 3U. Washington, 4CfA. 8:00 AM - 7:00 PM America Ballroom Foyer We report on our year-long (2009-'10) campaign with the Chandra X-ray observatory, to capture the transient X-ray binary (XRB) population in the nearby starburst galaxy IC10 in Cassiopeia. Together with archival data, the study includes 225 ksec of Chandra exposure for a limiting luminosity depth of logLX>35; sensitive to high-mass XRBs containing neutron stars, black holes, and to X-ray novae. Our study aims to characterize the XRB population in the youngest available starburst, which should be dominated by the most massive stars and their newly formed relics. Of ~100 X-ray sources; 20% are strong variables, and 40% are associated with massive stars. Contemporaneous optical spectroscopy from Gemini observatory is providing spectral types and hence the masses, ages and composition of these extragalactic XRBs. 230.09 Discovery And Multi-wavelength Observations Of The New X-ray Transient Source Swift J1357.2-0933 Hans A. Krimm1, J. Bloom2, N. Gehrels3, S. T. Holland1, J. A. Kennea4, C. B. Markwardt3, J. Miller-Jones5, G. Sivakoff6 1CRESST/USRA/NASA's GSFC, 2University of California, Berkeley, 3NASA's GSFC, 4Pennsylvania State University, 5Curtin University, Australia, 6University of Virginia. 8:00 AM - 7:00 PM America Ballroom Foyer We report on the discovery by the Swift Gamma-Ray Burst Explorer of the transient source Swift J1357.2-0933 and the subsequent course of an outburst beginning in January 2011. The source is most likely a low-mass X-ray binary, although it is not yet clear whether the compact object is a black hole or neutron star. The object is off the galactic plane (galactic latitude = +50.003 degrees), so it is likely nearby (1-10 kpc), since an extra-galactic origin is ruled out by the large (~6 magnitude) amplitude of the outburst in the optical. This interpretation means that the measured X-ray and radio flux are both underluminous compared to typical black hole X-ray binaries. In the power spectrum there are no clear pulsations, while there is evidence of a low frequency quasi-periodic oscillation. The source was observed for more than a month with multiple instruments and we report on observations with the Swift Burst Alert Telescope, X-Ray Telescope and Ultraviolet/Visible Telescope, the RXTE Proportional Counter Array, the PAIRITEL near-infrared telescope and the EVLA at 4.6 and 7.9 GHz. The rise in hard X rays from an undetectable level lasted about 2 days. The initial optical light curve shows a very slow decay (~0.3 magnitudes over 24 days) in all bands, while in X rays, the rate is steady for the first six days, followed by a more rapid decline with a flat hardness ratio (0.3-1.5 kev/1.5-10.0 keV). The spectrum during this period is well-fitted by a simple absorbed power law with photon index ~1.6 with no need for a thermal component. We report on the multi-wavelength observations of Swift J1357.2-0933 and discuss the evidence in support and opposition to various models for the nature of this new nearby X-ray source. 230.10 Identification of Supersoft X-ray Sources and Quasisoft X-ray Sources in the Magellanic Clouds Using XMM-Newton Tsz Ho Tsang1, K. L. Li1, C. S. J. Pun1, R. Di Stefano2, A. K. H. Kong3 1The University of Hong Kong, Hong Kong, 2Havard-Smithsonian Center for Astrophysics, 3National Tsing Hua University, Taiwan. 8:00 AM - 7:00 PM America Ballroom Foyer Supersoft X-ray Sources (SSSs) and Quasisoft X-ray Sources (QSSs), collectively known as Very Soft Sources (VSSs), are observationally defined as X-ray sources having no or little emission above 1 keV together with energy spectra exhibiting characteristic temperature of tens of eV and roughly between 175 to 350 keV respectively. A systematic search in the Magellanic Clouds (MCs) was done using public archival data of the XMM-Newton observatory spanning from year 2000 to 2009. The VSSs candidates were identified using an automated source selection program based on hardness ratio criteria defined by count rates in three different energy bands (0.1-1.1 keV, 1.1-2.0 keV, 2.0-7.0 keV). Potential sources were checked for optical (USNO-B1.0) and infrared (2MASS) counterparts using automatic catalogue-querying scripts in order to verify their identity and to screen out foreground stars. The algorithm is effective in recovering previously identified VSSs in the MCs. Moreover, it enables us to investigate long-term X-Ray variability of these sources by comparing multiple data sets and serves as a tool for discovering new VSS candidates in other sky regions. This project is supported by the General Research Fund HKU704709P of the Hong Kong SAR government. 230.11 On the Nature of the Microquasar GRS 1915+105: Clues from Radio Polarization Imaging. John F. C. Wardle1, E. A. Dare2, C. C. Cheung3 1Brandeis Univ., 2Tufts Univ., 3Naval Research Laboratory. 8:00 AM - 7:00 PM America Ballroom Foyer We present a sequence of images of the polarized radio emission from the Galactic superluminal source GRS 1915+105 made from archival VLA data taken in 1994. Between February and April there are 10 observations made in the A array, mostly at 8 GHz, and four outbursts can be seen. The images reveal a wealth of information which cannot be obtained from the total intensity images. The second and third outbursts are well observed in polarization and they exhibit very different behaviors. In the second outburst the magnetic field direction is aligned along the jets throughout the burst. We show that the evolution of the total intensity and fractional polarization can be fit with a simple shock-in-jet model. The third outburst (in which Mirabel and Rodriguez discovered superluminal motion) behaves quite differently. It is a much more powerful outburst and it decays more slowly than the second outburst. Its polarization behavior is complex. The polarization electric vector position angles in both jets rotate rapidly, but in opposite directions and at different rates. The fractional polarization also changes in a complex way indicating internal polarization structure. In the last three epochs the VLA resolves this polarization structure in the south-east (approaching) jet, which is seen at later times in its evolution than the north-west (receding) jet, due to light travel time effects. The third outburst evolves too rapidly and in too complex a manner to fit a detailed model, but a qualitative description in terms of the shock-in-jet model can be given. This work was supported by the NSF. 230.12 A Coincident Search for Radio and Gravitational Waves from Binary Neutron Star Mergers Brett Cardena1 1The College of New Jersey. 8:00 AM - 7:00 PM America Ballroom Foyer The merger of neutron star-neutron star binary pairs may be accompanied by the prompt emission of a coherent low-frequency radio pulse. This radio transient is produced as synchrotron radiation caused by the spin and rotation of the surface charge density of a pulsar through the magnetosphere of a larger neutron star, usually referred to as a Magnetar . This type of merger event would also result in the release of a gravitational coalescence wave-form. We will discuss a coincident radio transient and gravitational wave search. This search is being conducted by two radio telescope arrays: The Long Wave Array (LWA) and the Eight-meter-wavelength Transient Array (ETA) in coordination with the Laser Interferometer Gravitational-Wave Observatory (LIGO). We will outline this ongoing coincident search and discuss some preliminary results. 230.13 The Stability of Hoyle-Lyttleton Accretion in Three Dimensions John M. Blondin1, E. Raymer1 1North Carolina State Univ.. 8:00 AM - 7:00 PM America Ballroom Foyer The gravitational accretion of gas onto a compact star moving supersonically through a uniform ambient medium is dynamically unstable in the restricted case of two-dimensional planar geometry (a cylindrical star). Numerical simulations in 3D (e.g., the series of papers by Ruffert) show some hint of instability, but not the dramatic flip-flop seen in 2D planar simulations. We extend the recent 2D numerical simulations of Blondin and Pope (2009) to 3D using the overset spherical grid approach developed by Kageyama and Sato (2004). Using this grid geometry on current supercomputers allows us to simulate the smallest accretors studied in previous 3D work, but with an order of magnitude higher spatial resolution. For an ideal gas with a ratio of specific heats of 5/3, we find relatively minor time variability in the subsonic flow between the head of the accretion bow shock and the accreting star. Overall the bow shock and mass accretion rate remain nearly constant in time, with negligible angular momentum accreted onto the compact star. 231 The Milky Way, the Galactic Center Poster Session America Ballroom Foyer 231.01 Using Open Clusters to Constrain the Large Scale Structure of the Galactic Magnetic Field and the Distribution of Polarizing Dust April Pinnick1, D. P. Clemens1, M. Pavel1 1Boston University. 8:00 AM - 7:00 PM America Ballroom Foyer We present near-infrared H-band (1.6 microns) imaging polarimetry of open clusters taken with Mimir on the Perkins telescope outside Flagstaff, AZ. Over half of the 30+ clusters are located within the GPIPS region, an H-band background starlight polarization survey spanning L = 18 to 56 degrees and B = -1 to +1 degrees, and the remaining clusters are located in the outer Galaxy, from L = 119 to 215 degrees and B = -5 to +32 degrees. Membership within a cluster is assessed from a variety of methods, and is largely dependent on available data in the literature. The trends with longitude in degree of polarization and angle of polarization of the NIR polarimetry are compared to available optical polarimetry trends. These show both correspondences and deviations from each other. The large scale structure of the Galactic magnetic field, as well as the large scale distribution of polarizing dust, is discussed. This work partially supported by NSF grants AST 06-07500 and 09-07790. 231.02 Formation And Evolution Of The Disk System Of The Milky Way: [α/Fe] Ratios And Kinematics Of The SEGUE G-dwarf Sample Timothy C. Beers1, Y. Lee1, D. An2, R. Schoenrich3, C. M. Rockosi4, H. L. Morrison5, J. A. Johnson6, A. Just7, Z. Ivezic8, J. Bird6, B. Yanny9, P. Harding5 1Michigan State Univ./JINA, 2Ewha Womans Univ., Korea, Republic of, 3MPIA, Germany, 4Lick Observatory/UCSC, 5Case Western Reserve Univ., 6Ohio State University, 7Univ. of Heidelberg, Germany, 8Univ. of Washington, 9FNAL. 8:00 AM - 7:00 PM America Ballroom Foyer We present the derived local kinematics for a sample of some 17,500 G-type dwarfs in the solar neighborhood, and compare with the rotational velocity gradients on metallicity, the radial and vertical velocity gradients, and the stellar orbital eccentricity distributions predicted by contemporary models for the formation and evolution of the Milky Way's disk system. The sample is culled from an original total of some 63,000 G dwarf candidates having available low-resolution (R = 2000) spectra, ugriz photometry, proper motions, and the latest stellar atmospheric parameter estimates (Teff, log g, [Fe/H]) from the eighth public release of the Sloan Digital Sky Survey. Using estimates for [α/Fe] as a reference, we divide our local dwarf sample within |Z| < 3 kpc from the Galactic plane and 7 < R < 10 kpc into likely thin-disk and thick-disk components. The thin-disk subsample exhibits a strong gradient in observed rotational velocity with [Fe/H] (-22 km/s/dex), which contrasts with expectations from classical local chemical evolution models. The thick-disk subsample exhibits a small slope in rotational velocity with distance from the Galactic center (-5.6 km/s/kpc), in line with expectations from gas-rich merger models. The observed distribution of orbital eccentricities for our thick-disk subsample is also in better agreement with gas-rich merger models for the origin of the thick disk, rather than arising (solely) due to radial migration or pure accretion. Based on these results we propose that, while radial migration appears to have played an important role in the evolution of the thin-disk population, it may be less important than gas-rich mergers or thin-disk heating in the formation of the thick disk. 231.03 Recognition of Distant Supergiants among Faint Red Stars in the Galactic Plane Darrell J. MacConnell1, R. F. Wing2, E. Costa3 1Computer Sciences Corp., 2Ohio State University, 3Universidad de Chile, Chile. 8:00 AM - 7:00 PM America Ballroom Foyer Surveys along the Galactic plane at red and infrared wavelengths -- e.g. several objective-prism surveys in the photographic infrared, and the recent Spitzer/GLIMPSE survey in the 3-8μ region -- record large numbers of faint red stars. Some of these sources must be distant, heavily-reddened supergiants in remote spiral arms, and they would be valuable tracers if their distances could be estimated. Measurement of a TiO band and a color index -- show that the majority of the detected faint, red sources are stars of type M, reddened to different degrees. It is more difficult to distinguish bona fide supergiants from the more common giants (which are also likely to be reddened, but are not confined to spiral arms), and to obtain the luminosity classes needed for the determination of individual distances. We have developed two methods, one using slit spectroscopy and the other narrow-band photometry, for determining the luminosities of reddened M stars. Both methods depend primarily on the measurement of CN absorption in the 0.8μ region, often in the face of much stronger TiO bands. The spectroscopic method involves flattening the digital spectra and comparing program stars to standards 0f the same TiO strength to judge the amount of CN present. The narrow-band method involves fitting a blackbody curve to the calibrated photometry and defining a reddening-free CN index. This CN absorption is measurable in all giants and supergiants of types K and M and is stronger in supergiants. In fact, young, massive supergiants of classes Ia and Iab, which should be excellent spiral-arm tracers, can be distinguished from supergiants of class Ib, which may be older. We illustrate our procedures and apply them to a sample of GLIMPSE sources. We show that our methods give consistent results and can be used to identify distant supergiants among GLIMPSE sources. 231.04 Ionized Gas Kinematics in the Inner 2 pc of the Milky Way: A Spiral Wave in a Keplerian Disk John H. Lacy1, W. Irons1 1Univ. of Texas. 8:00 AM - 7:00 PM America Ballroom Foyer Numerous studies have been made of the ionized gas distribution and kinematics in Sgr A West, at the center of the Milky Way. Most of these have modeled the arcs of ionic emission as tidally stretched streamers, with the gas flowing along the streamers. A different model was proposed by Lacy et al. (1991), who argued that the observations required nearly circular motions for much of the gas, rather than motions along the streamers. Several physical explanation were suggested for how such a wave pattern could occur. None of the explanations were very compelling. We present new observations of the [Ne II] (12.8um) emission from Sgr A West, with improved spectral and spatial resolution (4 km/s and 1 arcsec). We compare the observations with models assuming the gas moves along elliptical orbits and models in which it moves across the streamers on circular orbits. The data strongly favor the latter model for much of the ionized gas. We still have no satisfactory physical explanation for how the gas is organized or ionized along what appears to be spiral wave. This work was supported by NSF grant AST-0607312. 232 Pulsars, Neutron Stars and Related Topics Poster Session America Ballroom Foyer 232.01 A Large-Bandwidth High Frequency Survey for Radio Pulsars in the Galactic Center Robert Wharton1, W. Majid2, J. Deneva1 1Cornell University, 2JPL. 8:00 AM - 7:00 PM America Ballroom Foyer We are currently undertaking a deep search for radio pulsars in the Galactic Center (GC) using the DSS28 telescope at the Goldstone Deep Space Communications Complex. The detection of a pulsar in the inner parsecs of the GC would provide an excellent probe of the GC environment and the central supermassive black hole. Despite the detection of over 1800 pulsars in the Galaxy so far, none have been found within 10' of the GC. This is mainly due to the large pulse broadening times (~6ν-4 seconds for a pulsar in the GC) caused by the scattering of radio waves. The 34 meter DSS28 dish has been outfitted with a wide bandwidth receiver capable of providing 8 GHz of instantaneous bandwidth distributed within a frequency range of 2-14 GHz. The high observing frequencies will help mitigate the pulse broadening due to scattering and the high bandwidth will prove useful in single pulse searches. Overall, the DSS28 telescope provides a unique opportunity for a multi-month directed search for radio pulsars in the GC at high frequencies. 232.02 Chandra observations of PSR B1451-68 Bettina Posselt1, G. G. Pavlov1, G. P. Garmire1 1Pennsylvania State University. 8:00 AM - 7:00 PM America Ballroom Foyer Very few old radio pulsars are detected in X-rays. These objects are in general very faint due to their cold surfaces and relatively low spin-down powers. Yet, old radio pulsars appear to convert their spin-down energy more efficiently into X-ray emission than their younger relatives. It is unclear how much of this X-ray emission can be attributed to thermally emitting, hot polar caps or to magnetospheric emission. The evolution of NS magnetospheres with age and the polar cap heating mechanism are both interesting for the entire NS population, but can be particularly well studied in the case of old X-ray detected radio pulsars. Here, we present recent Chandra observations of the 4.25e7 yrs old radio pulsar PSR B1451-68. The spectrum of the found X-ray source can be described by a power law with photon index ∼ 2.7. Its isotropic luminosity is L_X ∼ 1.7e30 d^2_450pc erg/s (0.3 keV to 8keV), which corresponds to a high X-ray efficiency of 8e-3. We discuss the influence of a nearby star on the detected X-ray emission. 233 Cosmology Poster Session America Ballroom Foyer 233.01 PIPER: Primordial Inflation Polarization Explorer Justin Lazear1, D. Benford2, D. Chuss2, D. Fixsen2, J. Hinderks2, G. Hinshaw3, C. Jhabvala2, B. Johnson2, A. Kogut2, P. Mirel2, H. Mosely2, J. Staghun2, E. Wollack2, A. Weston2, K. Vlahacos2, C. Bennett1, J. Eimer1, M. Halpern3, K. Irwin4, J. Dotson2, P. Ade5, C. Tucker5 1Johns Hopkins University, 2NASA-GSFC, 3University of British Columbia, Canada, 4NIST, 5Cardiff University, United Kingdom. 8:00 AM - 7:00 PM America Ballroom Foyer The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne instrument to measure the polarization of the cosmic microwave background in search of the expected signature of primordial gravity waves excited during an inflationary epoch shortly after the Big Bang. PIPER consists of two co-aligned telescopes, one sensitive to the Q Stokes parameter and the other to U. Sky signals will be detected with 5120 transition edge sensor (TES) bolometers distributed in four rectangular close-packed arrays maintained at 100 mK. To maximize the sensitivity of the instrument, both telescopes are mounted within a single open bucket dewar and are maintained at 1.5 K throughout flight, with no ambient-temperature windows between the sky and the detectors. To mitigate the effects of systematic errors, the polarized sky signals will be modulated using a variable-delay polarization modulator. PIPER will observe at frequencies 200, 270, 350, and 600 GHz to separate the CMB from polarized dust emission within the Galaxy. A series of flights alternating between northern and southern hemisphere launch sites will produce nearly full-sky maps in Stokes I, Q, U, and V. I will discuss the current status and potential science returns from the PIPER project. 233.02 New Results from the Atacama Cosmology Telescope David N. Spergel1 1Princeton Univ. Obs.. 8:00 AM - 7:00 PM America Ballroom Foyer The Atacama Cosmology Telescope has surveyed several hundred square degrees of sky with arcminute resolution at 145 and 220 GHz. I will highlight some of the recent measurements from ACT: a precise measurement of the acoustic peaks, a large cluster sample, cross-correlations with multiwavelength tracers and measurements of the gravitational lensing of the cosmic microwave background. 233.03 Probing the First Stars and Black Holes with the Dark Ages Radio Explorer (DARE) Jack O. Burns1, J. Lazio2, J. Bowman3, R. Bradley4, C. Carilli4, S. Furlanetto5, G. Harker1, A. Loeb6, J. Pritchard7 1Univ. of Colorado at Boulder, 2JPL, 3Arizona State University, 4National Radio Astronomy Observatory, 5UCLA, 6Harvard University, 7Harvard-Smithsonian Center for Astrophysics. 8:00 AM - 7:00 PM America Ballroom Foyer The Dark Ages Radio Explorer (DARE) will use the highly-redshifted hyperfine 21-cm transition from neutral hydrogen to track the formation of the first stars, black holes, and galaxies by their impact on the intergalactic medium during the end of the Dark Ages and during Cosmic Dawn (z = 11-35). DARE will measure the sky-averaged spin temperature of neutral hydrogen at the unexplored epoch 80-420 million years after the Big Bang, providing the first evidence of the earliest objects to illuminate the cosmos and testing our models of galaxy formation. DARE’s science objectives include (1) When did the first stars form? (2) When did the first accreting black holes form? (3) When did Reionization begin? (4) What surprises does the end of the Dark Ages hold (e.g., Dark Matter decay)? DARE will answer two fundamental questions identified in the recent Astro2010 Decadal Survey, New Worlds, New Horizons in Astronomy and Astrophysics: What were the first objects to light up the Universe, and when did they do it? The birth of the first stars and black holes is one of the truly transformative events in the history of the Universe. DARE’s approach is to measure the spectral shape of the sky-averaged redshifted 21-cm signal over the redshift range 11-35, corresponding to radio frequencies 40-120 MHz. DARE orbits the Moon for a baseline mission of 3 years and takes data above the lunar farside, the only location in the inner solar system proven to be free of RFI. The smooth frequency response and differential radiometry of DARE are effective in removing the remaining foregrounds (i.e., the Galaxy and solar system objects). 233.04 The Log-Density as a Better Cosmological Density Variable Mark C. Neyrinck1, X. Wang1, B. Falck1, I. Szapudi2, A. Szalay1 1Johns Hopkins Univ., 2IfA. 8:00 AM - 7:00 PM America Ballroom Foyer We discuss a few ways in which the log-density A is superior to the conventional overdensity in characterizing the large-scale structure of the Universe. A has a power spectrum with much smaller nonlinearities in both its shape and covariance. Thus it gives tighter constraints on many cosmological parameters. A is also more useful in estimating the displacement field in Lagrangian reconstruction methods. 234 Dark Matter & Dark Energy/Large Scale Structures, Cosmic Distance Scale Poster Session America Ballroom Foyer 234.01 Satellite Galaxies as Probes of Dark Matter Halos Ingolfur Agustsson1, T. G. Brainerd1 1Boston University. 8:00 AM - 7:00 PM America Ballroom Foyer We use a LCDM simulation to study the locations and motions of satellite galaxies relative to their host galaxies. We concentrate on relatively isolated hosts, selected for being the brightest galaxies in their region of space, and we use the smaller, fainter satellites found around the hosts to probe the hosts' dark matter halos. A single observed host galaxy has too few satellites for those satellites to provide, on their own, a reliable probe of the dark matter halo of that particular host. However, a large number of hosts can be collected from a redshift survey such as the SDSS, which makes it possible to compute host-satellite ensemble averages. This allows us to measure the mean velocity field around the hosts and to study the shape of the velocity distribution in order to infer the corresponding velocity dispersion. Here we evaluate the biases that occur when it is assumed that the satellites are fair tracers of the dark matter halos of the host galaxies. In particular, our study highlights the fact that, in order to use satellite galaxies as accurate probes of the halos around the host galaxies, the hosts need to be in a reasonably relaxed state and the satellites need to have reached some level of equilibrium with the halo they are to measure. Utilizing simulations in this way is extremely useful in suggesting models and hypotheses for further exploration in observations. This knowledge is necessary to be able to interpret observations of hosts and satellites, and to then infer the properties of the underlying dark matter structure. This work was supported in part by the National Science Foundation. 234.02 Self-Similar Secondary Infall: Trying to Understand Halo Formation Phillip Zukin1, E. Bertschinger1 1MIT. 8:00 AM - 7:00 PM America Ballroom Foyer N-body simulations have revealed a wealth of information about dark matter halos, but their results are largely empirical. Using analytic means, we attempt to shed light on simulation results by generalizing the self-similar secondary infall model to include tidal torque. Imposing self-similarity allows us to analytically calculate the structure of the the halo in different radial regimes and numerically compute the profiles of the halo without being limited by resolution effects inherent to N-body codes. I will describe this simplified halo formation model and compare our results to mass and velocity profiles from recent N-body simulations. We find that angular momentum plays an important role in determining the structure of the halo at small radii. 234.03 Baryon Acoustic Oscillations Analysis Techniques Xiaoying Xu1, J. Eckel1, D. Eisenstein2, M. Metchnik1, N. Padmanabhan3, P. Pinto1, H. Seo4, M. White4 1University of Arizona, 2Harvard CfA, 3Yale, 4UC Berkeley, LBNL. 8:00 AM - 7:00 PM America Ballroom Foyer We present a new statistic ωl(rs) for analyzing the Baryon Acoustic Oscillations (BAO) which involves a weighted integral over the power spectrum or correlation function. This effectively filters P(k) or ξ(r) to extract the embedded acoustic information. The form of the weighting function lends nice properties to ωl giving it key advantages over the other statistics. We also present techniques for analyzing mock catalogues including a method for deriving a covariance matrix using the mock data. We illustrate this process using SDSS DR7 mocks produced from the LasDamas simulations and use the resulting covariance matrix to demonstrate the robustness of a basic fitting form for measuring the BAO scale. 234.04 Galaxy Bias and its Effects on the Baryon Acoustic Oscillations Measurements Kushal Mehta1, H. Seo2, J. Eckel1, D. Eisenstein3, M. Metchnik1, P. Pinto1, X. Xu1 1University of Arizona, 2Berkeley Center for Cosmological Physics, LBL and Department of Physics, University of California, Berkeley, 3Harvard University. 8:00 AM - 7:00 PM America Ballroom Foyer The baryon acoustic oscillation (BAO) feature in the clustering of matter in the universe serves as a robust standard ruler and hence can be used to map the expansion history of the universe. We use high force resolution simulations to analyze the effects of galaxy bias on the measurements of the BAO signal. We apply a variety of Halo Occupation Distributions (HODs) and produce biased mass tracers to mimic different galaxy populations. We investigate whether galaxy bias changes the non-linear shifts on the acoustic scale relative to the underlying dark matter distribution presented by Seo et al (2010). For the less biased HOD models (b < 3), we do not detect any shift in the acoustic scale relative to the no-bias case, typically 0.10% ± 0.10%. However, the most biased HOD models (b > 3) show a shift at moderate significance (0.79% ± 0.31% for the most extreme case). We test the one-step reconstruction technique introduced by Eisenstein et al. (2007) in the case of realistic galaxy bias and shot noise. The reconstruction scheme increases the correlation between the initial and final (z = 1) density fields achieving an equivalent level of correlation at nearly twice the wavenumber after reconstruction. Reconstruction reduces the shifts and errors on the shifts. We find that after reconstruction the shifts from the galaxy cases and the dark matter case are consistent with each other and with no shift. The 1σ systematic errors on the distance measurements inferred from our BAO measurements with various HODs after reconstruction are about 0.07% - 0.15%. 234.05 Nonlinear Behavior of Baryon Acoustic Oscillations from the Zeldovich Approximation Using a Non-Fourier Perturbation Approach Nuala McCullagh1, A. S. Szalay1 1Johns Hopkins University. 8:00 AM - 7:00 PM America Ballroom Foyer Baryon acoustic oscillations have become the favored technique to constrain the properties of dark energy in the Universe. In order to accurately characterize the equation of state, we must understand the effects of both the non-linearities and redshift space distortions on the location and strength of the acoustic peak. Here, we consider these effects using the Zel’dovich approximation and a novel approach to 2nd order perturbation theory. Linear theory predicts that the correlation function, and its Fourier transform, the power spectrum, grow as the square of the growth factor, D(t). The next term in the expansion may have a non-negligible contribution at later times. In the Zel’dovich approximation, the second order term is built from convolutions of the power spectrum with polynomial kernels in Fourier space. This suggests that it may be possible to write the correlation function as a sum of second order products of a broader class of correlation functions, expressed through simple spherical Bessel transforms of the power spectrum. We show how to systematically perform such a computation. We explicitly prove that our result is the Fourier transform of the Fourier space result by Valageas (2010). Next we illustrate the benefit of writing the non-linear expansion in configuration space, as this calculation is more easily extended to redshift space than the Fourier space result. Finally, we compare our expressions to numerical simulations. 235 Relativistic Astrophysics, Gravitational Lenses & Waves Poster Session America Ballroom Foyer 235.01 Strong Gravitational Lensing Of mm And submm Surveys Yashar Hezaveh1, G. Holder1 1McGill University, Canada. 8:00 AM - 7:00 PM America Ballroom Foyer We have developed and used a ray-tracing simulation code to study the effects of strong gravitational lensing on the mm and submm galaxy surveys, in particular the new population of sources detected by South Pole Telescope (SPT) which are predicted to largely consist of strongly lensed galaxies at z>2. We compare our lensed number counts with the SPT observations and put constraints on some of the lens/source parameters. In addition we assess the effects of uncertainties in the lens/source models, such as the normalization of the velocity dispersion and finite source effects. We find that in spite of such uncertainties if lensing is taken into account the SPT observations are in good agreement with number count predictions. 235.02 A Preliminary Analysis of Cosmic Magnification of SDSS Galaxies Tereasa G. Brainerd1, T. V. Wenger1 1Boston Univ.. 8:00 AM - 7:00 PM America Ballroom Foyer Cosmic shear, the distortion of galaxy images by weak lensing, induces correlated ellipticities in the images of galaxies that are not physically close to one another. However, correlated galaxy images may also occur by mechanisms other than lensing (e.g., the galaxy formation process, or physical interactions after galaxy formation, may induce correlations in the images of galaxies that are close to one another). Such "intrinsic" alignments occur naturally in CDM and in shallow surveys (e.g., the SDSS) correlated ellipticities due to intrinsic alignments dominate over the correlated ellipticities due to cosmic shear. Because of the challenges of detecting and interpreting correlated galaxy images, the weak lensing community is now investigating cosmic magnification as a complement to cosmic shear. Cosmic magnification alters the clustering of galaxies. Lensing dilutes the local number density of galaxies because the area of a given patch of sky is increased. Also, since lensing conserves surface brightness, additional sources are added to the sample due to the fact that their images are magnified sufficiently that their lensed magnitudes fall within the magnitude limit of the data. The net effect is either a suppression or enhancement of the number density of galaxies, depending upon the logarithmic slope of the number counts. Here we present a preliminary measurement of cosmic magnification using SDSS galaxies. We compute the angular cross-correlation of foreground and background galaxies, using a combination of spectroscopic and photometric redshifts to define the foreground and background populations. The foreground and background are separated by a sufficient amount that they are not physically correlated. Therefore, any observed clustering of the foreground with the background is a sign of cosmic magnification. Lastly, we investigate the dependence of the lensing-induced cross-correlation on physical properties of the foreground galaxies. This work was supported in part by the National Science Foundation. 235.03 Finite Source Effects in Strong Lensing Austen Groener1 1Drexel University. 8:00 AM - 7:00 PM America Ballroom Foyer Gravitational lensing is one of the most stunning confirmations of Einstein's theory of general relativity. In the most extreme cases, distant objects like quasars can be lensed by the mass of intermediate galaxies to produce configurations of multiple images, sometimes as many as six. In particular, we focus on the “fold” lens configuration, where two of the images, mirror images of one another, lay very closely spaced across a critical curve. Since the entire galaxy’s mass distribution affects the magnification of the images, the flux ratio of the pair can be used as a tool for investigating substructure. In the absence of substructure, we would naively expect the two images to be of equal brightness. However, ‘anomalous’ (non-zero) flux ratios seem to dominate observations of such lens systems. Possible reasons that have been investigated include microlensing, differential absorption by dust, and galaxy substructure. However, we look at yet another possibility for ‘anomalous’ flux ratios, and one that will allow us to use the lensing galaxy as a microscope: the finite size of the background quasar. In the present work, we develop a semi-analytic expression for the magnification of images in a multiple-image lens system in which higher order lensing effects (and consequently higher order shape distortions) are taken into account. How the flux ratios will be affected by source size and image positions using this expression will need to be further assessed. In particular, we study where and when the flux ratio deviates from zero for fold lenses. This will ultimately allow us to model the radial color distribution in quasars, giving us new insights into their structure. 235.04 Stellar Tidal Disruption as an Electromagnetic Signature of Supermassive Black Hole Recoil Nicholas Stone1, A. Loeb1 1Harvard University. 8:00 AM - 7:00 PM America Ballroom Foyer A precise electromagnetic measurement of the sky coordinates and redshift of a coalescing black hole binary holds the key for using its gravitational wave signal to constrain cosmological parameters and to test general relativity. Here we show that the merger of ~106-7 Msun black holes is generically followed by electromagnetic flares from tidally disrupted stars. The sudden recoil imparted to the merged black hole by GW emission promptly fills its loss cone and results in a tidal disruption rate of stars as high as ~0.1 yr-1. The prompt disruption of a single star within a galaxy provides a unique electromagnetic flag of a recent black hole coalescence event, and sequential disruptions could be used on their own to calibrate the expected rate of GW sources for pulsar timing arrays or the proposed Laser Interferometer Space Antenna. We also examine the prospects for delayed detection of black hole recoil using upcoming time-domain surveys, by estimating event rates for spatially and kinematically offset tidal disruption flares. This work was funded by the Harvard University Astronomy Department, and by Professor Abraham Loeb’s NSF and NASA grants. 235.05 Gravitational Nanolensing from Subsolar Mass Dark Matter Halos Jacqueline Chen1, S. Koushiappas1 1Brown University. 8:00 AM - 7:00 PM America Ballroom Foyer We investigate the feasibility of extracting the gravitational nanolensing signal due to the presence of subsolar mass halos within galaxy-sized dark matter halos. We show that subsolar mass halos in a lensing galaxy can cause strong nanolensing events with shorter durations and smaller amplitudes than microlensing events caused by stars. We develop techniques that can be used in future surveys such as Pan-STARRS, LSST, and OMEGA to search for the nanolensing signal from subsolar mass halos. 236 Galaxy Clusters Poster Session America Ballroom Foyer 236.01 Specific Star Formation In Coma Cluster Galaxies Louise O. V. Edwards1, D. Fadda1 1California Institute of Technology. 8:00 AM - 7:00 PM America Ballroom Foyer We present the specific star formation rates for MIPS 24 micron selected Coma cluster galaxies. We build galaxy spectral energy distributions using archival optical and Mid-IR photometric data from Sloan and the Spitzer Space Telescope, as well as new near-IR data we have collected at Palomar. Spectra of ~100 Mid-IR selected members are collected and best fit model spectral energy distributions are found for each member galaxy to determine total infrared luminosities and galaxy masses. With the help of archival FIRST radio data, we quantify the amount of AGN contamination, and compare obscured starformation rates to unobscured rates derived from extinction-corrected Halpha line measurements. Finally, we examine the location of the strong starbursts in the cluster to better understand the galaxy activity in Coma. 236.02 Optical Substructure Analysis of Galaxy Clusters Identified by Double-lobed Radio Sources Joshua Wing1, E. Blanton1 1Boston University. 8:00 AM - 7:00 PM America Ballroom Foyer Using double-lobed radio sources from the Faint Images of the Radio Sky at Twenty Centimeters (FIRST) survey, and optical counterparts in the Sloan Digital Sky Survey (SDSS), we have identified a large number of galaxy clusters. These radio sources are driven by active galactic nuclei, and our cluster samples include objects with bent, double-lobed sources and straight, double-lobed sources. We also included a single-component comparison sample. We examine these galaxy clusters for evidence of optical substructure, testing the possibility that bent sources are formed in large-scale mergers. We use a suite of substructure analysis tools to determine the location and extent of substructure visible in the optical distribution of cluster galaxies, and compare the rates of substructure in clusters with different types of radio sources. Additionally we measure the position of the radio source in relation to the center of the cluster. 236.03 Star Formation in the Interacting Cluster System Abell 2197/2199 Seth A. Cohen1, G. A. Wegner1 1Dartmouth College. 8:00 AM - 7:00 PM America Ballroom Foyer We present preliminary analysis of the star formation (SF) distribution in the nearby (z ~ 0.03) interacting galaxy clusters Abell (hereafter A) 2197 and A2199 using data from the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7). The purpose of this work is to determine how the cluster distribution appears to affect SF. The SF distribution is compared with X-ray maps of the clusters. The diagnostic diagram, log([O III]λ5007 / Hβ) vs. log([N II]λ6583 / Hα), shows that most emission-line (EL) galaxies in both clusters are star-forming as opposed to Seyferts or LINERs. The distribution and equivalent widths of Hα in EL galaxies are plotted, as are surface brightness contours of both EL non-EL galaxies. While the EL and non-EL galaxies are similarly distributed in the smaller of the two clusters, A2197, we find bimodality to the NW and SE in the EL galaxies of A2199. This incongruity is tested using fifth-nearest neighbor density calculations. We interpret this discrepancy as having been caused by the interaction, which enhanced SF in the noted areas of the clusters. 236.04 The Structure of 2MASS Galaxy Clusters Jeffrey A. Blackburne1, C. S. Kochanek1, et al. 1The Ohio State University. 8:00 AM - 7:00 PM America Ballroom Foyer We use the 2MASS Redshift Survey (2MRS) sample of galaxies to refine the Kochanek et al. (2003) matched filter method of finding galaxy clusters, which takes into account each galaxy's position, magnitude, and redshift if available. The matched filter postulates a radial density profile, luminosity function, and line-of-sight velocity distribution for clusters. We use this method to search for clusters in the 2MRS sample, which is roughly complete to an extinction-corrected K-band magnitude of 13.25 and has spectroscopic redshifts for roughly 40% of the galaxies, including all brighter than K=11.25. We then use a stacking analysis to determine the average luminosity function, radial galaxy distribution, and velocity distribution of clusters in several richness classes, and use the results to update the parameters of the matched filter before repeating the cluster search. We also investigate the correlations between a cluster's richness and its velocity dispersion, its scale radius, and the magnitude of its brightest galaxy, using these relations to refine priors that are applied during the cluster search process. After the second cluster search iteration, we repeat the stacking analysis. We find a cluster luminosity function that fits a Schechter profile, though there is some evidence of an excess on the bright end due to a population of bright central galaxies. The radial number density of galaxies around a cluster center closely matches a projected NFW profile at intermediate radii, with deviations at small radii due to well-known centering issues and outside the virial radius due to the two-halo term. The velocity distributions are Gaussian in shape, with velocity dispersions that correlate strongly with richness. In addition, the scale radii correlate with richness, as do the brightest galaxy magnitudes (weakly). 237 Gamma Ray Bursts Poster Session America Ballroom Foyer 237.01 Gamma Ray Burst All-Sky Spectrometer Arielle Steger1 1University of Washington. 8:00 AM - 7:00 PM America Ballroom Foyer The Gamma Ray Burst All-Sky Spectrometer Experiment (GASE) is designed to detect radio emission from gamma ray bursts (GRB's). Radio emission from GRB’s could help us better understand the plasma physics of the blast and might also help us measure dark energy. GASE uses short-baseline interferometry with eight dipole antennas located at the MIT Haystack Observatory. These antennas measure the radiofrequency sky at 30 MHz over a 4 MHz bandwidth and are able to collect information from the entire sky. Since the entire sky is surveyed, radio frequency interference occurring at the horizon can be eliminated as a transient source. Along with the SWIFT satellite and the Gamma Ray Burst Coordinate system, we will be able measure blast time, duration and position. We are currently designing techniques to calibrate and image the full sky in radio. In addition to locating and measuring GRB’s, GASE may be able to measure dark energy due to the dispersion by the IGM. The pulse of radio emission is delayed as it travels through the intergalactic plasma, with longer wavelengths taking longer to arrive than shorter wavelengths. With the known free electron density (Ωm) we will use the dispersion measure to calculate the line of sight distance to the GRB and compare to the observed redshift to measure dark energy. 237.02 General Relativistic - Simulating Radio Emission in GRB and the FERMI outburst in the Crab Christopher Matthews1 1University of Notre Dame. 8:00 AM - 7:00 PM America Ballroom Foyer In this poster, we present the extension of the RIEMANN code to general relativistic magnetohydrodynamics. The benefits of the code include a genuinely higher order formulation leading to lower dissipation. We present several stringent test problems. We also apply the code to explain the FERMI observed outburst in the Crab by focusing on the dynamics of the termination shock in the pulsar wind nebula. Another application is associated with gamma ray bursts involving a 3D, high Lorenz factor shock interacting with fully developed 3 dimensional turbulence. 238 Evolution of Galaxies Poster Session America Ballroom Foyer 238.01 The Evolution of Isolated Elliptical Galaxies and Fossil Groups: X-ray Point Sources and Diffuse Gas Emma J. Broming1, C. Fuse1 1Rollins College. 8:00 AM - 7:00 PM America Ballroom Foyer The origin of isolated elliptical and fossil group galaxies is a frequently debated and investigated subject related to galaxy evolution. We propose that both X-ray gas and point sources can be used to study the evolution of such systems. Previous research by Fuse et al. (2011) demonstrates that a combination of X-ray gas and point sources is a reasonable indicator of the evolutionary state of a Hickson compact group (HCG). It has been postulated that the members of a compact group will interact and merge resulting in an isolated elliptical galaxy (Vikhlinin et al. 1999). Supporting this hypothesis are numerical simulations of coalescing HCGs, resulting in isolated ellipticals (Barnes 1997). Ponman et al. (1996) have theorized that a fully coalesced compact group will form a fossil group. Additionally, Ponman et al. suggest that the differentiating factor between fossil groups and isolated ellipticals is the dwarf companion gravitationally bound to a fossil group. A recent work by Fuse & Broming refutes the compact group - fossil group evolutionary connection, noting that the X-ray luminosities of isolated elliptical are more commensurate with the range of X-ray luminosities of HCGs, while fossil groups are at least an order of magnitude larger. A tight correlation in X-ray properties is noted between poor clusters and fossil groups (Fuse & Broming in prep). The implication is that isolated elliptical galaxies are likely the merger remnants of compact groups and fossil groups share an evolutionary connection to poor clusters. Further research will examine the connection between fossil groups and poor clusters. 238.02 New Results from the Survey Of a Large Area With Naco (SWAN) Kiersten Ruisard1, A. J. Baker1, G. Cresci2, R. I. Davies3 1Rutgers, the State University of New Jersey, 2Arcetri Observatory, Italy, 3Max Planck Institute for Extraterrestrial Physics, Germany. 8:00 AM - 7:00 PM America Ballroom Foyer We present and discuss the complete source catalog for SWAN, the Survey of a Wide Area with NACO, through which we have obtained near-IR imaging of 24 square arcminutes near the diffraction limit of the ESO Very Large Telescope. SWAN covers 34 fields centered on bright stars at high Galactic latitudes, which allow the use of adaptive optics corrections for improved resolution of faint sources. High-resolution images allow better separation of galactic from stellar sources and morphological classification (based on Sersic index) down to magnitudes of Ks ~ 23. Building on the work of Cresci et al. (2005), we carefully treat the anisoplanatic point spread function across each field, which requires identifying stars and fitting the point spread/radial distance relation with a Strehl ratio. We compare the total observed counts to predictions of a pure luminosity evolution (PLE) model and a numerical hierarchical structure formation model. Division of the total observed counts into late-type and early-type subsamples yields a better match for the PLE model's predictions at fainter magnitudes, consistent with an earlier analysis of a preliminary dataset (Cresci et al. 2006). We also examine close pair statistics at a higher resolution than has been possible with previous near-IR surveys and place constraints on the merger fraction down to Ks ~ 24. 238.03 The Evolution Of AGN And Their Host Galaxies At z~1 In Wide-field Multi-wavelength Surveys Andy Goulding1, DEEP2 survey team 1Harvard Smithsonian CfA. 8:00 AM - 7:00 PM America Ballroom Foyer High-quality optical spectroscopic redshift surveys are essential to enable us to fully understand the evolution of galaxies and AGN throughout cosmic history. Galaxy properties (i.e., luminosity, color, morphology, star-formation history) and AGN activity are shown to evolve strongly with time. The redshift z~1 is a crucial epoch: (1) galaxies are evolving strongly as a function of stellar mass; (2) AGN activity is extremely prevalent; (3) massive clusters are forming and (4) the red sequence is becoming established. To unambiguously determine the dominant physical processes that are driving the growth and evolution of galaxies and their central black holes at z~1 requires sensitive, wide-field multi-wavelength surveys. Following the analyses of Hickox et al. (2009), we present new results from a study combining Keck/DEIMOS optical spectroscopy, Chandra ACIS-I X-ray imaging, FIRST and NVSS radio data, and Spitzer IRAC infrared imaging available in the 6 deg^2 DEEP2 redshift survey regions. Using the extensive suite of multi-wavelength data, and through further spectroscopic follow-up using MMT/Hectospec, we have identified ~2500 of the ~20,000 DEEP2 galaxies at z~0.7--1.5 that have signatures of X-ray, IR or radio-bright AGN. Using this relatively large sample, we place new direct obscuration-independent constraints on the populations of AGN at z~1 and their host-galaxy properties, and subsequently use these results to further investigate the role of large-scale environment on galaxy evolution. 238.04 GRBs As Probes: The Galaxy Mass-Metallicity Relation at 3 10^5 cm^-3), cold (T < 20K), and have very high column densities (N ~10^23-10^25 cm^-2). These properties, along with detections of dense cores within the clouds, have led to the conclusion that IRDCs host the earliest stages of high-mass star and cluster formation. The research for my dissertation has focused on infrared dark clouds and determining their distribution in the Galaxy, their physical and chemical properties, and the role they play in high-mass star formation. In this talk I will present the results of some of this research. The Galactic distribution of a large sample of IRDCs determined from kinematic distances shows that IRDCs are largely confined to spiral arms. LTE gas masses and virial masses derived from CS (2-1) maps of a sample of IRDCs agree well with expected masses for high-mass star forming regions. I will also briefly discuss the filamentary shape of IRDCs and the "sausage instability" as a possible mechanism for the formation of high-mass star and cluster-forming cores within these filaments. The filament properties in a few cases I have observed roughly agree with theoretical predictions for this fluid instability. 217.02 MALT 90: The Millimeter Astronomy Legacy Team 90 GHz Survey James M. Jackson1, J. Foster1, K. Brooks2, J. Rathborne2, S. Longmore3 1Boston Univ., 2Australia Telescope National Facility, Australia, 3European Southern Observatory, Germany. 4:50 PM - 5:00 PM America North We present the first season results of the Millimeter Astronomy Legacy Team 90 GHz Survey (MALT90), which will image 3 mm molecular line emission from 3,000 dense star-forming cores. MALT90 exploits the capability of the ATNF Mopra 22 m telescope for fast mapping and simultaneous imaging of 16 molecular lines near 90 GHz. These molecular lines will probe the cores’ physical, chemical, and evolutionary state. The target cores are selected from the 870 micron ATLASGAL survey to host the early stages of high-mass star formation and to span the complete range of evolutionary states from pre-stellar cores, to protostellar cores, and on to H II regions. Each core will be mapped at excellent angular (40’’) and spectral (0.1 km/s) resolution. We present preliminary results for four key science projects: (1) determining the kinematic distances and Galactic distribution of dense cores, (2) establishing the distribution and evolution of angular momentum in a large sample of high-mass cores, (3) investigating the chemical evolution of dense cores, and (4) comparing the extragalactic molecular line-infrared luminosity correlations with those in Galactic cores. MALT90 will provide the definitive source list of high-mass dense cores for ALMA. 217.03 A New Molecular Arm in the Far Outer Galaxy Thomas M. Dame1, P. Thaddeus1 1Harvard-Smithsonian CfA. 5:00 PM - 5:10 PM America North We have identified in existing 21 cm surveys and subsequently traced with new CO observations a Galactic spiral arm lying well beyond the Outer Arm in the first quadrant. This arm was largely overlooked in the past, probably because it lies mainly out of the Galactic plane, its Galactic latitude increasing steadily with longitude as it follows the Galactic warp. The arm appears roughly linear in Galactic longitude, latitude, and LSR velocity and extrapolates very close to zero velocity at zero longitude. Such an l-v locus is the unmistakable signature of an arm lying well beyond the solar circle on the far side of the Galaxy. This is in marked contrast to the Outer Arm, which is clearly inside the solar circle (at positive velocities) at l < 20 deg. We have carried out a search for molecular gas in the new arm using the CfA 1.2 meter telescope and detected CO at 10 of ~200 positions. The detections are well distributed along the arm from l = 13 deg, v = -21 km/s to l = 55 deg, v = -84 km/s and coincide with most of the arm's main H I concentrations. We also fully mapped one object, finding a large molecular cloud with a radius of ~50 pc and molecular mass of ~50,000 Mo. At a mean distance of 21 kpc, the molecular gas in this arm is the most distant yet detected in the Milky Way. The new arm appears to be the continuation of the Scutum-Centaurus Arm in the outer Galaxy and a symmetric counterpart of the nearby Perseus Arm; these two may be the main density wave arms of the Milky Way, extending symmetrically from opposite ends of the central Galactic bar (Churchwell et al. 2009). 217.04 A New Technique for Mapping the Structure of the Stellar Bar and Disk of the Milky Way Galaxy Robert A. Benjamin1 1Univ. of Wisconsin-Whitewater. 5:10 PM - 5:20 PM America North Using data from the Spitzer Space Telescope GLIMPSE/Legacy project, 2MASS, and the UKIDSS Galactic plane survey, I present a new diagnostic diagram for identifying large scale stellar structures in the Milky Way Galaxy: the "longitude-magnitude" diagram. This is obtained by plotting the slopes of infared point source histogram as a function of longitude (or latitude) and magnitude. Because most sources brighter than m=12 are giants, common classes of giants, such as red clump giants, asymptotic giant branch bump, and the tip of red giant branch produce detectable changes of slopes in the source histograms. For large-scale overensities or underdensities in the Galaxy, the apparent magnitude of the inflections in these histograms changes with longitude, allowing one to map the distance to the regions of stellar over-density in the Galaxy. I demonstrate that this technique recreates previous results on the Galactic Long Bar and Triaxial Bulge and present new results on the "truncation" and warp of the stellar disk. The observed longitude-magnitude plots are also compared with synthetic longitude-magnitude plots produced with the TRILEGAL and Besancon stellar population synthesis models. 217.05 The First Detection of Blue Straggler Stars in the Milky Way Bulge Will Clarkson1, K. C. Sahu2, J. Anderson2, M. Rich3, E. Smith2, T. M. Brown2, H. E. Bond2, M. Livio2, D. Minniti4, A. Renzini5, M. Zoccali4 1Indiana University, 2Space Telescope Science Institute, 3UCLA, 4Pontifica Universidad Catolica de Chile, Chile, 5Osservatorio di Padova, Italy. 5:20 PM - 5:30 PM America North We report the first detections of Blue Straggler Stars (BSS) in the bulge of the Milky Way galaxy. Proper motions from extensive space-based observations along a single sight-line allow us to separate a sufficiently clean and well-characterized bulge sample that we are able to detect a small population of bulge objects in the region of the color-magnitude diagram commonly occupied young objects and blue strgglers. However, variability measurements of these objects clearly establish that a fraction of them are blue stragglers. Out of the 42 objects found in this region of the CMD, we estimate that at least 18 are genuine BSS. We normalize the BSS population by our estimate of the number of horizontal branch stars in the bulge in order to compare the bulge to other stellar systems. The BSS fraction is clearly discrepant from that found in stellar clusters. The blue straggler population of dwarf spheroidals remains a subject of debate; some authors claim an anticorrelation between the normalised blue straggler fraction and integrated light. If this trend is real, then the bulge extends it by three orders of magnitude in mass. Conversely, we find that the genuinely young (< 5Gy) population in the bulge, must be at most 3.3% under the most conservative scenario for the BSS population. 217.06 Model-free Mapping Of Disk And Halo Substructure In SDSS III Mario Juric1, A. Bonaca2 1Harvard University, 2Yale University. 5:30 PM - 5:40 PM America North The 8th release of the Sloan Digital Sky Survey featured ~2000 deg^2 of new imaging, largely in the southern Galactic hemisphere. This new imaging allows us to perform model-free examination of North-South and East-West symmetry of the Milky Way and detect and characterize structures in the Galactic disk and halo. Using these data, we show that the Virgo overdensity is significantly more extended (~3000deg2) than previously estimated. However, we demonstrate it is unlikely to be a global feature of the halo, such as triaxiallity or halo ellipsoid tilt. Combined with previously published measurement of kinematics, the Virgo overdensity is consistent with a strongly disrupted tidal stream observed near perigalacticon. Secondly, we map the extent of the "thick disk asymmetry", a major ring-like feature in the thick disk at 3-5 kpc (heliocentric) towards the Galactic anticenter. While clearly detected in the nearly-synoptic SDSS III maps, its nature remains unclear; a merger remnant, a warp in the disk, or an effect of spiral structure may all serve as explanations of its origin. Follow-up observations are ongoing to better understand its nature. 217.07 Evidence for a Mass-Transfer Origin for the Long-Period Blue Straggler Binaries in the Old Open Cluster NGC 188 Robert D. Mathieu1, A. M. Geller2 1Univ. of Wisconsin, 2Northwestern University. 5:40 PM - 5:50 PM America North The discovery of many blue straggler binaries with long orbital periods (of order 1000 days) in the old open cluster NGC 188 has focused attention on three theoretical models for blue straggler formation: i) mass transfer in binary stars, ii) stellar collisions during dynamical encounters of multiple star systems, or iii) mergers of inner binaries in primordial triples driven by the Kozai mechanism. A critical discriminant between these formation channels are the secondary stars of blue straggler binaries. The merger and collision scenarios predict main-sequence secondary stars, while the mass-transfer scenario predicts white dwarf secondary stars. We present the observed secondary-mass distribution for the long-period NGC 188 blue stragglers. The distribution is peaked around a mean value of 0.55 solar masses with a standard deviation of 0.2 solar masses. A Monte Carlo analysis rules out the hypothesis that this distribution is populated by main-sequence companions chosen randomly from a standard initial mass function (at > 99% confidence level)or a flat mass-ratio distribution (at the 95.5% confidence level), suggesting that many of the companions are likely stellar remnants, such as white dwarfs. Comparisons to a sophisticated N-body open cluster model reveal that the observed distributions of companion mass and eccentricity for the long-period NGC 188 blue straggler binaries are not consistent with an origin in collisions, as collision products are predicted to have significantly more massive companions and higher eccentricities than are observed. These findings are consistent with a mass-transfer origin for most, and possibly all, of the long-period blue straggler binaries in NGC 188. We gratefully acknowledge funding from the National Science Foundation under grant AST-0908082, and our collaborators of the WIYN Open Cluster Study. 218 Extrasolar Planets: Detection and Characterization Oral Session America Central 218.01 First Estimate of the Exoplanet Population from Kepler Observations William J. Borucki1, D. G. Koch1, N. Batalha2, D. Caldwell3, E. W. Dunham4, T. N. Gautier III5, S. B. Howell1, J. M. Jenkins3, G. W. Marcy6, J. Rowe1, D. Charbonneau7, D. Ciardi8, E. B. Ford9, J. L. Christiansen3, J. Kolodziejczak10, A. Prsa11 1NASA Ames Research Center, 2San Jose State University, 3SETI Institute, 4Lowell Observatory, 511Jet Propulsion Laboratory, Calif. Institute of Technology, 6University of California, 7Harvard-Smithsonian Center for Astrophysics, 8Exoplanet Science Institute/Caltech, 9Uniersity of Florida, 10MSFC, 11Villanova University. 4:30 PM - 4:40 PM America Central William J. Borucki, David G. Koch, Natalie Batalha, Derek Buzasi , Doug Caldwell, David Charbonneau, Jessie L. Christiansen, David R. Ciardi, Edward Dunham, Eric B. Ford, Steve Thomas N. Gautier III, Steve Howell, Jon M. Jenkins, Jeffery Kolodziejczak, Geoffrey W. Marcy, Jason Rowe, and Andrej Prsa A model was developed to provide a first estimate of the intrinsic frequency of planetary candidates based on the number of detected planetary candidates and the measured noise for each of the 156,000 observed stars. The estimated distributions for the exoplanet frequency are presented with respect to the semi-major axis and the stellar effective temperature and represent values appropriate only to short-period candidates. Improved estimates are expected after a Monte Carlo study of the sensitivity of the data analysis pipeline to transit signals injected at the pixel level is completed. 218.02 Spitzer Results toward Validation of Super-Earth Candidates Identified by Kepler Sarah Ballard1, D. Charbonneau1, J. Desert1, F. Fressin1, Kepler Team 1Harvard-Smithsonian Center for Astrophysics. 4:40 PM - 4:50 PM America Central We present selected results of a Warm Spitzer campaign to observe exoplanetary candidates identified by the Kepler mission. The Spitzer light curves provide an independent test of the planetary nature of these candidates. We combine the results of the Spitzer observations with those from BLENDER (a software package to model Kepler light curves as astrophysical false positives) and spectroscopy (where available) to consider the planetary status of several candidates with putative radii between 1.5 and 3 times that of the Earth. Particularly in the cases of candidates with masses too small to be confirmed with radial velocity measurements, Spitzer observations provide crucial information about the planetary status of a given candidate, namely by establishing whether the transit depth is achromatic. 218.03 The GJ 436 System: Directly Determined Exoplanetary Diameter and Fundamental Stellar Parameters Kaspar von Braun1, T. S. Boyajian2, S. R. Kane1, G. T. van Belle3, D. R. Ciardi1, M. Lopez-Morales4, H. A. McAlister2, T. J. Henry2, G. Schaefer5, T. A. ten Brummelaar5, S. Ridgway6, L. Sturmann5, J. Sturmann5, N. H. Turner5, C. Farrington5, P. J. Goldfinger5 1Caltech, 2Georgia State University, 3ESO, Germany, 4Institut de Ciencies de L'Espai, Spain, 5CHARA, 6NOAO. 4:50 PM - 5:00 PM America Central GJ 436 is a nearby M dwarf hosting a transiting Neptune-mass exoplanet in a 2.6 day orbit. We use the CHARA interferometric array to determine the stellar angular diameter. Coupled with trigonometric parallax values and literature photometry, we obtain direct estimates of the stellar physical size and surface temperature (through spectral energy distribution fitting). Finally, literature measurements of the depth of transit provide a direct estimate of the planetary diameter. We discuss how our empirical results and related consequences compare with previously published values of the stellar and planetary parameters of the GJ 436 system. 218.04 Analysis of HAT-P-2b Warm Spitzer Full Orbit Light Curve Nikole Lewis1, H. Knuston2, A. P. Showman1, J. J. Fortney3, E. Agol4, A. Burrows5, D. Charbonneau6, N. B. Cowan7, D. Deming8, J. Desert6, J. Langton9, G. Laughlin3, K. J. Mighell10 1University of Arizona, 2UC Berkeley, 3UC Santa Cruz, 4University of Washington, 5Princeton University, 6Harvard University, 7Northwestern University, 8NASA Goddard, 9Principia College, 10NOAO. 5:00 PM - 5:10 PM America Central The Spitzer warm mission has already greatly expanded the field of exoplanet characterization with over 3000 hours of time dedicated to exoplanet observations.  Observations of eclipsing systems with Spitzer are at the heart of these advances, as they allow us to move beyond simple mass and period estimates to determine planetary radius, dayside emission, and emission variations as a function of orbital phase.  The eclipsing system HAT-P-2 is of special interest because the massive Jovian sized planet in this system is on a highly eccentric orbit (e=0.5171). Because HAT-P-2b's orbit is eccentric, the planet is subject to time variable heating and probable non-synchronous rotation.  Circulation patterns that we expect to develop in HAT-P-2b's atmosphere will likely vary with both planetary local time and orbital phase. Here we present an analysis of a full orbit light curve from the HAT-P-2 system obtained during the most recent cycle of the Spitzer warm mission and discuss the constraints it imposes on the atmospheric circulation of HAT-P-2b. Support for this work was provided by NASA. 218.05 Young Low-Mass Companion Candidates from the PTF Orion Planet Search Project Julian C. Van Eyken1, D. R. Ciardi1, R. L. Akeson1, C. A. Beichman1, A. F. Boden2, K. von Braun1, J. Crepp2, B. J. Fulton3, D. M. Gelino1, D. W. Hoard4, S. B. Howell5, S. R. Kane1, P. Plavchan1, S. V. Ramírez1, L. M. Rebull4, A. Shporer6, J. R. Stauffer4, PTF Collaboration 1NExScI, Caltech, 2Caltech, 3LCOGT, 4Spitzer Science Center, Caltech, 5NOAO, 6LCOGT/UC Santa Barbara. 5:10 PM - 5:20 PM America Central The PTF Orion project is a part of the Palomar Transient Factory (PTF), a photometric survey for astronomical transients being undertaken with a dedicated wide-field CCD array installed on the Palomar 48" telescope. The camera consists of a 12-CCD array with a total nominal 7.8 square-degree field of view and 1-arcsecond pixels. The Orion project is based on intensive high-cadence time-series observations of a single pointing in the 7-10Myr old 25 Ori region, with the aims of searching for planets around stars at these young ages; studying eclipsing binary systems for testing star formation and evolution models; characterising stellar activity and rotational periods at this age range; and characterising previously unknown young stars in the region. Among the results from 40 nights of observing from December 2009 and January 2010 are several late-type (likely M0 or later) sources which show interesting shallow (~5% or less) eclipses. One in particular appears to be a variable weak-lined T-Tauri star with regular ~3%-depth transit-like features at a period of 0.4485d, which may be indicative of a sub-stellar companion. We present initial results from photometric and spectroscopic followup of this object. 218.06 A Search for H-alpha Absorption in Exoplanetary Exospheres Adam G. Jensen1, S. Redfield1, W. D. Cochran2, M. Endl2, L. Koesterke2, T. S. Barman3 1Wesleyan University, 2University of Texas, 3Lowell Observatory. 5:20 PM - 5:30 PM America Central The number of exoplanets with detected atmospheres is rapidly increasing. Particularly intriguing are detections of hydrogen that are attributed to the upper, unbound portion of their atmospheres (i.e. the “exospheres”) and indicate that some gas giants may be evaporating. Exospheric hydrogen has only been detected in Lyman-alpha, which, as with all single line detections, only provides limited information about physical conditions such as density and temperature. A much better understanding of exospheres and their evolution would be gained through a constraint on H-alpha. We have obtained more than 100 total hours of spectroscopic observations with the Hobby-Eberly Telescope of five different exoplanetary targets, with the goal of deriving transmission spectra of exoplanetary atmospheres; two of these targets have had their exospheres detected in Lyman-alpha. Here we report on our search for H-alpha absorption in these exospheres, and the implications for their physical conditions and evolution. This work is supported by the National Science Foundation through an Astronomy and Astrophysics Research Grant (AST-0903573). The Hobby-Eberly Telescope is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen and is named in honor of its principal benefactors, William P. Hobby and Robert E. Eberly. 218.07 Stacking the Hay: Modeling the Worst-Case Scenario for Exozodiacal Clouds Christopher C. Stark1, K. Cahoy2 1Carnegie Institution of Washington, 2MIT. 5:30 PM - 5:40 PM America Central Our solar system is home to a tenuous disk of dust created by collisions between and outgassing of comets, asteroids, and Kuiper Belt objects. The inner ~AU of this disk, the zodiacal cloud, is gravitationally perturbed by Earth, which traps dust in exterior mean motion resonances to create an overdense circumsolar ring of dust. Future attempts to directly image extrasolar Earth-like planets will likely have to contend with analogous "exozodiacal" dust disks, which may contain similar asymmetric rings of dust. We model the interactions between planets and exozodiacal dust disks to predict the resonant ring structures created by single planets on circular orbits. We use a new collisional grooming algorithm to, for the first time, produce models of exozodiacal clouds that simultaneously and self-consistently handle dust grain dynamics, including resonant interactions with planets, and grain-grain collisions. The collisional grooming algorithm allows us to produce multi-grain size exozodi models that range in optical depth from one "zodi" to hundreds of zodis. We investigate a range of planet masses, planet semi-major axes, and dust compositions, and synthesize multi-wavelength images of our models at a variety of viewing geometries. Our results place realistic upper bounds on the degree of resonant structure and asymmetry to be expected in exozodiacal dust disks; this library of "worst case" exozodi models can be used to simulate the detectability of Earth-like planets embedded in structured debris disks using proposed telescopes. 218.08 Finding the Needle: How To Use A Space-borne Coronagraph To Detect Exoplanets Embedded In Debris Disks Kerri Lynn Cahoy1, C. C. Stark2, O. Guyon3, M. S. Marley4, J. J. Fortney5 1MIT, 2Carnegie Institute of Washington, DTM, 3University of Arizona, 4NASA Ames Research Center, 5University of California, Santa Cruz. 5:40 PM - 5:50 PM America Central A spacecraft in a stable orbit that carries a telescope and high-performance coronagraph system can block out the light from a bright parent star in the optical well enough to take images of exoplanets around the star that shine with reflected starlight. However, in addition to exoplanets, the parent stars are also enveloped by debris disks. The presence of debris disks can either strengthen the case for exoplanet detection, if there are structures in the disk that suggest the formation of an exoplanet, or they can weaken the case for exoplanet detection, if the disks are so bright that neither disk structure nor the presence of an exoplanet can be detected in them. The contribution of the exoplanet itself to the image is a function of wavelength, size of the exoplanet, separation between the exoplanet and the parent star, and composition of the exoplanet's atmosphere. For a sun-like parent star at a distance of 10 parsecs, we consider the combined effect of a variety of debris disk structures and exoplanet spectra for both Earth-like and gas-giant exoplanets at planet-star separations of 0.5 AU, 1 AU, 5 AU, and 10 AU. For this work, we currently simulate a high-performance Phase-induced Amplitude Apodization (PIAA) coronagraph at several wavelengths in the optical and with telescope primary diameters ranging from 1.5 to 4 meters. Our results, in the form of signal-to-noise ratios of the model exoplanet and debris disk systems, predict which combinations of debris disk, exoplanet, and instrumentation parameters will be detectable for reasonable integration times, helping to inform more detailed future simulations and define mission and instrumentation specifications. 219 Supernovae, PNe, Evolved Stars and other Topics Oral Session St. George CD 219.01 Type Ia Supernovae at z>1.5 from the HST Multi-Cycle Treasury Surveys Steven A. Rodney1, A. G. Riess1, L. Strolger2, H. C. Ferguson3, S. Casertano3, A. Koekemoer3, T. Dahlen3, N. A. Grogin3, J. Hjorth4, O. Graur5, B. Mobasher6, C. Scarlata7, B. J. Weiner8, S. M. Faber9, M. Postman3, CANDELS Collaboration, CLASH Collaboration 1The Johns Hopkins University, 2Western Kentucky University, 3Space Telescope Science Institute, 4University of Copenhagen, Denmark, 5Tel Aviv University, Israel, 6University of California, Riverside, 7University of Minnesota, 8University of Arizona, 9University of California, Santa Cruz. 4:30 PM - 4:40 PM St. George CD Presenting early results from the joint CANDELS+CLASH Supernova survey, we describe the discovery and spectroscopic classification of a Type Ia Supernova (SNIa) at z=1.55, matching the highest redshift for a confirmed SNIa on record. This HST Treasury survey has the potential to detect and characterize SNIa out to redshift 2 and beyond, building up a sample of SNIa in the era of deceleration, where dark energy effects are expected to be minimal. Comparing these SNe to low-redshift counterparts, we will be able to test for SNIa evolution effects that could introduce systematic biases in SN cosmology. Tracing the SNIa rate to z>2 will clarify the still controversial delay time distribution measurement and put new constraints on SNIa progenitor models. 219.02 An Unbiased Statistical Survey of Ibc Supernova Host Abundances Nathan Sanders1, A. M. Soderberg1, E. M. Levesque2 1Harvard University, 2University of Colorado at Boulder. 4:40 PM - 4:50 PM St. George CD Metallicity is a key parameter of the progenitors of Type Ib/c core-collapse supernovae. It has profound consequences for constraining their progenitor model and their connection to long-duration GRBs. Moreover, it constrains their delay-time distribution, which is imperative to modeling galactic chemical evolution. We employ deep follow-up observations from the LDSS-3 long-slit spectrograph of the Magellan telescopes to study a growing sample of more than two dozen Ibc host galaxies. These supernovae are not subject to bias due to the galaxy luminosity-metallicity relationship, as they were selected only from untargeted transient searches including Pan-STARRS, Nearby Supernova Factory, and the SDSS-II Supernova Survey. We employ strong line methods to determine the host galaxy oxygen abundance and are developing new statistical methods to produce an accurate understanding of the associated uncertainties, both random and systematic. We use the 2D long-slit spectra to provide additional information on the progenitor environment by exploring the abundance distribution as a function of host galaxy radius. We compare our sample to the host galaxies of SNe from targeted surveys to characterize the potential effects of bias. We compare to GRB hosts to explore the connection between Ib/c supernovae and long-duration GRB progenitors. 219.03 Searching for the Progenitors of Type Ia Supernova Rosanne Di Stefano1 1Harvard-Smithsonian CfA. 4:50 PM - 5:00 PM St. George CD Type Ia supernovae are important cosmic probes. To understand and eliminate systematic uncertainties, it is important to know the nature and characteristics of their progenitors. I will talk about recent progress that may allow us to search for and identify progenitors within our own Galaxy, using data from wide-field surveys such as SDSS, Pan-STARRS, and LSST. We will consider the nuclear-burning phase that is expected to occur in both single-degenerate and double-degenerate models. We will also consider the expected characteristics just prior to explosion in the new class of spin-up/spin-down models. Finally, we will discuss the prospects for finding the progenitors in external galaxies, in light of the fact that most do not appear as x-ray sources, or else have a low duty cycle of x-ray activity. 219.04D Magnetic Fields And Developing Asymmetries In Circumstellar Masers Nikta Amiri1, W. Vlemmings2, H. van Langevelde3, A. Kemball4 1Leiden Observatory, Netherlands, 2Argelander Institute for Astronomy, University of Bonn, Germany, 3Joint Institute for VLBI in Europe, Netherlands, 4Department of Astronomy, University of Illinois. 5:00 PM - 5:20 PM St. George CD Maser emission occurs in different regions of the circumstellar envelopes (CSEs) of evolved stars and can be studied at high angular resolution using radio interferometers. These masers are useful probes of the dynamics and kinematics of the outflow from AGB stars. Moreover, masers can be important tracers of the magnetic field strength and morphology at various distances from the central stars. It is expected that the magnetic field plays an important role in transforming spherically symmetric asymptotic giant branch (AGB) stars into a-spherical planetary nebulae (PNe). Theoretical modeling indicated that magnetically collimated jets may be responsible for the formation of the a-spherical PNe. Water fountain sources are a class of post-AGB objects in which H2O masers indicate high velocity collimated jets. Our radio interferometric observations indicate that asymmetries are also present in the OH maser region of the envelope. We performed kinematical reconstruction in order to understand the distribution of OH masers in the CSEs of these stars. Our results show that the OH masers could have either equatorial or bi-conical distribution. Additionally, the observations reveal significant field strength for the OH maser region of these objects, which show the possible role of the magnetic field in collimating the CSEs. At distances close to the central stars, between the photosphere and the dust formation zone, SiO masers occur. SiO maser polarimetry has been performed for Mira variables and supergiants and seems to indicate dynamically significant and ordered magnetic fields. We extended these studies and performed VLBA SiO maser polarization observations of objects with more extreme mass-loss, in order to understand the origin of the transition between the AGB and PNe. These observations will enable us to understand the SiO emission mechanisms and possibly distinguish between competing models on the origin of the SiO maser polarization. 219.05 An Improved Tlusty Model Of Cataclysmic Variable Accretion Disk Annuli. Albert P. Linnell1, I. Hubeny2 1Univ. of Washington, 2Univ. of Arizona. 5:20 PM - 5:30 PM St. George CD The Hubeny TLUSTY and SYNSPEC programs have been used in several studies of Nova-like Cataclysmic Variable stars, especially models of their accretion disks. Tabulations of column masses for the individual annuli (which are always optically thick) listed values in disagreement with theoretical models in the literature (e.g., Lasota, 2001, NAR, 45, 449, Fig. 1). The discrepancy arose from an inadequate treatment of convection in TLUSTY (which had been developed with particular attention to radiation-dominated accretion disks). A new version of TLUSTY, developed by Hubeny, corrects the discrepancy and produces an insignificant change in our published conclusions. We illustrate the results for our study of RW Sextantis (Linnell et al., 2010, ApJ,719,271). 219.06 Spectroscopic Separation of Solar Wind Charge Exchange, Local Bubble, and Nearby Supernova Remnant X-rays: Diffuse X-ray Spectrometer Recent Results Jeffrey P. Morgenthaler1, R. J. Edgar2, W. T. Sanders3, R. K. Smith2, D. Koutroumpa4, D. B. Henley5, R. L. Shelton5, I. P. Robertson6, M. R. Collier4, T. E. Cravens6 1Planetary Science Institute, 2Harvard-Smithsonian Center for Astrophysics, 3NASA Headquarters, 4NASA/GSFC, 5University of Georgia, 6University of Kansas. 5:30 PM - 5:40 PM St. George CD The Diffuse X-ray Spectrometer (DXS) was a Space Shuttle Payload of Opportunity that flew in 1993. DXS measured the spectrum of the diffuse X-ray background (DXRB) between 150 eV and 284 eV (the 1/4 keV band) using a Bragg crystal spectrometer. Higher order Bragg reflections included the OVII and OVIII features. The counting statistics and spectroscopic resolving power of the DXS measurements have yet to be rivaled in the 1/4 keV band. DXS had a 15°x15° FOV that was repeatedly scanned over a ~140° arc in the Galactic plane centered roughly toward the Galactic anti-center. The Vela-Puppis and the Monogem ring supernova remnants were studied, as well 3 adjacent regions typical of the DXRB. During the 5-day Shuttle flight, the total sky-looking DXS count rate unexpectedly dropped by 20%, suggesting a significant and variable local source of X-rays, likely generated by the solar wind charge exchange mechanism (SWCX) in the geocorona and/or a passing coronal mass ejection. We use this unique dataset to: (1) Show that a state-of-the-art heliospheric SWCX model compares reasonably well to the DXS DXRB spectrum in the 190-284 eV range, but falls short in the 150-190 eV range. (2) Spectroscopically resolve the OVII forbidden and resonance lines, showing that the resonance line is somewhat stronger. This confirms there is a contribution to the DXRB from a source other than the SWCX. (3) Present spectra of the Vela-Puppis and Monogem regions cleaned of all foreground X-ray emission and compare to standard collisional ionization equilibrium plasma models. The discrepancies between the models and data highlight the need for continued progress in understanding the L-shell ions of Mg, Si, S and the M-shell ions of Fe. (4) Present the first isolated spectrum of the SWCX in the 1/4 keV band that resolves lines/line complexes. 219.07 Ejecta Knot Evolution in Cassiopeia A John Rutherford1, E. Figueroa1, D. Dewey1, S. Trowbridge1, K. Sato1, F. Bastien2 1MIT, 2Vanderbilt. 5:40 PM - 5:50 PM St. George CD We investigated the spectral evolution of the bright ejecta knots in Cassiopeia A to better understand how these coherent masses interact with shocks and physically change. With over a decade of outstanding Chandra observations, we were able to utilize widely spaced epochs to look for evolution of the supernova remnant in the X-ray band. We present our findings of how such modeled plasma parameters as the temperature and non-equilibrium ionization age changed over ten years of the several hundred year old remnant's lifetime, as well as how these parameters correlate with the estimated time since shocked. Careful analyses of background contamination and model parameter correlations were also considered. High resolution dispersed data were taken to complement the ACIS observations, yielding a unique set of low density plasma measurements. We find disagreements between the temperatures derived by the non-equilibrium ionization model using the ACIS data and newly released plasma emission models, which utilize the Si triplet ratios from the dispersed data. 219.08 A New Evolutionary Phase of Supernova Remnant 1987A Sangwook Park1, S. A. Zhekov2, D. N. Burrows3, J. L. Racusin4, D. Dewey5, R. McCray6 1University of Texas at Arlington, 2Space and Solar-Terrestrial Research Institute, Bulgaria, 3Pennsylvania State University, 4NASA/GSFC, 5MIT, 6University of Colorado. 5:50 PM - 6:00 PM St. George CD We have been monitoring the supernova remnant (SNR) 1987A using our Chandra observations since 1999. Here we report on the latest change in the soft X-ray light curve of SNR 1987A. For the last ~1.5 yr, the soft X-ray flux has been nearly constant at f_X ~ 5.7 x 10^-12 erg cm^-2 s^-1 (L_X ~ 3.6 x 10^36 erg s^-1). This remarkable change in the soft X-ray light curve suggests that the shock is now interacting with a ``decreasing'' density structure after interacting with an increasing density over ~10 yr prior to day ~8000. Possible interpretations may include an intriguing scenario that the shock is now probably propagating beyond a density peak of the inner ring. We briefly discuss some future prospects of our Chandra monitoring observations. 220 Cosmology Oral Session America South 220.01 Nonsingular Big-Bounce Cosmology Without Inflation From Torsion Nikodem J. Poplawski1 1Indiana University. 4:30 PM - 4:40 PM America South We propose a simple cosmological scenario which explains why our Universe appears spatially flat, homogeneous and isotropic. We use the Einstein-Cartan-Sciama-Kibble (ECSK) theory of gravity that naturally extends general relativity to include the intrinsic spin of fermionic matter. The torsion of spacetime generates gravitational repulsion in the early Universe filled with quarks and leptons, preventing a cosmological singularity: the Universe expands from a state of minimum but finite radius. We show that the dynamics of the closed Universe immediately after this state solves the flatness and horizon problems in cosmology because of a negative and extremely small in magnitude torsion density parameter, $\Omega_S=-10^{-69}$. The ECSK gravity, which does not introduce additional matter fields, therefore provides a plausible alternative to cosmic inflation. The observed spectrum of cosmological perturbations suggests that the contraction of our Universe preceding the bounce at the minimum radius may correspond to the dynamics of matter inside a collapsing black hole existing in another universe. 220.02 Is the 2MASS Dipole Convergent? Maciej Bilicki1, M. Chodorowski1, G. A. Mamon2, T. H. Jarrett3 1Nicolaus Copernicus Astronomical Center, Poland, 2Institut d'Astrophysique de Paris, France, 3Infrared Processing and Analysis Center, Spitzer Science Center, Jet Propulsion Laboratory, California Institute of Technology. 4:40 PM - 4:50 PM America South We study the growth of the clustering dipole of galaxies as a function of the limiting flux of the sample from the Two Micron All Sky Survey (2MASS). Contrary to some earlier claims, we find that the dipole does not converge before the completeness limit of the 2MASS Extended Source Catalog, i.e. up to 13.5 mag in the near-infrared K_s band (equivalent to an effective distance of 300 Mpc/h). We compare the observed growth of the dipole with the theoretically expected, conditional one (i.e., given the velocity of the Local Group relative to the CMB), for the Lambda-CDM power spectrum and cosmological parameters constrained by WMAP. The observed growth turns out to be within 1-sigma confidence level of its theoretical counterpart once the proper observational window of the 2MASS flux-limited catalog is included. For a contrast, if the adopted window is a top-hat, then the predicted dipole grows significantly faster and converges (within the errors) to its final value for a distance of about 300 Mpc/h. By comparing the observational windows, we show that for a given flux limit and a corresponding distance limit, the 2MASS flux-weighted window passes less large-scale signal than the top-hat one. We conclude that the growth of the 2MASS dipole for effective distances greater than 200 Mpc/h is only apparent. On the other hand, for a distance of 80 Mpc/h (mean depth of the 2MASS Redshift Survey) and the Lambda-CDM power spectrum, the true dipole is expected to reach only ~80% of its final value. Eventually, since for the window function of 2MASS the predicted growth is consistent with the observed one, we can compare the two to evaluate beta = (Omega_m)^{0.55} / b. The result is beta = 0.38+-0.02 (1-sigma errors), which gives an estimate of the density parameter Omega_m = 0.20+-0.07. 220.03D A Method for 21cm Power Spectrum Estimation in the Presence of Foregrounds Adrian Liu1, M. Tegmark1 1Massachusetts Institute of Technology. 4:50 PM - 5:10 PM America South In coming years, 21cm tomography has the potential to probe the Epoch of Reionization, the preceding Dark Ages, and fundamental physics with unprecedented levels of accuracy. Before this potential can be realized, however, 21 cm tomography will have to deal with the issue of foreground contamination. We present a unified matrix formalism for performing foreground cleaning and power spectrum estimation in redshifted 21 cm tomography experiments. We show that the traditional cleaning method of subtracting low-order polynomials from foreground spectra can lead to substantial mode-mixing and biases in the power spectrum, and that an inverse variance weighting of foregrounds eliminates these problems. The inverse variance method can be intuitively understood to be a high-pass filter in the line-of-sight direction, and the resulting post-subtraction power spectrum error bars are smaller than those obtained by traditional methods. This reduction of power spectrum errors will aid low-frequency radio arrays in their quest to obtain the tightest constraints on cosmological parameters as well as on reionization astrophysics. 220.04 Fast Power Spectrum Analysis and Foreground Subtraction for 21 cm Cosmology Joshua S. Dillon1, A. Liu1, M. Tegmark1 1Massachusetts Institute of Technology. 5:10 PM - 5:20 PM America South While the highly redshifted 21 cm sky promises a vast well of information about the universe during and before reionization, tapping it will require powerful radio telescopes and a comprehensive method of eliminating foreground contaminants that dominate the cosmological signal. However, the sheer quantity of data expected will itself present an important algorithmic challenge to any foreground subtraction technique. We expand upon a combined scheme for power spectrum estimation and foreground cleaning recently adapted from CMB and galaxy surveys that is designed to retain all cosmological information. This technique nominally requires inverting the enormous matrix that encodes the correlations between foreground contributions to the measured 21 cm brightness temperatures at different positions and redshifts. In doing so, it takes advantage both of the strong correlations between the spectrally smooth foregrounds along the line of sight and of their clustering perpendicular to the line of sight. By exploiting the symmetries of radio foregrounds and the fast Fourier transform, we show that foreground subtraction, power spectrum estimation, and Fisher information can all be computed in O(NlogN), where N can be of the order of a million or bigger. This will enable future experiments to completely analyze very large datasets without loss of information. It also allows us to efficiently assess the precision with which current and future radio interferometers can measure the cosmological power spectrum and can serve to guide the optimal design of interferometers specially purposed for 21 cm cosmology. 220.05 An Experiment To Search For The 21-cm All-sky Reionization Spectral Signal. Jeffrey Peterson1 1Carnegie Mellon Univ.. 5:20 PM - 5:30 PM America South As the z~10 reionization proceeded the sky brightness due to 21-cm emmission/absorbtion changed by at least 10 mK. A new instrument to measure this all-sky signal will be described. The instrument features a set of scaled corrugated antennas and a full beam black body calibrator. The planned site for the experiment is Isla Guadaupe, Mexico. Tests of scale model antennas and calibrators will be presented. 220.06 High-Redshift Gamma-Ray Bursts and Star Formation: Present and Future Constraints Derek B. Fox1 1Penn State University. 5:30 PM - 5:40 PM America South I will discuss the present status of searches for the highest-redshift gamma-ray bursts using the Swift satellite and follow-up ground-based telescopes including the Gemini Observatory. Gamma-ray bursts can serve as valuable probes of star-forming regions and the evolving ionization of the intergalactic medium at these redshifts; moreover, the redshift distribution of the bursts themselves serves as the unique tracer of high-redshift star formation that is independent of galaxy luminosity-function uncertainties. I will address the current status of the GRB-inferred star formation rate in the context of other measures, and discuss the prospects for refining this GRB metric in the near future with Swift, and later this decade, via the proposed JANUS Explorer mission. 221 Prospects for High Resolution Low Energy X-ray Spectroscopy Special Session Staffordshire 221.01 High Resolution X-ray Spectroscopy of AGN: Recent Results and Future Advances Herman L. Marshall1 1MIT. 4:30 PM - 4:42 PM Staffordshire I will summarize findings from the past ten years of high resolution X-ray spectroscopy of AGN using Chandra and XMM-Newton, concentrating on the energy range from 0.1 to 1.0 keV. The main scientific findings concentrate in three broad categories: 1) measuring photoexcited gas at mild outflow or transverse speeds via absorption, 2) tracking photoexcited gas in emission outside the nucleus, and 3) probing the inner accretion disk via relativistically broadened emission lines. I will show how these studies may be advanced with new observations at high resolution and improved effective area. This work has been funded in part by National Aeronautics and Space Administration (NASA) through the Smithsonian Astrophysical Observatory (SAO) contract SV3-73016 to MIT for support of the Chandra X-Ray Center (CXC), which is operated by SAO for and on behalf of NASA under contract NAS8-03060. 221.02 The WHIM in X-rays: current evidence and future prospects Fabrizio Nicastro1 1Smithsonian Astrophysical Observatory. 4:42 PM - 4:54 PM Staffordshire I will present the current evidence of the WHIM in the X-rays, including preliminary results from our long Chandra observation of 'The Best WHIM Target in the Sky" (to be taken in April 2011). During the second part of my talk, I will focus on the need for higher resolution and larger throughput X-ray spectrometers, and on the instrumental parameters that need to characterize this instrumentation, for us to be able to systematically detect and study the Warm-Hot Intergalactic Medium in the band in which the electronic transitions expected from this medium are most copiously present: the X-rays. 221.03 High-Resolution Spectroscopic Studies of the Intergalactic Medium J. Michael Shull1 1Univ. of Colorado. 4:54 PM - 5:06 PM Staffordshire Theoretical studies of cosmological structure formation predict that a large fraction of primordial baryons have not accreted onto galaxies. Instead, they are distributed between the galaxies in a complex intergalactic medium (IGM) structured in filaments and voids. Ranging in temperature from 10,000 K to several million degrees, this gas has a distribution of ions determined by collisional ionization and photoionization by EUV and X-ray backgrounds. Ultraviolet spectral surveys (Hubble, FUSE) have detected the hot IGM in resonant absorption lines of trace species (H I, O VI, N V, Ne VIII). However, a significant fraction (40-50 percent) of the baryons has eluded detection. They may reside in million-degree gas produced by cosmological shocks, galactic winds, and virialized circumgalactic gas. Searching for this hot, metal-contaminated gas will require high-throughput X-ray spectrographs, to detect narrow (50-100 km/s) absorption lines from the key ions (C V, N VI, O VII, O VIII, Ne IX) that dominate million-degree plasmas. Such X-ray missions need spectral resolution exceeding 100 km/s and a combination of effective area and exposure time to reliably detect these spectral features. 221.04 Blast our resolve or resolve our blast? Jeremy J. Drake1 1Harvard-Smithsonian, CfA. 5:06 PM - 5:18 PM Staffordshire High-resolution Chandra and XMM-Newton grating spectra of bright novae in outburst, together with Swift low-resoluton monitoring, have provided remarkable new insights into the nature of the explosions themselves, and of the physical state and chemical composition of the residual "supersoft sources" that emerge from within an expanding shell of ejecta. One surprise is how different novae have appeared in X-rays, with the consequence that a unified picture of these explosions and their aftermath remains elusive. Early-phase hard X-ray emission, and supersoft source spectra that exhibit wild variations, are two examples of phenomena that remain unexplained. Further progress is hampered by the need to observe a larger sample of events at high-resolution and higher cadence to capture and probe the variety of behaviour observed. An instrument with an order of magnitude more power than current observatories would be poised to make the next breakthrough. 221.05 High Resolution Soft X-ray Spectroscopy for Young Stellar Objects Nancy S. Brickhouse1 1Harvard-Smithsonian, CfA. 5:18 PM - 5:30 PM Staffordshire Young stellar objects exhibit X-ray emission throughout their evolution. The emission above about 1 keV is primarily produced from coronal structures and flares, indicating that magnetic activity is present from early on. For stars that are still actively accreting, X-ray accretion signatures of accretion are only distinguishable at low energies in high resolution grating spectra from Chandra and XMM-Newton. The accretion shock itself is identified in only a few of these sources through line ratio diagnostics for high electron density at relatively low temperature. However, a soft X-ray excess, compared with main sequence and weak-line T Tauri stars, is found in all the Classical T Tauri grating targets. This emission presents as excess O VII. Exactly what produces the soft excess and how it relates to the shock and to the photospheric accretion hot spot is unclear without additional diagnostics. Shocks in jets and winds, as well as magnetic heating at the hot spot are possible. High resolution soft X-ray spectroscopy will allow us to determine the velocity structure from line profiles, the density and volume from line diagnostics for a range of soft X-ray emitting temperatures, and the absorbing column density of pre-shock gas as a function of shock structure. The author's work is supported by the Chandra X-ray Observatory through a NASA contract with the Smithsonian Astrophysical Observatory. 221.06 Whimex: Exploring The High Temperature Intergalactic Medium In This Decade Webster C. Cash, Jr.1, WHIMex Science and Instrument Teams 1Univ. of Colorado. 5:30 PM - 5:42 PM Staffordshire Observations of the WHIM strongly indicate that a large percentage of the baryons in the Universe reside in a hot phase, ionized beyond the reach of ultraviolet observatories like FUSE and HST. Chandra and XMM are giving us tantalizing indications that a sufficiently powerful soft x-ray spectrograph could study these gasses in detail. The WARM Hot Intergalactic Medium Explorer is a response to that need. This presentation will explain how the WHIMex team was able to propose an x-ray spectrograph with up to 500 square centimeters of collecting area and spectral resolution of 4000 within the size and cost constraints of the Explorer program. We will present the design of WHIMex and show how the high collecting area and high resolution can enable detection of OVII and OVIII features along the lines of sight to AGNS's as distant z=0.5 and start to better constrain the models of the WHIM. 221.07 The Warm-Hot Intergalactic Medium Explorer (WHIMex) Mission Concept Charles F. Lillie1, W. C. Cash2, R. L. McEntaffer3, W. Zhang4, S. O'Dell5, M. Bautz6, M. Elvis7 1Northrop Grumman Aerospace Systems, 2University of Colorado, 3University of Iowa, 4NASA/GSFC, 5NASA/MSFC, 6Smithsonian Astrophysical Observatory, 7Massachusetts Institute of Technology. 5:42 PM - 5:54 PM Staffordshire WHIMEx is a low-cost, highly capable, single instrument X-ray observatory proposed as a NASA Explorer 2011 mission. WHIMEx will use high resolution X-ray spectroscopy (R ≥ 4000) to probe the hot, tenuous gas that populates the great stretches between the galaxies - the place where most of the baryons in the Universe reside. The bulk of this gas is so hot that it can only be studied in the soft X-ray region where the atomic diagnostics for highly ionized species reside. And this gas is so tenuous that it can only be observed in absorption. To detect the absorption lines of O VII and O VIII along the line of sight to distant AGN requires an order of magnitude improvement in both spectral resolution and collecting area over the current best X-ray spectrographs on Chandra and XMM-Newton. WHIMEx achieves this goal in a compact and affordable package through the application of technologies that were developed over the last decade for the International X-ray Observatory. WHIMex uses ultra-thin, light, densely nested parabolic-hyperbolic mirror pairs to create a telescope with a high collecting area and 15 arcsecond resolution. The X-ray beam is dispersed in wavelength by an array of radial gratings in the extreme off-plane mount. Spectral resolving power of 4000 (λ/δλ) is expected in the 0.15 to 2keV band to bring weak absorption lines out of the noise. A collecting area up to 360 cm2 will enable spectral observations of high red shift AGNs.If selected WHIMEx could be launched in mid- 2017 on a Taurus or Athena II from Vandenberg AFB into its 540 km, 70° inclination low earth orbit. In flight, it would open up a new field of exploration with high resolution observations of AGN outflows, the IGM, interstellar medium, mass transfer binaries, stellar coronae and much more 222 Sustainability and Astronomy: "Green" Professional Action and Public Outreach Special Session St. George AB Tuesday, May 24, 2011, 7:00 PM - 8:00 PM 223 SPD Hale Prize: The Sun's Magnetic Surface Invited Session America South |223.01 The Sun's Magnetic Surface Hendrik Spruit1 1MPI for Astrophysics, Germany. 7:00 PM - 8:00 PM America South An overview is given of the history and present status of observations and theory of magnetic fields as observed at the solar surface: their structure, their evolution, and their effect on the Sun's brightness. By a fortunate coincidence, the photosphere is the region most accessible to direct numerical MHD simulations. The spectacular level of qualitative and quantitative realism now possible is illustrated by comparisons with the equally remarkable advances high-resolution observations achieved in recents years. These comparisons are now yielding confident physical interpretations of many of the observed properties of the Sun's surface magnetic fields, including, for example the bewildering detail of sunspot structure. The controversial question of a possible connection between climate and brightness variations over the Sun's magnetic cycle will be discussed in the light of recent observational and numerical results. Wednesday Wednesday, May 25, 2011, 8:00 AM - 7:00 PM 322 Variable Stars Poster Session Essex Ballroom 322.01 Hα Monitoring of Early-Type Emission Line Stars Steven P. Souza1, E. Boettcher2, S. Wilson1, M. Hosek1 1Williams College, 2Haverford College. 8:00 AM - 7:00 PM Essex Ballroom We have begun a narrowband imaging program to monitor Hα emission in early-type stars in young open clusters and associations. A minority of early-type stars, particularly Be stars, show Hα in emission due to extended atmospheres and non-equilibrium conditions. Emission features commonly vary irregularly over a range of timescales (Porter, J.M. & Rivinus, T., P.A.S.P. 115:1153-1170, 2003). Some of the brightest such stars, e.g. γ Cas, have been spectroscopically monitored for Hα variability to help constrain models of the unstable disk, but there is relatively little ongoing monitoring in samples including fainter stars (Peters, G., Be Star Newsletter 39:3, 2009). Our program uses matched 5nm-wide on-band (656nm) and off-band (645nm) filters, in conjunction with the Hopkins Observatory 0.6-m telescope and CCD camera. Aperture photometry is done on all early-type stars in each frame, and results expressed as on-band to off-band ratios. Though wavelength-dependent information is lost compared with spectroscopy, imaging allows us to observe much fainter (and therefore many more) objects. Observing young clusters, rather than individual target stars, allows us to record multiple known and candidate emission line stars per frame, and provides multiple "normal" reference stars of similar spectral type. Observations began in the summer of 2010. This project has the potential to produce significant amounts of raw data, so a semi-automated data reduction process has been developed, including astrometric and photometric tasks. Early results, including some preliminary light curves and recovery of known Be stars at least as faint as R=13.9, are presented. We gratefully acknowledge support for student research through an REU grant to the Keck Northeast Astronomy Consortium from the National Science Foundation, and from the Division III Research Funding Committee of Williams College. 322.02 Many Flares Make a Corona Steven H. Saar1, V. Kashyap1, J. Drake1, K. Reeves1, A. Connors2 1Harvard-Smithsonian, CfA, 2Eureka Scientific. 8:00 AM - 7:00 PM Essex Ballroom It is well known that solar flare energies have a self-similar distribution. The number of flares, N, of any given energy, E, follows a power-law distribution, dN/dE ~ E^(-alpha), over many orders of magnitude, with alpha ~ 1.8. A similar distribution holds for stellar coronae, but in this case, typically alpha > 2. The value alpha=2 is important because it represents a threshold beyond which it is possible to ascribe all of the coronal luminosity to increasingly weaker, but more numerous, flares. Current methods to evaluate the flare distribution index alpha for stars are limited by two factors: they either depend on explicit detections of flares, or if the flare distribution itself is being modeled, then they are highly computation intensive and are thus slow. We have developed analytical methodology that substitutes for Monte Carlo simulations over a majority of the latter calculations. This causes improvements in computational speed of over 100x. We describe these methods below, and apply it to some simulated and observed data. This work was supported by CXC NASA contract NAS8-39073 and Chandra grant AR0-11001X. 322.03 Variable Stars in the 3.6 Year DIRBE Near-Infrared Light Curve Archive Kathleen E. Kraemer1, S. D. Price1, B. J. Smith2, T. A. Kuchar3, D. R. Mizuno3, J. Webb2 1Air Force Research Lab, 2East Tennessee State University, 3Boston College. 8:00 AM - 7:00 PM Essex Ballroom The 3.6 year light curve archive created by Price et al. (2010) from the cryo+post-cryo Diffuse Infrared Background Experiment (DIRBE) mission contains a wealth of variable star information at 1.25, 2.2, 3.5, and 4.9 microns. Of the ~2700 objects in the archive, over 500 show strong variability and another 75 show potential variability. We have combined visible observations obtained during the DIRBE extended mission with the infrared archive to investigate wavelength-dependent phase lags between the visible and the near-IR maxima, extending the study of Smith et al. (2006) to those stars with periods longer than the ~300 day cryo mission. Of those 518 stars exhibiting strong near-infrared variability, ~200 have visible light curves in the American Association of Variable Star Observers database during the DIRBE mission. Because viewing geometry for both the visible observers and DIRBE mission limited the opportunities for observing the stars, the light curves were inspected to determine if the peaks were defined well enough to determine phase lags among the five wavebands. For those objects that have sufficient data, we investigate a number of methods to best estimate the peaks and thus find the phase lags, if any. We have also examined the differences in phase dependence on variable type, e.g. Miras, SRa's, SRb's, and carbon stars. The DIRBE light curve data are available to the community through the Vizier service at the Centre de Donnees Astronomique de Strasbourg. 322.04 Analyzing Dust Spectra Of Oxygen-rich Agb Stars Using Spatially Resolved Spectroscopy. Suklima Guha Niyogi1, A. K. Speck1, K. Volk2 1University of Missouri, 2Space Telescope Science Institute. 8:00 AM - 7:00 PM Essex Ballroom We present Gemini/ Michelle observational data of 7 oxygen-rich asymptotic giant branch (AGB) stars. Using spatially resolved spectroscopy, we investigate the changes in infrared (IR) spectral dust features with radial distance from the central star. We compare the results to those expected from the hypothetical dust condensation sequence, stellar pulsation and dust formation. In particular, the spatially resolved spectral features allow us to determine which features are correlated and help us to determine the true dust carrier(s) of observed spectral features around O-rich AGB stars. 322.05 Red-Eye Astronomy: 15 Years of V-band and Near-IR Tio Photometry of the Red Supergiants Alpha Orionis And TV Geminorum. Richard P. Wasatonic1, E. Guinan1, S. Engle1 1Villanova Univ.. 8:00 AM - 7:00 PM Essex Ballroom V-band and narrow to intermediate-band Wing TiO-band (719 nm, 754 nm), and near-IR 1024 nm pseudo-bolometric photometric observations of the SRc M2 Iab supergiants Alpha Orionis and TV Geminorum have been conducted for the past 15 years. The goals are to monitor brightness and temperature-dependent TiO-band variations, ascertain any resulting periodicities and amplitudes, and estimate variations of basic stellar parameters such as temperature, luminosity, and radius. Preliminary results for both stars indicate similar long-term V-mag periods of ~6.5 years with imposed shorter-term V-mag periods of ~1.2 years. The V-magnitude amplitudes were 0.8 for Alpha Ori and 1.3 for TV Gem. For both stars the temperature and luminosity variations correlate well with the V-mag changes. However, inverse radii correlations with respect to temperature and luminosity variations were not seen in either star. In Alpha Ori the the radii changes were approximately in direct correlation with the temperature and luminosity changes. In TV Gem there was a combination of correlation/inverse correlation effects. Causes for these variations are speculative, but may be due to highly convective super-granulations occurring at irregular intervals rather than fundamental mode pulsation or harmonic oscillations. Based in part on an updated RSG temperature scale and a new VLA/Hipparchos distance estimate (197 PC), the Alpha Ori temperatures ranged from 3550 K to 3730 K, with ranges in solar luminosities and radii of L = 90,000 to 115,000 and R = 760 to 820, respectively. The slightly more dynamical TV Gem underwent temperature variations from 3500 K to 3850 K with ranges in solar luminosity and radii of L = 65,000 to 90,000 and R = 620 to 720 respectively. Discussions of the observations, data reduction methods, and analysis of the data will be presented. This research is supported by NASA grant NNX10AI85G and NSF grants AST 10-09903 and AST 05-07542. 322.06 New Evidence for Mass-Loss from δ Cephei Based on HI 21-cm Line Observations Lynn D. Matthews1, M. Marengo2, N. R. Evans3 1MIT Haystack Observatory, 2Iowa State University, 3Harvard-Smithsonian Center for Astrophysics. 8:00 AM - 7:00 PM Essex Ballroom Our recent Spitzer Space Telescope observations of the classical Cepheid archetype δ Cep revealed an extended (~21,000 AU) dusty nebula surrounding this star and its hot companion HD213307 (Marengo et al. 2010, ApJ, 725, 2392). At far infrared wavelengths, the emission resembles a bow shock aligned with the direction of space motion of the star. These observations strongly suggest that δ Cep is currently undergoing mass-loss through a stellar wind. To further investigate the nature of this probable mass-loss, we have used the Very Large Array (VLA) to search for 21-cm emission from neutral atomic hydrogen that may originate directly in the stellar wind and/or be swept up from the interstellar medium. Our VLA data reveal a spatially extended nebula of atomic hydrogen 10' (~0.8 pc) across surrounding the position of δ Cep. Although a portion of the HI line profile is strongly contaminated by Galactic emission along the line-of-sight, the emission detected within the uncontaminated portion of our band is consistent with circumstellar material originating in an optically thin wind with an outflow velocity of ~40 km/s. A portion of the detected HI emission also appears to be swept into a wake trailing the star's space motion. We will discuss the implications of these observations for Cepheid evolution and for resolving the so-called "Cepheid mass discrepancy". This work is supported by grant AST-1009644 from the National Science Foundation. 322.07 A Phase Shift in the Light Curve of Cepheid Variable CF Cas Timothy M. Taber1, F. R. Chromey1 1Vassar College. 8:00 AM - 7:00 PM Essex Ballroom We present CCD photometry in the V and R bands for the Cepheid variable CF Cassiopeiae over three observing seasons, 2008-2010. The light curve shows a phase shift of 0.07 (8.2 hours) compared to values based on the cataloged epoch and period. Our data do not support a change in the period from the catalog value of 4.87522 days. 322.08 Securing the Distance Scale via a Universal VI Wesenheit Template and Deep Infrared ZAMS Daniel Majaess1, D. Turner1, D. Lane1 1Saint Mary's University, Canada. 8:00 AM - 7:00 PM Essex Ballroom HST, VLBA, and HIP geometric distances to SX Phe, Delta Scuti, RR Lyrae, Type II and classical Cepheid variables are used to construct a universal VI Wesenheit template. The template uses the statistical weight of the entire variable star demographic to establish precise (<5%) distances to nearby galaxies, star clusters, etc. The reddening-free nature of the Wesenheit approach obviates the propagation of uncertainties tied to tentative total/differential extinction corrections, ensuring that further calibration may ensue directly from published or forthcoming geometric-based distances (masers, HST, GAIA, SIM). An empirical JHKs ZAMS established from deep 2MASS photometry and precise HIP parallaxes for nearby stars provides a concurrent means of securing absolute Wesenheit magnitudes for variables in stellar clusters (calibrators). The infrared ZAMS is comparatively insensitive to stellar age and [Fe/H], and yields distances to 7 of 9 benchmark open clusters that agree with the van Leeuwen (2009) revised HIP estimates (the Pleiades and Blanco 1 are discrepant cases, but should not detract from the broader consensus). In sum, the distance scale is secured to a geometrically anchored framework that consists of results from several key surveys (OGLE, NOMAD, ASAS, etc.) united by a universal VI Wesenheit template and deep infrared ZAMS. Future research entails populating the universal Wesenheit template with lower-temperature calibrators (variable red giants, Miras, longer period Cepheids, etc.) using observations acquired from the ARO, SRO (AAVSO), OMM, and DAO, and further characterizing insidious photometric contamination associated with variables occupying crowded regions near the cores of globular clusters and galaxies (including the Milky Way). 322.09 The Connection Between SX Phe and Blue Stragglers: Globular Cluster Variables as Period-Luminosity Relation Calibrators Roger Cohen1, A. Sarajedini1 1Univ. Of Florida. 8:00 AM - 7:00 PM Essex Ballroom The number of known SX Phoenicis (SX Phe) pulsators in Galactic globular clusters (GGCs) and the Local Group has more than doubled in recent years. Because all SX Phe in GGCs are likely blue stragglers, it has been suggested that their pulsational properties can constrain their evolutionary histories. We investigate the connection between SX Phe and blue stragglers via period-luminosity and color-magnitude diagrams. In particular, we verify distances to a large set of GGCs by fitting a carefully chosen set of nearby, unevolved subdwarfs to the cluster main sequences. We use these distances to analyze the pulsational properties of all known SX Phe, including SX Phe period-luminosity relations obtained using the SX Phe in these GGCs as calibrators, together with those in Local Group dwarf galaxies and their clusters. Finally, we discuss implications for blue straggler formation and evolution, and address both observational and theoretical avenues for further investigation. 323 Stellar Atmospheres, Winds Poster Session Essex Ballroom 323.01 Theoretical Near-IR Spectra for Surface Abundance Studies of Massive Stars George Sonneborn1, J. Bouret1 1NASA's GSFC. 8:00 AM - 7:00 PM Essex Ballroom We present initial results of a study of abundance and mass loss properties of O-type stars based on theoretical near-IR spectra computed with state-of-the-art stellar atmosphere models. The James Webb Space Telescope (JWST) will be a powerful tool to obtain high signal-to-noise ratio near-IR (1-5 micron) spectra of massive stars in different environments of local galaxies. Our goal is to analyze model near-IR spectra corresponding to those expected from NIRspec on JWST in order to map the wind properties and surface composition across the parameter range of O stars and to determine projected rotational velocities. As a massive star evolves, internal coupling, related mixing, and mass loss impact its intrinsic rotation rate. These three parameters form an intricate loop, where enhanced rotation leads to more mixing which in turn changes the mass loss rate, the latter thus affecting the rotation rate. Since the effects of rotation are expected to be much more pronounced at low metallicity, we pay special attention to models for massive stars in the the Small Magellanic Cloud. This galaxy provides a unique opportunity to probe stellar evolution, and the feedback of massive stars on galactic evolution in conditions similar to the epoch of maximal star formation. 323.02 A Detailed Spectral Analysis of the Sharp-lined B3 IV Star Iota Herculis Saul J. Adelman1, A. Farr1, A. Gulliver2, G. Hill3, G. Peters4, K. Yuce5 1The Citadel, 2Brandon University, Canada, 3Retired, New Zealand, 4University of Southern California, 5Ankara University, Turkey. 8:00 AM - 7:00 PM Essex Ballroom We derived the elemental abundances of the sharp-lined B3IV star iota Herculis from high quality optical region spectra (Δλ/λ = 67000, signal-to-noise ≥ 750) obtained with the long camera of the coude spectrograph of the 1.22-m telescope of the Dominion Astrophysical Observatory, Victoria, BC. Canada. The 4096 pixel long SITe4 CCD was used. Generally, two or three one-hour spectra of the same region taken on the same night were co-added to increase the S/N. Twenty-one central wavelength settings covered the entire spectrum (λλ3827-8976) where the desired S/N could be obtained. The regions selected were not seriously affected by telluric lines were not observed. The spectrum was measured using the REDUCE family of programs of Graham Hill. H I, He I, C II, C III, N I, N II, O I, O II, Ne I, Mg II, Al II, Al III, Si II, Si III, P II, P III, S II, S III, Ar II, Fe II, Fe III, and Ni II lines are used to derive the elemental abundances in an LTE fine analysis using Kurucz’s ATLAS9 and WIDTH9 programs. Lines of additional species might be present. Initial estimates of the effective temperature, surface gravity, and microturbulence are 17400 K, 3.85 dex, and 1.9 km s-1, respectively. The He/H ratio is found to be near solar as are the other derived abundances. However, abundances of the same element derived from two species can be different. This probably indicates that some adjustments of these parameters and non-LTE physics are needed to get ionization equilibrium. In addition to our fine analysis we performed a synthesized spectra analysis to refine the results. SJA and AFG are Guest Observers at the Dominion Astrophysical Observatory. 323.03 Surface Abundance Patterns in A-Type Stars from UV Spectral Synthesis Edward L. Fitzpatrick1 1Villanova University. 8:00 AM - 7:00 PM Essex Ballroom In this poster, we present results from a program whose goals are to (1) examine the degree to which current LTE atmosphere models can reproduce the complex UV spectra (1200-3200 A) of the A-type stars; in order to (2) develop better estimates of the physical properties, including composition, for specific target stars with available archival UV data; and (3) examine the abundance patterns revealed from a large group of normal and peculiar A-type stars to gain insight into the processes driving the compositional anomalies often observed in this spectral domain. We use the ATLAS9 atmospheric structure models from R.L. Kurucz, the spectral synthesis program SPECTRUM from R. Gray, and a new atomic line list developed from data in the VALD and NIST archives. For most of the stars, the data are high-dispersion spectrophotometry from the IUE satellite, although in several cases very high quality HST spectroscopy from GHRS and STIS are available. In addition to measurements of effective temperature, surface gravity, mictrotubulence velocity, and rotational velocity, we are also able to determine abundances for over 30 elements per star, including CNO, the light metals, the Fe group, and a number of heavy elements. We illustrate the striking abundance patterns for a number of stars, including members of the Am and HgMn classes, along with several ``normal’’ and ``superficially normal’’ stars. This research has been supported by NASA Astrophysics Data Program grant NX08AJ62G. 323.04 Line Identifications in the Far Ultraviolet Spectrum of the Eclipsing Binary System 31 Cygni Wendy Hagen Bauer1, P. D. Bennett2 1Wellesley College, 2Eureka Scientific. 8:00 AM - 7:00 PM Essex Ballroom The eclipsing binary system 31 Cygni (K4 Ib + B3 V) was observed at several phases with the Far Ultraviolet Spectrosocopic Explorer (FUSE) satellite. During total eclipse, a rich emission spectrum was observed, produced by scattering of hot star photons in the extended wind of the K supergiant. The system was observed during deep chromospheric eclipse, and ~2.5 months after total eclipse ended. We present an atlas of line identifications in these spectra. During total eclipse, emission features from C II , C III, N I, N II, N III, O I, Si II, P II, P III, S II, S III, Ar I, Cr III, Fe II, Fe III, and Ni II were detected. The strongest emission features arise from N II. These lines appear strongly in absorption during chromospheric eclipse, and even 2.5 months after total eclipse, the absorption bottoms out on the underlying emission seen during total eclipse. The second strongest features in the emission spectrum arise from Fe III. Any chromospheric Fe III absorption is buried within strong chromospheric absorption from other species, mainly Fe II. The emission profiles of most of the doubly-ionized species are red-shifted relative to the systemic velocity, with asymmetric profiles with a steeper long-wavelength edge. Emission profiles from singly-ionized species tend to be more symmetric and centered near the systemic velocity. In deep chromospheric eclipse, absorption features are seen from neutral and singly-ionized species, arising from lower levels up to ~3 eV. Many strong chromospheric features are doubled in the observation obtained during egress from eclipse. The 31 Cygni spectrum taken 2.5 months after total eclipse ended ws compared to single-star B spectra from the FUSE archives. There was still some additional chromospheric absorption from strong low-excitation Fe II, O I and Ar I. 323.05 Comparing High-Precision Stellar Diameters From the Navy Prototype Optical Interferometer With Stellar Atmosphere Models as a Function of Wavelength Anders M. Jorgensen1, J. T. Armstrong2, H. R. Schmitt2, E. K. Baines2, D. Mozurkewich3, C. Tycner4, D. J. Hutter5, T. Hall1, D. Paiton1, M. Brown1, B. Curtis1 1New Mexico Tech, 2Naval Research Laboratory, 3Seabrook Engineering, 4Central Michigan University, 5Naval Observatory Flagstaff Station. 8:00 AM - 7:00 PM Essex Ballroom In this paper we use the coherent integration technique to obtain extremely high precision stellar diameters as a function of wavelength in the visible band using observations from the Navy Prototype Optical Interferometer (NPOI). We then compare these diameters with stellar atmosphere models as a function of wavelength. Coherent integration is a post-processing technique which corrects for atmospheric optical-path-difference shifts in interferometric data and allows, effectively, to increase the integration time of optical interferometric data indefinitely by summing many short exposures suitably phase-shifted. This is significant because coherent integration, which allows the complex visibilities to be summed in phase, greatly improves the signal-to-noise ratio over traditional techniques which average squared visibilities. The improvement is particularly dramatic for faint targets, and/or when the visibility amplitude is very small. This is important when measuring stellar diameters on resolving baselines that include visibility nulls. Those baselines best constrain the diameters. However in order to take full advantage of the null as a diameter measure it is necessary to obtain high-SNR measurements around the null, which is possible with coherent integration. We present wavelength-dependent uniform disk diameter measurements with precision up to 1:500 to 1:1000. We then compare these with the corresponding uniform-disk diameters obtained from stellar atmosphere models 323.06 Diameters and Temperatures of Main-Sequence Stars Tabetha S. Boyajian1, H. McAlister1, K. von Braun2, G. van Belle3, D. Gies1, T. ten Brummelaar1, C. Farrington1, P. Goldfinger1, S. Ridgway4, L. Sturmann1, J. Sturmann1, G. Schaefer1, N. Turner1 1Georgia State UNIV./CHARA, 2NExScI/Caltech, 3ESO, Germany, 4NOAO. 8:00 AM - 7:00 PM Essex Ballroom We present the current status of the survey to measure accurate diameters of nearby, main-sequence stars with the CHARA Array, a long baseline optical/infrared interferometer. This project is the source of the largest homogeneous data set that provides direct measurements of the stellar linear radius and effective temperature for stars of this type. We discuss the challenges these data bring to current stellar atmospheric and evolutionary models, as well as the development of empirically based relations and calibrations to the stellar effective temperature scale. 324 SPICA Poster Session Essex Ballroom 324.01 Is Space-based Interferometry Dead? David Leisawitz1, D. Benford1, A. Blain2, J. Carr3, M. Fich4, J. Fischer3, P. Goldsmith5, J. Greaves6, M. Griffin7, G. Helou8, R. Ivison9, M. Kuchner1, R. Lyon1, H. Matsuo10, S. A. Rinehart1, E. Serabyn5, H. Shibai11, R. Silverberg1, J. Staguhn12, S. Unwin5, D. Wilner13, A. Wootten14, E. L. Wright15 1NASA GSFC, 2Univ. Leicester, United Kingdom, 3NRL, 4Univ. Waterloo, Canada, 5Caltech JPL, 6Univ. St. Andrews, United Kingdom, 7Cardiff Univ., United Kingdom, 8Caltech IPAC, 9UK ATC, United Kingdom, 10NAOJ, Japan, 11Nagoya Univ., Japan, 12JHU/NASA GSFC, 13CfA, 14NRAO, 15UCLA. 8:00 AM - 7:00 PM Essex Ballroom In the wake of the Decadal Survey and a January 2011 meeting of NASA’s Exoplanet Exploration Program Analysis Group (ExoPAG), one might be tempted to conclude that space interferometry is dead. We explain why this slogan is hyperbole, summarize the steps currently being taken to prepare for a space-based far-IR interferometer, and reiterate the science case for an imaging and spectroscopic interferometer - SPIRIT - that would operate in space at long infrared wavelengths. Space-based interferometry is alive and well, but the center of activity has shifted to a spectral region (25 to 400 microns) in which no alternative measurement technique can provide information essential to answering several scientific questions deemed compelling by the Decadal Survey. Astrophysicists will use SPIRIT to: discover how the conditions for habitability arise during planetary system formation; find and characterize exoplanets by measuring their sculpting effects on protoplanetary and debris disks; and study the formation, merger history, and star formation history of galaxies. 324.02 Designing the Balloon Experimental Twin Telescope for Infrared Interferometry Stephen Rinehart1, R. Barry2, D. Benford1, W. Danchi2, D. Fixsen3, C. Jhabvala4, D. Leisawitz5, L. Mundy6, R. Silverberg1, J. Staguhn7 1NASA's GSFC Code 665, 2NASA's GSFC Code 667, 3University of Maryland, College Park, 4NASA's GSFC Code 553, 5NASA's GSFC Code 605, 6University of Maryland College Park, 7Johns Hopkins University. 8:00 AM - 7:00 PM Essex Ballroom While infrared astronomy has revolutionized our understanding of galaxies, stars, and planets, further progress on major questions is stymied by the inescapable fact that the spatial resolution of single-aperture telescopes degrades at long wavelengths. The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter boom interferometer to operate in the FIR (30-90 μm) on a high altitude balloon. The long baseline will provide unprecedented angular resolution (~0.5[[Unsupported Character - ˝]]) in this band. In order for BETTII to be successful, the gondola must be designed carefully to provide a high level of stability with optics designed to send a collimated beam into the cryogenic instrument. We present results from the first 5 months of design effort for BETTII. Over this short period of time, we have made significant progress and are on track to complete the design of BETTII during this year. 324.03 How WISE Points to Future Far-Infrared Missions Dominic J. Benford1, D. T. Leisawitz1, E. L. Wright2 1NASA / GSFC, 2UCLA. 8:00 AM - 7:00 PM Essex Ballroom Based on the tantalizing science that is emerging from the first WISE discoveries, we consider the impact that the future will bring to far-infrared mission concepts. What we've learned from WISE gives us new investigations for missions like SPICA and SPIRIT. We highlight the new results from WISE and incorporate that into the context of the Far-Infrared Community Plan and the recent New Worlds, New Horizons documents. 324.04 Understanding The Heating And Cooling Of Galaxies Over Cosmic Time With BLISS on SPICA Lee Armus1, G. Helou2, M. Bradford3, E. Murphy4, P. Appleton5 1Spitzer Science Center/Caltech, 2IPAC/Caltech, 3JPL/Caltech, 4Observatories of the Carnegie Institution for Science, 5NASA Herschel Science Center/Caltech. 8:00 AM - 7:00 PM Essex Ballroom In order to gain a comprehensive picture of galaxy evolution, we need to accurately measure the growing population of stars and super-massive black holes in dark matter halos. The processes that regulate this evolution are invariably those that are the most difficult to simulate, namely gas heating and cooling, star formation, black hole fueling and feedback from supernovae and AGN. Measurements of the PAH features, atomic fine-structure and H2 lines in the mid-infrared with Spitzer have been used successfully to probe the dust properties, power sources and state of the ISM in normal, starburst and AGN host galaxies at 0 < z < 3. At high redshifts, these lines enter the far-infrared, which is also home to critical diagnostics of the neutral and ionized ISM, such as [OI], [OIII], [NII], and [CII]. Recent results from Herschel, CSO, IRAM and APEX suggest that there is an extremely large range in far-infrared line fluxes and physical conditions among the most luminous, high-z galaxies. However, to measure the rest-frame far-infrared cooling lines in galaxies that dominate the far-infrared background, along with the full suite of mid-infrared atomic and molecular gas and dust features in ULIRGs over a wide range in redshift, a broadband spectrometer capable of reaching the natural astrophysical background over the 30-400 micron range is required. The Background Limited Infrared Sub-millimeter Spectrometer (BLISS) on the Japanese-led SPICA mission, would deliver unmatched sensitivity to evolving, dusty galaxies over all epochs. Here we discuss the scientific rationale behind BLISS and the opportunities afforded by US participation in the SPICA mission. 324.05 The Background-Limited Infrared Submillimeter Spectrograph (BLISS) for SPICA Charles Bradford1, BLISS-SPICA Study Team 1Caltech/ JPL. 8:00 AM - 7:00 PM Essex Ballroom The far-IR waveband carries half of the photon energy ever produced in galaxies and quasars, evidence of the major role of dust-obscured star formation and black-hole growth had in bringing about the modern Universe. The bulk of this dust-obscured activity appears to have occurred in the first half of the Universe's history (z>1). We are developing the Background-Limited Infrared-Submillimeter Spectrograph (BLISS) to capitalize on SPICA's cold telescope and provide a breakthrough far-IR spectroscopy capability. BLISS-SPICA is 6 orders of magnitude faster than the spectrometers on Herschel and SOFIA in obtaining full-band spectra, and offer the capability to overcome the spatial confusion limit with spectroscopic capability. BLISS-SPICA will observe dust-obscured galaxies at all epochs back to the first billion years after the Big Bang (redshift 6), thereby probing the complete history of dust-obscured star formation and black-hole growth. It will also be extremely powerful for studying ice-giant planet formation in protoplanetary disks, with its sensitivity to very small amounts of gas. Given its enormous potential, BLISS has been recommended by Astro2010 as an example US contribution to SPICA. BLISS covers the 38-433 micron range in six grating-spectrometer bands, with two simultaneous sky positions. The baseline detector package is 4224 silicon-nitride micro-mesh leg-isolated bolometers with superconducting transition-edge-sensed (TES) thermistors, read out with a cryogenic time-domain multiplexer. All spectrometers and detector arrays are cooled to 50mK for optimal sensitivity. All technical elements of BLISS have heritage in mature scientific instruments, and many have flown. We present the science case for BLISS, as well as our progress in the key technical aspects: 1) detector and readout performance demonstration, 2) opto-mechanical instrument configuration, and 3) sub-K cooling and cryogenic system approach. 324.06 The Molecular Hydrogen Discovery Potential of SPICA/BLISS Philip N. Appleton1, L. Armus1, G. Helou1, C. M. Bradford2, E. Murphy1 1Caltech, 2JPL. 8:00 AM - 7:00 PM Essex Ballroom The BLISS spectrometer concept for the Space Infrared Telescope for Cosmology and Astrophysics (SPICA) observatory is an ideal instrument to search for powerful H2 line-emission at redshifts 2 < z < 5: the likely epoch at which massive galaxies are transformed from gas into stars. Unlike some other molecular tracers, the pure rotational transitions of molecular hydrogen at high redshift can only be studied in the far-IR, and direct measurements of H2 is out of reach of ALMA for redshifts less than z = 15. The IR H2 lines have proved to be surprisingly strong in low-redshift shock-driven systems, even in the presence of other metal cooling channels. However, little is yet know about the importance of shock-driven H2-line cooling at high-redshift in more pristine, metal-poor environments. We will show that the proposed SPICA/BLISS combination will provide a unique opportunity to probe into the sensitivity range expected for excited molecular hydrogen from galaxies up to at least z = 5. The study of the dissipation of kinetic energy through turbulence, strongly suspected as the main power-source in the local H2-bright systems, is likely to be of major importance in galaxy building. By analogy with these local H2-bright systems, SPICA/BLISS has the sensitivity to allow us to exploit this powerful shock-diagnostic for studying the most turbulent regions within forming galaxies. 325 Low-Mass Stellar Science Poster Session Essex Ballroom 325.01 Using Stellar Spectra to Constrain the Distribution of Galactic Dust David Jones1, A. A. West1, J. B. Foster1 1Boston University. 8:00 AM - 7:00 PM Essex Ballroom We use stellar spectra from the Sloan Digital Sky Survey (SDSS) to create a high- latitude extinction map of the local Galaxy. Our technique compares spectra from SDSS stars in low-extinction lines of sight, as determined by Schlegel, Finkbeiner, & Davis, to other SDSS spectra in order to derive improved distance estimates and accurate line-of-sight extinctions. Unlike most previous studies, which have used a two-color method to determine extinction, we fit extinction curves to fluxes across a large spectral range. We apply this method to SDSS K dwarfs, nearby L dwarfs, and stars in the DR7 M dwarf sample. Our result is an extinction map that extends from tens of pc to several kpc away from the sun. We also use a similar technique to create a map of RV values within approximately 1 kpc of the sun, and find they are consistent with the widely accepted diffuse interstellar medium value of 3.1. Using our extinction data, we derive a dust scale height for the local galaxy of 119 ± 15 parsecs and find evidence for a local dust cavity. 325.02 Light Curves, Energetics and Rates of M Dwarf Flares Eric J. Hilton1, S. L. Hawley1, A. F. Kowalski1, S. J. Schmidt1, J. R. A. Davenport1, J. P. Wisniewski1, K. J. Bell1, B. Tofflemire1, J. Holtzman2 1Univ. Of Washington, 2New Mexico State University. 8:00 AM - 7:00 PM Essex Ballroom The magnetic reconnection events that power stellar flares lead to a wide variety of light curve shapes, hinting at the complex underlying magnetic field topologies. Using our quantitative definition of a flare event, we find more than 100 flares during 600 hours of photometric monitoring of two dozen stars. The sample includes both active and inactive M dwarfs with a range of spectral type. We fit models for the light curve evolution to our photometric flare catalogue and present an analysis of the rise and decay times as well as flare colors. We additionally present the distribution of flare rates as a function of energy and equivalent duration. The flare frequency distribution is used to characterize the impact of M dwarf flares seen in time domain surveys, and is also necessary to model the effect of flares on the atmospheres of exoplanets orbiting an M dwarf host. 325.03 The Living with a Red Dwarf Program: dM Star Evolution and the Usefulness of Rotation as an Age Indicator Scott G. Engle1, E. Guinan1, S. Kafka2, S. Messina3, T. Oswalt4, J. Bochanski5 1Villanova University, 2Carnegie Institution - DTM, 3INAF-Catania Astrophysical Observatory, Italy, 4Florida Institute of Technology, 5The Pennsylvania State University. 8:00 AM - 7:00 PM Essex Ballroom The ability to accurately estimate the age of a dM stars is of critical importance. However, due to their long lifetimes, and very slow nuclear evolution, the best method for determining ages would seem to be through “magnetic tracers” such as X-UV activity levels and stellar rotation rates. The Living with a Red Dwarf Program’s database of dM stars with photometrically determined rotation rates (from starspot modulations) is becoming substantial, and has recently been expanded to include dM stars with well-detached WD companions - through which reliable ages can be determined. When combined with dM stars possessing cluster/population memberships, or specific kinematics, a full range of Main Sequence ages is being realized. We report on our continuing efforts to build reliable Age-Activity-Rotation relationships for dM stars. Such relationships have broad impacts on not only the studies of Magnetic Dynamo Theory and Angular Momentum Loss on low-mass stars with deep convective zones, but also the suitability of planets around red dwarfs to sustain life. We hope that, after proper calibration, the relationships will also permit the age of a field red dwarf to be determined through measures of either its rotation period or X-UV activity level. 325.04 Activity in M Dwarf Members of NGC 2516 and M67: Calibrating an Age-Activity Relation Jan M. Andersen1, A. A. West1, K. R. Covey2, M. McDonald3, S. Veilleux3, A. Seth4 1Boston University, 2Cornell University, 3University of Maryland, 4Harvard-Smithsonian Center for Astrophysics. 8:00 AM - 7:00 PM Essex Ballroom We present preliminary results from a study of M dwarf magnetic activity in clusters of known ages with the ultimate goal of constraining the age-activity relation. The age-activity relation provides clues to the mechanisms generating magnetic dynamos, especially in late-type dwarfs where their stellar interiors become fully convective. Broadband griz photometry was obtained for four clusters with ages ranging from 150 Myrs to 4 Gyrs. Narrowband images of each cluster were acquired with the Maryland Magellan Tunable Filter, tuned to the frequency of H-alpha (including a correction for each cluster’s radial velocity) and a nearby, similarly sized bandpass sampling the stellar pseudo-continuum. This permits a “photometric” measurement of the H-alpha emission for each star, and thus a measure of activity. Cluster membership is determined from broadband photometry and comparison to stellar positions from previous studies. We report on our findings for the clusters NGC 2516 and M67. H-alpha measurements are stronger for cluster stars than for field stars of the same magnitude. In NGC 2516, a clear correlation is seen between our H-alpha strengths measured by narrowband imaging and previous spectroscopic activity measurements in stars for which spectra have been obtained. J.M.A. acknowledges support through an NSF Graduate Research Fellowship. 325.05 FIRE Echelle Spectroscopy of T Dwarfs: Speeds and Spins of the Coldest Brown Dwarfs Adam J. Burgasser1, J. J. Bochanski2, R. A. Simcoe3, J. K. Faherty4 1UC San Diego, 2Pennsylvania State University, 3MIT, 4American Museum of Natural History. 8:00 AM - 7:00 PM Essex Ballroom The Folded-port Infrared Echellette (FIRE) spectrograph has recently been commissioned on 6.5m Baade Telescope, enabling high-throughput, low- and moderate-resolution spectroscopy of faint infrared sources. As part of science verification observations, we have observed a sample of ~35 mid- and late-type T dwarfs in the southern hemisphere down to J ~ 17 at a resolution of 6000 (Δv = 50 km/s), spanning the full 0.85-2.4 micron near-infrared window. We present the results of these observations, including radial velocity measurements based on both spectral fitting and comparison to radial velocity standards, and 3D kinematics for sources with proper motions and parallaxes from the Brown Dwarf Kinematics Program. We also present preliminary rotational velocities down to the pixel-sampling limit (12.5 km/s), made possible by the dozens of molecular transitions resolved by FIRE echelle data. Finally, we present limits on radial velocity variability for two sources suspected of being unresolved (a < 10 AU) spectral binaries. 326 M Dwarfs, Brown Dwarfs, White Dwarfs Poster Session Essex Ballroom 326.01 A Smarts Distance Runner: The 0.9m At Ctio Jennifer G. Winters1, T. Henry2, W. Jao1, J. Subasavage3, C. Finch4, N. Hambly5 1RECONS/Georgia State University, 2RECONS, 3Cerro Tololo Inter-American Observatory, Chile, 4US Naval Observatory, 5SUPA/University of Edinburgh, United Kingdom. 8:00 AM - 7:00 PM Essex Ballroom Determining distances to celestial objects is one of the fundamental challenges in astronomy. In particular, distance determinations to nearby objects are of vital importance, as our solar neighbors set the standard for the primary rung in the cosmic distance ladder. The optimal tool for accomplishing this seemingly simple task is trigonometric parallax. However, because measuring parallaxes is time-intensive, photometric distance estimates are useful in deciding which targets are good candidates for the limited slots available in traditional parallax programs --- or in the near future, which stars are worthy of special attention. In 1999, RECONS (Research Consortium on Nearby Stars) began gathering VRI photometry using the CTIO 0.9m telescope. Observations continued when SMARTS took over operations in 2003, and the nimble, reliable, 0.9m telescope has evolved into a distance runner of sorts --- running methodically all over the southern sky for 12 years, measuring distances to hundreds of stars. As a result, the 0.9m has moved to the forefront of mapping the solar neighborhood, while revamping the distance scale for red dwarfs, by far the most abundant type of star in the cosmos. Here we present a photometric census of the southern sky using these results, with particular emphasis on the large number of newly discovered red dwarfs within 25 pc. In total, we have collected VRI photometry for ~1400 objects, over a thousand of which are M dwarfs (V-K > 3.0). When we combine our VRI photometry with 2MASS JHK magnitudes, we are able to estimate photometric distances accurate to 15%. The nearest candidates are then added to our astrometry program, which now has in excess of 500 nearby red dwarfs racing toward the parallax finish line. This work has been supported by the National Science Foundation, NASA's Space Interferometry Mission, Georgia State University, and Northern Arizona University. 326.02 New Stars with Mid-Infrared Excesses John Gizis1, N. Troup1 1Univ. Of Delaware. 8:00 AM - 7:00 PM Essex Ballroom We present results of an analysis of public infrared sky surveys including 2MASS and AKARI to identify young, low-mass stars with excesses. The results include new T Tauri stars in young associations and debris disk candidates. We also discuss a search for new very high proper motion stars in the solar neighborhood. 326.03 M Dwarf Photometric Variability In The Optical And NIR James R. A. Davenport1, A. C. Becker1, A. F. Kowalski1, S. L. Hawley1, E. J. Hilton1 1University of Washington. 8:00 AM - 7:00 PM Essex Ballroom We present limits on the observability of stochastic flare events from M dwarfs in SDSS and 2MASS filters. We have studied 30,000 M dwarfs from the SDSS Stripe 82 time-domain catalog, and 4300 M dwarfs from the 2MASS Calibration Scan Point Source Working Database which overlap the SDSS DR7 single-epoch data. M dwarfs are chosen based on their SDSS r,i,z colors. Stripe 82 stars each have 50-100 epochs of data, while 2MASS Calibration stars have 2000-3000. An M dwarf continuum spectral model is used to predict observed flare signatures in each band. From these data we estimate the observed rates and theoretical detection thresholds for flares in eight photometric bands as a function of spectral type. The structure function of the variability for each spectral type bin is also calculated for all eight bands. These rates of flares and photometric variations at longer wavelengths will be important for predicting the impact of M dwarf variability in next-generation instruments such as JWST. 326.04 The First Detection of Time-Variable Infrared Line Emission During M Dwarf Flares Sarah J. Schmidt1, E. J. Hilton1, B. Tofflemire1, J. P. Wisniewski1, A. F. Kowalski1, J. Holtzman2, S. L. Hawley1 1University of Washington, 2New Mexico State University. 8:00 AM - 7:00 PM Essex Ballroom M dwarfs are notorious for their active chromospheres, characterized by quiescent line emission at optical wavelengths in addition to dramatic flare events. These flares have been well-studied at X-ray, radio, UV, and optical wavelengths, but so far there is only one single-epoch detection of high-order Paschen emission lines in a red optical spectrum (Schmidt et al. 2007). In order to investigate infrared line emission during flares, we have conducted a monitoring campaign totaling about 60 hours on 5 active M dwarfs. We have obtained infrared (0.9 to 2.4 micron) spectroscopy using the TripleSpec instrument on the Apache Point Observatory 3.5-m, simultaneous optical/UV photometry on the NMSU 1-m and ARC 0.8-m, and optical spectroscopy on the DAO 1.8-m for one run. During the three brightest flares observed on EV Lac and YZ CMi (> 2 magnitudes in U), we observed emission from Hydrogen Paschen beta, gamma, and delta; Brackett gamma, and Helium 10830A. We characterize the strength and time variation of these lines and investigate the heating needed to produce infrared emission during flares. 326.05 Hα Variability in Active M Dwarf Spectra on Intermediate Timescales Keaton Bell1, E. J. Hilton1, S. L. Hawley1, A. B. Rogel2 1University of Washington, 2Bowling Green State University. 8:00 AM - 7:00 PM Essex Ballroom The strength of Hα emission in magnetically active M dwarfs has been observed to increase on very short (seconds) timescales during flares, and to decrease on very long (millions-billions of years) timescales with stellar aging. We utilize a set of ~13,000 time-resolved active M dwarf spectra taken on several-minute intervals from the Sloan Digital Sky Survey and an independent set of 312 Hydra spectra taken hourly with the WIYN 3.5-meter telescope to study Hα variability on intermediate timescales. With several observations per target, and with many targets observed on multiple nights, we are able to probe variability in the equivalent width measurements of Hα on timescales from minutes to weeks. We will present the variability structure function and discuss it in the context of previous results. 326.06 A Proper-Motion Corrected, Cross-Matched Catalog Of M Dwarfs In SDSS And FIRST Erin Arai1, A. A. West1, N. Thyagarajan2, M. Agüeros2, D. Helfand2 1Boston University, 2Columbia University. 8:00 AM - 7:00 PM Essex Ballroom We present a preliminary analysis of M dwarfs identified in both the Sloan Digital Sky Survey (SDSS) and the Very Large Array's (VLA) Faint Images of the Radio Sky at Twenty-centimeters survey (FIRST). The presence of magnetic fields is often associated with indirect magnetic activity measurements, such as H-alpha or X-ray emission. Radio emission, in contrast, is directly proportional to the magnetic field strength in addition to being another measure of activity. We search for stellar radio emission by cross-matching the SDSS DR7 M dwarf sample with the FIRST catalog. The SDSS data allow us to examine the spectra of our objects and correlate the magnetic activity (H-alpha) with the magnetic field strength (radio emission). Accurate positions and proper motions are important for obtaining a complete list of overlapping targets. Positions in FIRST and SDSS need to be proper motion corrected in order to ensure unique target matches since nearby M dwarfs can have significant proper motions (up to ~ 1'' per year). Some previous studies have neglected the significance of proper motions in identifying overlapping targets between SDSS and FIRST; we correct for some of these previous oversights. In addition the FIRST data were taken in multiple epochs; individual images need to be proper motion corrected before the images can be co-added. Our cross-match catalog puts important constraints on models of magnetic field generation in low-mass stars in addition to the true habitability of attending planets. 326.07 The Effect of Close Companions on the Magnetic Activity of M Dwarfs Dylan Morgan1, A. A. West1, N. M. Silvestri2 1Boston University, 2University of Washington. 8:00 AM - 7:00 PM Essex Ballroom We used close white dwarf and M dwarf (WD+dM) binary systems as a method to understand the effect that close companions have on magnetic field generation in M dwarfs. We used a base sample of 1602 white dwarf - main sequence (WDMS) binaries from Rebassa-Mansergas et al. (2010) to aid in determining a set of color cuts using GALEX, SDSS, 2MASS, and UKIDSS colors. Using the Sloan Digital Sky Survey (SDSS) Data Release 8 (DR8) we constructed a sample of ~1800 WD+dM pairs. We separated the dM and WD from each combined spectrum using an iterative technique that compares the WD and dM components to best-fit templates. Using the absolute height above the Galactic plane as a proxy for age and the Hα emission line as an indicator for magnetic activity, we investigated the age-activity relation for our sample. Our results show that M dwarfs in close binary systems have increased magnetic activity in both magnitude and duration compared to their field counterparts. 326.08 Measuring M Dwarf Metallicities To Inform The MEarth Project Target List Elisabeth Rose Newton1, J. Irwin1, D. Charbonneau1, B. Rojas-Ayala2, Z. Berta1, C. Burke1, J. Dittman1, E. Falco1, P. Nutzman3 1Harvard University, 2Cornell University, 3UC Santa Cruz. 8:00 AM - 7:00 PM Essex Ballroom M dwarfs are the most promising candidates around which to find habitable, Earth-sized planets amenable to detailed spectroscopic study of their atmospheres by transmission or occultation methods. A correlation between stellar metallicity and planet occurrence has been demonstrated for F, G and K stars, with exoplanet detections rising sharply above solar metallicity. Recent results indicate that this relation holds for M-type stars; if correct, we would be able to increase the yield of planet surveys by targeting metal-rich stars. The MEarth Project is a transiting planet survey that is photometrically monitoring 2000 of the nearest M dwarfs in the Northern sky and which will expand in the next year to include an additional 2000 stars in the southern hemisphere. We will present the first results of a campaign to measure the metallicities of M dwarfs in the MEarth sample. We are using and refining a new method for measuring M dwarf metallicities pioneered by Rojas-Ayala et al. (2010) that uses moderate resolution mid-infrared spectra. Unlike other empirical methods for measuring M dwarf metallicities, it does not rely on parallaxes or accurate V-band magnitudes; thus, it may be applied to less luminous and more distant stars than can photometric methods. Our results will inform the MEarth target list and is an important element in the census of our nearest and most abundant neighbors. ERN is supported by the National Science Foundation through a Graduate Research Fellowship. 326.09 FIRE Spectroscopy Of The Ultracool Brown Dwarf, UGPS 0722-05 John J. Bochanski1, A. J. Burgasser2, R. A. Simcoe3 1Penn State, 2UC, San Diego, 3Massachusetts Institute of Technology. 8:00 AM - 7:00 PM Essex Ballroom We present FIRE spectroscopic observations of the ultracool (T ∼ 520 K) brown dwarf, UGPS 0722-05, obtained during instrument commissioning on the 6.5m Baade Magellan Telescope at Las Campanas Observatory. At a distance of 4.1 pc, this cool brown dwarf is well-suited for detailed followup, and represents a keystone at the transition between the lowest-mass brown dwarfs and exoplanets. Our spectrum of UGPS 0722-05 covers the 0.8-2.5 micron bandpasses at a resolution of R ∼ 6,000, and is measured to high signal-to-noise, peaking at 80 near 1.27 microns. We derive radial and rotational velocities for the isolated brown dwarf, and examine its space motion and Galactic orbit. The spectrum of UGPS 0722-05 is also compared to theoretical spectral models to constrain its atmospheric parameters. Finally, we comment on the presence of unidentified absorption features reported in the discovery spectrum of Lucas et al. (2010). We thank Mauricio Martinez and the entire Magellan staff for assistance during FIRE commissioning and observations. JJB acknowledges the support of Kevin Luhman. 326.10 The Properties and Kinematics of a Sample of Cool Subdwarfs from SDSS Antonia Savcheva1 1Boston University. 8:00 AM - 7:00 PM Essex Ballroom We present a sample of 364 M subdwarfs from the 7th Data Release of the Sloan Digital Sky Survey (DR7; SDSS). This catalog contains stellar coordinates, SDSS magnitudes, spectral classes, radial velocities, proper motions, absolute magnitudes and estimated distances. We discuss the selection criteria, the spectral classification and radial velocity determination processes. We calculate 3D space motions (U,V,W) in the standard Galactic system and place each star in its proper subdwarf subclass (as efined by Lepine et al.). We show that the metal poor populations are moving faster than metal rich stars on average, consistent with being members of a dynamically heated thick disk or halo. In addition, we present an updated version of the reduced proper motion (RPM) diagram, which is useful for separating low-mass subdwarfs from their M dwarf thin disk counterparts. 326.11 Multiple Systems Abound!: New Wide Common Proper Motion Multiple Star Systems in the Lepine-Shara Proper Motion North and South Catalogs Jacqueline Faherty1, K. Bartel1, R. Stoner2, S. Wilansky1, S. Lepine1 1American Museum of Natural History, 2The Spence School. 8:00 AM - 7:00 PM Essex Ballroom Multiple star systems aid in constraining star formation models and understanding Galactic history. The focus of this poster is on wide multiple star systems detected through a cross-correlation of the Lepine-Shara Proper Motion North and South (LSPM-N,S) catalogs with themselves and with the Hipparcos catalog. Of the 1,987 systems detected, 937 were previously unidentified in the literature. The spectral types of the primaries range from B stars to M stars with a vast majority having spectral type F or G. Moreover, a large percentage of the new systems are higher order multiples. In this poster we discuss characteristics of the multiple systems including age and metallicity estimates as well as wide binary and hierarchichal system fractions in the field. 326.12 An Investigation into the Periodic Optical Variability of Radio Detected Ultracool Dwarfs using the GUFI Photometer Richard P. Boyle1, L. K. Harding2, G. Hallinan3, R. F. Butler2, A. Golden2 1Vatican Observatory, 2National University of Ireland Galway, Ireland, 3UC Berkeley. 8:00 AM - 7:00 PM Essex Ballroom In the past ten years or so, radio observations of ultracool dwarfs have yielded the detection of both quiescent and time-variable radio emission in the late-M and L dwarf regime. Four of these dwarfs have been found to produce periodic pulses, determined to be associated with the dwarf's rotation. More recently, two of these radio pulsing dwarfs have been shown to be periodically variable in broadband optical photometry, where the detected periods match the periods of the radio pulses. For one of these dwarfs in particular, it has been established that the mechanism which is driving the optical and radio periodic variability are possibly linked, being a consequence of a magnetically-driven auroral process. We therefore undertook a campaign to investigate the ubiquity of optical periodicity for known radio detected ultracool dwarfs, via multi-color photometric monitoring. To facilitate this research, the GUFI instrument (Galway Ultra Fast Imager) was commissioned on the 1.8m VATT observatory, on Mt. Graham, Arizona. We present the recently published results from this observation campaign, where we have confirmed periodic variability for five of these dwarfs, three of which have been detected for the first time by GUFI. These data provide an insight into the cause of this optical emission, its connection to the radio processes, and most importantly determine whether optical periodic signals are present only in radio pulsing dwarfs. 326.13 The ELM Survey: A Successful Targeted Survey for Extremely Low Mass White Dwarfs Warren R. Brown1, M. Kilic1, C. Allende Prieto2, S. J. Kenyon1 1Smithsonian Astrophysical Observatory, 2Instituto de Astrofisica de Canarias, Spain. 8:00 AM - 7:00 PM Essex Ballroom We present the first targeted survey for Extremely Low Mass (ELM) white dwarfs (WDs), helium core WDs with masses <0.3 M ⊙. Such low mass WDs are the signature of extreme mass-loss stellar evolution. We have discovered over a dozen new ELM WDs, most of which are compact binary systems with <1 day orbital periods. We predict that at least one of the systems is an eclipsing double-WD system that we can use to place fundamental mass-radius constraints on helium-core WD models. Intriguingly, the observed ELM WD systems are merging due to gravitational wave radiation and will become gravitational wave sources. We use our well-defined, non-kinematically-selected sample to measure the space density of ELM WD systems; their merger rate is comparable to the rate ofunderluminous supernovae, one model for which is the detonation of ~0.3 M ⊙ worth of helium. 327 Blazars, Quasars, and Other AGN Poster Session Essex Ballroom 327.01 A Continuing Blazar Monitoring Campaign at Radio Wavelengths with the Morehead State University 21-Meter Space Tracking Antenna Thomas Pannuti1, C. K. Grimes1, J. M. Tussey1, E. J. Goff1, N. D. Fite1, B. J. Cahall1 1Morehead State University. 8:00 AM - 7:00 PM Essex Ballroom The Morehead State University 21-Meter Space Tracking Antenna is a particularly unique scientific instrument for pursuing undergraduate research in astrophysics. Current research projects in the radio continuum include pointed observations of Galactic supernova remnants and blazars. In the latter case, undergraduate students and faculty have routinely conducted observations of such well-known blazars as BL Lac, CTA 102 and 3C 454.3: in addition, observations of other blazars detected in outburst at other wavelengths (such as the gamma-ray) have also been observed. We present the results of these observations and an initial analysis of the light curves generated by our observations. 327.02 Similarity of Optical-IR and Gamma-Ray Variability Properties of Fermi Blazars Ritaban Chatterjee1, C. Bailyn1, E. Bonning1, M. Buxton1, P. Coppi1, J. Isler1, C. M. Urry1 1Yale Univ.. 8:00 AM - 7:00 PM Essex Ballroom We present the time variability properties of a sample of six blazars, AO 0235+164, 3C 273, 3C 279, PKS 1510-089, PKS 2155-304, and 3C 454.3, at optical-near IR frequencies observed as a part of the Yale/SMARTS program during 2008-2010. We find the optical/IR time variability properties of these blazars to be remarkably similar to those at the gamma-ray energies as observed through Fermi. The power spectral density (PSD) of the R-band variability of all six blazars are fit well by simple power-law functions with negative slope and no significant break. The negative slope implies there is higher amplitude variability on longer than on shorter timescales. Average slope and amplitude of these PSDs are similar to those of the gamma-ray variability of a larger sample of blazars as found by the Fermi team. This is consistent with the general picture of the leptonic model where the optical-IR and gamma-ray emission is generated by the same population of electrons through synchrotron and inverse-Compton processes, respectively. The prominent flares present in the optical-IR as well as the gamma-ray light curves of these blazars are predominantly symmetric, i.e., have similar rise and decay timescales. This indicates that the long-term variability is dominated by the crossing time of radiation or a disturbance through the emission region and not by the energy-loss timescales of the emitting electrons due to radiation. The total energy output, and the gamma-ray vs. optical flux relation of six individual flares of the blazar 3C 454.3 during 2009 August to December vary significantly from one event to the other. This indicates that the location and/or mechanism of their generation are different. This work was supported by Fermi GI grant NNX09AR92G and NSF grant AST-0707627. 327.03 Intranight Optical Variability of Core Dominated Quasars and TeV Blazars Paul J. Wiita1, A. Goyal2, G. Krishna2, G. C. Anupama3, D. K. Sahu3, S. Joshi4, C. Karthick4, R. Sagar4 1The College of New Jersey, 2National Centre for Radio Astrophysics, India, 3Indian Institute of Astrophysics, India, 4ARIES, India. 8:00 AM - 7:00 PM Essex Ballroom We have investigated the intranight optical variability (INOV) of powerful flat spectrum core dominated radio quasars (CDQs) and TeV blazars to test unification models of radio-loud AGN. A sample of 15 CDQs, including both low-polarization and high-polarization objects, were observed at three sites in India on 49 nights; with data from the literature this sample was extended to 24 CDQs and 110 nights. The INOV duty cycle was about 18% for the low polarization sub-sample but about 66% for the high polarization sub-sample. Given that all these CDQs had synchrotron self-absorbed cores all should be relativistically beamed, so this difference indicates that optical polarization is more strongly linked with rapid variability than is relativistic beaming. For the first systematic attempt to characterize the INOV of TeV detected blazars we monitored 9 of them over 26 nights and have included additional data (some from our earlier studies) on 13 more for a total of 22 TeV blazars observed on 116 nights. The overall INOV duty cycle for this group is about 59%, with the LBLs distinctly more variable than the HBLs. Given that the Doppler boosting factors for TeV blazars are expected to be very high, it is somewhat surprising that no variations faster than one hour were seen for any members of the TeV sample. 327.04 A Model for Microvariability in Blazars Gopal Bhatta1, J. Webb1, S. Dhalla1, H. Hallingsworth1 1Florida International University. 8:00 AM - 7:00 PM Essex Ballroom We present a model based on the results of nearly 10 years of the study of microvariability in a sample of Blazars. The model is based on the facts that: 1) The variations do not show the characteristics of random noise, 2) The variations are not periodic, 3) The variations are best described as stochastically generated pulses of varying amplitude and durations. We show microvariability curves dissected with this interpretation in mind, and propose a theoretical underpinning for this model based on shocks encountering turbulent cells and cooling via synchrotron radiation. We show microvariations (and the lack of them) can be understood in terms of this model. We also describe an observational test to investigate the validity of this model. 327.05 Doubling the Sample of Jet Speed Measurements for the TeV Blazars B. Glenn Piner1, V. C. Tiet1, P. G. Edwards2 1Whittier College, 2CSIRO, Australia. 8:00 AM - 7:00 PM Essex Ballroom We report on our observations of the parsec-scale radio jet structures of five blazars that have been detected by ground-based TeV gamma-ray telescopes. These five blazars all belong to the class of High-frequency peaked BL Lac objects (HBLs), which are the most common blazar type detected at the TeV energy range. Because of their relative faintness in the radio, these HBLs are not well represented in other radio blazar surveys. Our observations consist of five epochs of Very Long Baseline Array (VLBA) imaging from 2006 to 2009, of each of the five blazars 1ES 1101-232, Markarian 180, 1ES 1218+304, PG 1553+113, and H 2356-309, at frequencies from 5 to 22 GHz. Fundamental jet properties, including the apparent jet speeds, that can be measured from these multi-epoch series of VLBA images are presented and compared with other gamma-ray blazars. This study approximately doubles the number of TeV blazars with multi-epoch parsec-scale structural measurements. This work was supported by the National Science Foundation under Grant 0707523. 327.06 Analysis of Parsec-Scale Jet Behavior of a Sample of Blazars during High Gamma-Ray States Svetlana G. Jorstad1, A. P. Marscher1, I. Agudo1, B. Harrison1 1Boston Univ.. 8:00 AM - 7:00 PM Essex Ballroom We present total and polarized intensity images at ultra-high resolution (0.1 milliarcseconds) of a sample of 33 gamma-ray blazars obtained monthly with the Very Long Baseline Array (VLBA) at 43~GHz, starting in Summer 2008 when the Fermi Gamma-Ray Space Telescope began to operate. The VLBA observations determine the flux and polarization of the millimeter-wave core and other components of the jet, as well as the kinematics and evolution of bright superluminal knots. We compare the gamma-ray light curves of the blazars, constructed with data provided by the Fermi Large Area Telescope, with flux and polarization variations in the VLBI core and bright superluminal knots. For all blazars in the sample that exhibit a high gamma-ray state on time scales from several weeks to several months, an increase of the total flux in the mm-wave core is contemporaneous with the gamma-ray activity (more than a third of the sample). In addition, a maximum of the degree of polarization in the core or bright superluminal knot nearest to the core occurs at the same time as the gamma-ray peak to within the accuracy of the sampling of the radio data. We discuss the locations in the jet where high gamma-ray fluxes occur, as well as the physical processes leading to luminous gamma-ray emission in blazars. This research is funded in part by NASA through Fermi Guest Investigator grants NNX08AV65G, NNX08AV61G, NNX09AT99G, and NNX10AU15G, and by the National Science Foundation through grant AST-0907893. 327.07 Simulations Of Millimeter-wave To Gamma-ray Flares Of Blazars In A Turbulent Jet Alan P. Marscher1 1Boston Univ.. 8:00 AM - 7:00 PM Essex Ballroom The author is developing a model in which much of the optical and high-energy radiation in a blazar is emitted near the 43 GHz core of the jet as seen in VLBA images, parsecs from the central engine. The main physical features are a turbulent ambient jet plasma that passes through either standing or moving shock waves in the jet. The model allows for short time-scales of optical and gamma-ray variability by restricting the highest-energy electrons radiating at these frequencies to a small fraction of the turbulent cells, perhaps those with a particular orientation of the magnetic field relative to the shock front. Because of this, the volume filling factor at high frequencies is relatively low, while that of the electrons radiating below about 10 THz is near unity. Such a model is consistent with the following observational trends: (1) red-noise power spectra of flux variations in blazars, (2) shorter time-scales of variability of flux and polarization at higher frequencies, (3) mean polarization levels as well as fractional deviations from the mean that are higher at optical than at lower frequencies, (4) apparent rotations in polarization position angle, and (5) breaks in the synchrotron spectrum by more than the radiative loss value of 0.5. The dependence of items 2-4 on frequency is directly related to the change in spectral index beyond the break, according to the model. The model includes synchrotron radiation at millimeter to X-ray wavelengths, as well as gamma-ray and X-ray emission from inverse Compton scattering. The presentation will compare simulated and actual light curves of blazars, and will discuss the physical conditions that produce good agreement. This research is supported in part by NASA through Fermi grants NNX08AV65G and NNX10AO59G, and by NSF grant AST-0907893. 327.08 The Massive Host Galaxies Of z>2 Obscured Quasars Mark Lacy1, A. O. Petric2, S. E. Ridgway3, A. Martinez-Sansigre4, A. Sajina5, D. Farrah6, T. Urrutia7 1NRAO, 2Caltech, 3CTIO/NOAO, Chile, 4University of Portsmouth, United Kingdom, 5Tufts University, 6University of Sussex, United Kingdom, 7Spitzer Science Center. 8:00 AM - 7:00 PM Essex Ballroom We have used mid-infrared selection to find several tens of dust obscured quasars at z>2. We find that many of these objects have host galaxies with high stellar masses, commensurate with their high black hole masses (assuming Eddington-limited accretion rates). In common with some other studies of obscured AGN and quasars we do not find evidence for black hole masses in excess of the local black hole mass - bulge mass relation. The molecular gas content of these objects is small compared to their stellar masses. These observations are all consistent with the quasar hosts being relatively mature systems when observed. 327.09 Optical+Near-IR Bayesian Classification of Quasars Sajjan S. Mehta1, G. T. Richards1, A. D. Myers2 1Drexel University, 2University of Illinois at Urbana-Champaign. 8:00 AM - 7:00 PM Essex Ballroom We describe the details of an optimal Bayesian classification of quasars with combined optical+near-IR photometry from the SDSS and UKIDSS LAS surveys. Using only deep co-added SDSS photometry from the "Stripe 82" region and requiring full four-band UKIDSS detections, we reliably identify 2665 quasar candidates with a computed efficiency in excess of 99%. Relaxing the data constraints to combinations of two-band detections yields up to 6424 candidates with minimal trade-off in completeness and efficiency. The completeness and efficiency of the sample are investigated with existing spectra from the SDSS, 2SLAQ, and AUS surveys in addition to recent single-slit observations from Palomar Observatory, which revealed 22 quasars from a subsample of 29 high-z candidates. SDSS-III/BOSS observations will allow further exploration of the completeness/efficiency of the sample over 2.2<z<3.5, where optical-only surveys are particularly incomplete/inefficient. 327.10 Bolometric Corrections as a Function of Ionizing Spectra for SDSS-Selected Quasars Coleman M. Krawczyk1, G. T. Richards1 1Drexel University. 8:00 AM - 7:00 PM Essex Ballroom We explore the spectral energy distribution (SED) for up to 100,000 SDSS-selected quasars using mid-IR data from Spitzer, near-IR data from 2MASS and UKIDSS, optical data from SDSS, and UV data from GALEX. We consider the problem of determining bolometric corrections for individual quasars as opposed to the ensemble average. Significant differences can arise due to the fact that even the best observed SEDs have a gap of nearly 2 decades in frequency between the UV and X-ray. We particularly consider the dependence of the bolometric correction on the UV luminosity and the properties of the CIV emission line. The latter can be used to distinguish between hard-spectrum radio-quiet quasars and soft-spectrum radio-quiet quasars, which can have very different bolometric corrections for the same UV luminosity and thus different Eddington ratios. 327.11 Red Radio-intermediate Quasars From The Wise Survey Carol J. Lonsdale1, M. Kim1, J. Condon1, M. Lacy1, A. Kimball1, T. Jarrett2, C. Tsai2, A. Blain3, WISE 1NRAO, 2IPAC, 3University of Leicester, United Kingdom. 8:00 AM - 7:00 PM Essex Ballroom The first catalog release from NASA's Wide-field Infrared Survey Explorer (WISE) mission, covering 57% of the sky, is scheduled for April. The WISE catalog has been cross-matched with the FIRST and NVSS radio surveys, resulting in ~30,000 matches to WISE mid-infrared sources. We will present overall statistics for the observed range of color and radio/mid-IR flux density ratio. A subset of ~200 radio-intermediate sources with very red optical-to-mid-IR SEDs and evidence for some extent to the 6cm radio emission has been selected for detailed study. 327.12 Modeling the Hβ Emission Lines in Luminosity-Averaged Quasar Spectra Meadows Zachary1, S. Zamfir1, P. Marziani2, J. W. Sulentic3 1University of Wisconsin - Stevens Point, 2INAF-Osservatorio Astronomico di Padova, Italy, 3Instituto de Astrofísica de Andalucia, Spain. 8:00 AM - 7:00 PM Essex Ballroom We construct median optical spectra of quasars in bins of luminosity. The sample includes bright objects from Sloan Digital Sky Survey (with z<0.7) and sources at intermediate redshift z ≈ 0.9-3.0 observed with VLT ISAAC. The whole sample spans almost six decades in luminosity 43 < log[Lbol (erg s-1)] < 49. We focus our attention to objects that show FWHM (Hβ-broad component) = 4000 - 8000 km s-1 and RFeII = W(FeII 4434-4684)/W(Hβ) less than 0.5. These quasars occupy a restricted domain in the optical plane of the 4D Eigenvector 1 (4DE1) parameter space, which is luminosity independent. We model the total profile of the broad Hβ emission line under the assumption that it requires both a classical broad component (BC) and a redshifted very broad component (VBC). We investigate the properties of the two spectral components as a function of luminosity and report our preliminary results. 327.13 CIV Emission And The Ultraviolet Through X-ray Spectral Energy Distribution Of Radio-quiet Quasars Gordon T. Richards1, N. E. Kruczek1, S. C. Gallagher2, R. P. Deo2, P. B. Hall3, P. C. Hewett4, K. M. Leighly5 1Drexel Univ., 2University of Western Ontario, Canada, 3York University, Canada, 4Institute of Astronomy, United Kingdom, 5The University of Oklahoma. 8:00 AM - 7:00 PM Essex Ballroom At high redshift two parameters span the range of emission line properties in quasar broad emission line regions: the CIV equivalent width and the blueshift of the CIV line relative to the quasar rest frame. We explore the connection between these emission line features and the UV through X-ray spectral energy distribution (SED) for radio-quiet quasars. We find that radio-quiet quasars with both strong CIV emission and small CIV blueshifts can be classified as ``hard-spectrum'' sources that are (relatively) strong the in X-ray as compared to the UV. The low-energy X-ray upturn (``soft excess'') in some quasars may be consistent with the high-energy extension of the ``big blue bump'' in hard-spectrum sources. On the other hand, RQ quasars with both weak CIV emission and large CIV blueshifts are instead ``soft-spectrum'' sources. The nature of sources with weak CIV and small blueshifts is less clear and needs further study. We argue that bolometric corrections for quasars may have systematic errors if a single mean SED is assumed for all objects, leading to additional systematic errors in accretion rates as determined by L_bol/M_vir. Bolometric corrections can instead be considered as a function of the ionizing spectrum, which can be inferred from the properties of the broad emission lines, particularly CIV. 327.14 Radio Quiet-er: The Search for Radio-Silence within CIV Emission Line Parameter Space Rachael Kratzer1, G. T. Richards1 1Drexel University. 8:00 AM - 7:00 PM Essex Ballroom Despite the debate as to whether a dichotomy between radio-loud and radio-quiet quasars actually exists, the fact remains that some quasars are radio-loud while others are not. Using median stacking analysis of SDSS quasars undetected by FIRST, we search for possible radio-silence amongst various sub-samples with different broad emission line properties. Specifically, we find that the combination of two parameters of the CIV emission line (the equivalent width and the "blueshift") can be used to determine the ionizing spectrum of individual quasars. Quasars with strong CIV are seen to have hard (ionizing) SEDs, while quasars with large blueshifts are seen to have softer SEDs. The shape of the SED depends on fundamental parameters such as mass, accretion rate, and spin; radio-loudness may be dependent on these parameters. As such, our CIV emission line parameter space affords a unique way to probe the radio properties of quasars. We predict that those radio-quiet quasars with the least ionizing spectra will have very different median stacked peak flux values than radio-quiet quasars with hard ionizing spectra. We further break our sample into smaller subsets (e.g., based on optical luminosity) to explore the radio-dependence on these parameters. Stacking subsets of quasars undetected by FIRST offers fresh new insight to a frustratingly stagnant problem. 327.15 The Kiloparsec-scale Jet Of The Quasar 3C345 David H. Roberts1, J. F. C. Wardle1, V. V. Marchenko1 1Brandeis Univ.. 8:00 AM - 7:00 PM Essex Ballroom Deep Very Large Array imaging of the quasar 3C345 has been used to study the structure, linear polarization, and magnetic field of its radio jet at 4.86 and 8.44 GHz on scales ranging from 2 to 30 kpc. There is a 7-8 Jy unresolved core with spectral index -0.24. The jet (typical intensity 15 mJy/beam) consists of a 2.5 arcsec straight section containing two knots, and two additional non-co-linear knots at the end. The spectral index of the jet varies between -1.1 and -0.5. The main body of the jet diverges slightly, with an apparent opening half-angle of about 8 degrees; de-projected, the intrinsic opening angle is probably about 1-2 degrees. Surprisingly, the inferred magnetic field direction in the interior of the main body of the jet is neither longitudinal nor transverse, but makes an angle of about 55 degrees with the jet axis, in an apparent helix. There is no significant Faraday rotation in the source, so that is not the cause of the field twist. The fractional polarization in the jet averages 25%, while that of the core is only 3%. Despite the indication of jet precession in the total intensity structure, the polarization images suggest instead a jet re-directed at least twice by collisions with the external medium. Simple models of magnetized jets are investigated in order to study various possible origins of the magnetic field morphology. In a cylindrically symmetric transparent jet a helical magnetic field would appear either transverse or longitudinal due to partial cancellations of Stokes parameters. Synchrotron opacity can break the symmetry, but it leads to fractional polarization far less than that observed. We investigate whether differential Doppler boosting in a diverging jet can break the symmetry, allowing a truly helical jet to appear helical. 327.16 Nozzle Analysis and Line-Driven Disk Winds in QSOs Nicolas Antonio Pereyra1 1University of Texas - Pan American. 8:00 AM - 7:00 PM Essex Ballroom An analytic method for determining the existence or non-existence of steady line-driven solutions is implemented for disk winds with QSO parameters. This method is independent of numerical time-dependent computationally-intensive simulations , and it is found that steady disk wind solutions for QSOs do exist. This is consistent with the steady wind outflow velocity structure observed in QSOs. 327.17 Probing Emission And Absorption Processes In AGNs With MHD Accretion-Disk Winds Keigo Fukumura1, D. Kazanas2, E. Behar3, I. Contopoulos4 1CRESST/UMBC/GSFC, 2NASA/GSFC, 3Department of Physics, Technion, Israel, 4Academy of Athens, Greece. 8:00 AM - 7:00 PM Essex Ballroom It is well known from the past optical/EUV observations that a small population of AGNs exhibits the so called broad double-peaked Balmer line profiles (FWHM~10,000 km/sec); i.e. ~20% of the radio-galaxies (RGs) and radio-loud (RL) AGNs at z<0.4 while only 3-4% of SDSS AGNs at z<0.33 (e.g. Arp 102B and 3C 390.3). Its theoretical interpretation has been based on a Keplerian accretion disk where line photons are Doppler-shifted due to rotation to form the broadened red/blue tails although the predicted line strength is critically smaller than the observed intensity. As an alternative explanation to resolve this issue, we propose that magnetically-driven disk-winds can self-consistently reproduce both i) broad double-peaked line shape and ii) its normalization for many observed objects including those with single-peaked profiles. Our preliminary results suggest that the apparent spectral distinction in various Balmer lines can be accounted for by the wind structure as well as viewing angle. This line emission model is a continuation of our earlier work on absorption lines for Seyfert AGNs and BAL quasars, and we here demonstrate how both spectral signatures can be explained within this single disk-wind scenario. 327.18 Origins of X-Shaped Radio Galaxies Robert Sobczak1, J. Starr1, P. J. Wiita1 1The College of New Jersey. 8:00 AM - 7:00 PM Essex Ballroom Four viable explanations for the development of the characteristic morphology of X-shaped radio galaxies (XRGs) have been presented in the literature. These established models involve: backflowing material from relativistic jets deflected off the host galaxy ISM; over-pressured cocoons leading to outflow along a galaxy’s minor axis; rapid jet reorientation (spin-flip), presumably involving the merger of two supermassive black holes; or the interaction of jets with stellar and gaseous shells that arise from the merger of two galaxies. None of these models appears to be able to account for the morphology of all observed XRGs, but images of these sources can be used to decide which of these models provide good fits to individual XRGs. We have examined a sample of 100 XRG candidates and tabulated several different measured parameters based on their morphology and power. The key morphology parameters are the lengths and widths of the primary and secondary lobes. We then classified the XRGs in this sample as to the most likely model or models able to explain their characteristics. Our main conclusion is that the spin-flip and jet interaction with shells models provide better fits to the majority of sources than do the backflow or over-pressured cocoon models. 327.19 Modeling and Classifying X-Shaped Radio Galaxies Julian Starr1, R. Sobczak1, P. J. Wiita1 1The College of New Jersey. 8:00 AM - 7:00 PM Essex Ballroom While there are many explanations for the formation of the apparently small subset of radio galaxies that display an X-shaped morphology (XRGs), an important but often overlooked aspect of observing XRGs is the substantial problem encountered due to projection effects. A physically well-defined XRG will not appear X-shaped if viewed from certain angles. Thus, it is quite probable that many galaxies that have been observed and classified as having other shapes, in particular, some of the double-double radio sources, may in fact be XRGs. To more accurately determine the likelihood of an XRG appearing non-X-shaped, we developed a computer algorithm to model fiducial XRGs and develop probabilities of an observation leading to classification errors due to projection effects. The program randomly generates viewing angles for different XRG models, and these are then categorized as to whether or not they appear X-shaped to the observer. Knowing they are in fact X-shaped, however, provides a statistical probability for observing an XRG and yet misclassifying its shape. By repeating this process for many viewing angles and for a variety of XRG models, we are able to analyze the likelihood of actual XRGs appearing non-X-shaped. 327.20 Determining the Contribution to Feedback from Low Accretion Rate AGN Lisa M. Winter1 1CASA/University of Colorado-Boulder. 8:00 AM - 7:00 PM Essex Ballroom While feedback from the central supermassive black hole likely affects the host galaxy evolution in the distant universe, we can not directly observe these processes at work. We can, however, easily observe the host galaxy and AGN properties of nearby sources. Previous surveys of outflows in local AGN relied on biased samples of the UV/soft X-ray brightest sources, making their results also biased. To understand the true outflow properties in a local sample of AGN, we present our results from optical and X-ray spectroscopic follow-ups of a sample of Seyfert 1s detected in the very hard X-rays (14-195 keV) with the Swift Burst Alert Telescope. Due to the high energy selection, this survey is largely unbiased to the gas and dust which obscures softer bands. We find that outflows are detected in a majority of the sample and may be present in all local Seyfert 1s. This implies a covering fraction of the outflows much larger than previous results, which means that more kinetic energy is available in the outflows of low luminosity sources than previously thought. 327.21 A Decade of Variability in Centaurus A: Results from Chandra/ACIS Observations Matthew Barger1, T. Calnan1 1Elon University. 8:00 AM - 7:00 PM Essex Ballroom We present results from a decade of Chandra observations of the nucleus in the nearest radio-loud AGN, Centaurus A. We use Chandra’s exquisite spatial resolution to separate the unresolved nucleus from emission associated with the jet, gas, and X-ray binaries, thereby allowing us to probe variability on scales less than the Bondi radius. We search for variability in the absorbing column and power-law emission, and interpret our results in the context of AGN unification models. 327.22 Suzaku Spectra of NGC 5548 and MCG--6-30-15: What Drives Broad Fe Kα Emission? Laura Brenneman1, M. Elvis1 1Harvard-Smithsonian Center for Astrophysics. 8:00 AM - 7:00 PM Essex Ballroom Broad iron K emission lines are not always seen in the X-ray spectra of type 1 AGN, in spite of their high accretion rates that imply an optically-thick disk extending down to at or near the innermost stable circular orbit (ISCO), and the unobscured line-of-sight to their X-ray sources. The reason for the notable lack of relativistic disk signatures in many type-1 AGN is unknown. We have made high S/N (~600,000 counts) Suzaku observations of NGC 5548 to set tight limits on any broad Fe K line at EW<40 eV in the summed spectrum,or <100 eV in most of the individual spectra. We compare the properties of NGC 5548 with the famously strong broad Fe K emitter MCG--6-30-15. The two AGNs are similar in several parameters (X-ray luminosity, optical-to-X-ray slope, host type), but differ strongly in black hole mass (a factor ~15), radio-loudness (a factor ~10, though both are formally radio-quiet) and Eddington ratio (a factor ~50). The low Eddington ratio (~2%) of NGC 5548 is close to the transition value to a jet-dominated low/hard state in X-ray binaries, where the inner accretion disk has withdrawn, which would narrow any relfected line emission. The higher radio-loudness of NGC 5548 may then be related to a nascent jet. However, this scenario is complicated by the presence of strong optical and UV emission lines indicating the presence of an optically-thick disk at small radii. We also examine where the X-ray continuum in NGC 5548 could originate in light-bending models in order to explain the lack of a broad Fe K line. 327.23 Narrow Line Seyfert 1 Galaxies from the Final Data Release of SDSSII Aycha Tammour1, P. B. Eskridge1 1Minnesota State University. 8:00 AM - 7:00 PM Essex Ballroom We present a study of a sample of Narrow Line Seyfert 1 (NLS1) candidates extracted from the seventh data release of the Sloan Digital Sky Survey SDSSII. The sample is restricted to objects from the QSO database that are detected by ROSAT and have z < 0.39, FWHM(Hα) < 4000 km.s−1 and FWHM(Hβ) < 4000 km.s−1 as determined by the SDSS pipeline. We fit Hβ with a Gaussian and a Lorentzian in order to examine the various properties of the spectra with the width of the Lorentzian Hβ. We also look at the properties of the sample above the classic NLS1 cut-off of FWHM(Hβ) < 2000 km.s−1 . We gratefully acknowledge the financial support from the College of Science, Engineering and Technology, and from the College of Graduate Studies at Minnesota State University. A.T. acknowledges the support from the US Department of State -The Fulbright Program and the AMIDEAST. 327.24 The Elusive Radio Loud Seyfert 2 Galaxy NGC 2110 Volker Beckmann1, O. Do Cao2 1APC, Francois Arago Centre, France, 2Laboratoire AIM Paris-Saclay, CEA/Irfu, France. 8:00 AM - 7:00 PM Essex Ballroom The AGN NGC 2110 presents a peculiar case among the Seyfert 2 galaxies, as it displays also features of radio-loud objects and is classified as FR-I radio galaxy. Here we analyse simultaneous INTEGRAL and Swift data taken in 2008 and 2009. We reconstruct the spectral energy distribution in order to provide further insight. The combined X-ray spectrum is well represented by an absorbed cut-off power law model plus soft excess. Combining all available data, the spectrum appears flat (photon index 1.25 ± 0.04) with the high-energy cut-off being at E_C = 82 ± 9 keV. The absorption is moderate (NH = 4E22 1/cm**2), the iron K-alpha line is weak (EW = 114 eV), and no reflection component is detected in the INTEGRAL spectrum. The data indicate that the X-ray spectrum is moderately variable both in flux and spectral shape. The 2008 spectrum is slightly steeper (photon index 1.5, E_C = 90 keV) with the source being brighter, and flatter in 2009 (photon index 1.4, E_C = 120 keV) in the lower flux state. The spectral energy distribution gives a bolometric luminosity of L = 2E44 erg/sec. NGC 2110 appears to be a borderline object between radio loud narrow line Seyfert 1 and radio quiet Seyfert 2. Its spectral energy distribution might indeed be dominated by non-thermal emission arising from the jet. 327.25 First Optical Spectra of Newly Detected Swift BAT AGN James Hogg1, L. M. Winter1, J. Tueller2, W. Baumgartner2 1University of Colorado, 2NASA GSFC. 8:00 AM - 7:00 PM Essex Ballroom We acquired optical spectra of ten newly discovered Swift BAT AGN for the first time and determined redshifts, optical properties, and classifications for each galaxy. The sources were detected in the 55-month survey in the hard X-ray regime of 14-195 keV. The BAT sample provides an unbiased look at AGN because at these wavelengths dust and gas obscuration does not prevent their detection. The optical follow-ups were done on the 3.5-meter Apache Point Observatory in New Mexico using the lower dispersion DIS gratings, which provides a large wavelength coverage. As the Swift survey continues, it probes to fainter and more distant objects. For the new AGN in the catalog, we present an analysis of the optical and X-ray spectroscopy. Optical spectroscopy of these new targets, discovered as AGN for the first time through their hard X-ray flux, are more distant than the average Swift source with a redshift range of z= 0.02 to 0.15 and an average redshift in the sample of z= 0.07. Half (5 sources) of our sample exhibit broad lines in their optical spectra, which is characteristic of Seyfert 1 galaxies, while the other half have narrow emission lines which are characteristic of Seyfert 2 galaxies. Additionally, we analyzed the X-ray spectra and created SEDs for these sources. 327.26 Multi-wavelength Diagnostics of the AGN/Star-formation Connection Stephanie M. LaMassa1 1Johns Hopkins Univ.. 8:00 AM - 7:00 PM Essex Ballroom We are studying the relationship between black hole growth and star formation activity using a sample of ~300 star-forming and composite AGN/star-forming galaxies and a sample of ~50 AGN dominated sources. Using Spitzer IRS and Sloan Digital Sky Survey (SDSS) spectra, we will investigate the optical and mid-infrared parameter space in which these sources live. We will present the relationships among proxies that trace intrinsic AGN luminosity (e.g. [OIII] 5007 Angstrom, [NeV] 14 micron and mid-infrared continuum luminosities), star formation activity (e.g. optically derived star formation rates from SDSS and IR star formation rates from the [NeII] 12.8 micron and [NeIII] 15.6 micron emission lines, polycyclic aromatic hydrocarbon (PAH) luminosities) and the relative importance of AGN and starburst processes (e.g. PAH equivalent widths, the optical ``D'' parameter, the mid-infrared spectral index, ionization field hardness). For the sample of AGN, we will include the soft X-ray (0.5 - 2 keV) perspective, from Chandra and XMM-Newton analysis, on the relative contributions of AGN to star formation activity. 328 Surveys and Large Programs Poster Session Essex Ballroom 328.01 CANDELS: The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey Henry Closson Ferguson1, CANDELS collaboration 1STScI. 8:00 AM - 7:00 PM Essex Ballroom The Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS) is designed to document the first third of galactic evolution, from redshift z ~ 8 to 1.5. It will image more than 250,000 distant galaxies using three separate cameras on board the Hubble Space Telescope, from the mid-UV to near-IR. It will also find and measure Type Ia SNe beyond z > 1.5 and test their accuracy as standard candles for cosmology. Five premier multi-wavelength sky regions are selected. Each has multi-wavelength data from Spitzer and other facilities, plus extensive spectroscopy of the brighter galaxies; additional ancillary data are still arriving. The use of five widely separated fields mitigates cosmic variance and yields statistically robust and complete samples of galaxies down to a stellar mass of a billion solar masses out to z ~ 2, and down to the knee of the UV luminosity function of galaxies out to z ~ 8. The survey covers approximately 800 square arcminutes and is divided into two parts. The CANDELS/Deep survey (5 σ point-source limit H_AB = 27.8 mag) covers ~ 125 square arcminutes within GOODS-N and GOODS-S. The CANDELS/Wide survey includes GOODS and three additional fields (EGS, COSMOS, and UDS) and covers the full area to 5 σ point-source limit of H_AB = 27.0 mag or better. Data from the survey are non-proprietary, and high-level science products are released within 3 months of each observation. 328.02 Tracing the Mass Assmebly at Large Radii of Massive Quiescent Galaxies Elizabeth J. McGrath1, D. Koo1, M. Mozena1, S. Faber1, A. van der Wel2, S. Wuyts3, A. Koekemoer4, CANDELS Collaboration 1University of California, Santa Cruz, 2MPIA, Germany, 3CfA, 4STScI. 8:00 AM - 7:00 PM Essex Ballroom Using high-resolution imaging data from the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS), we examine the growth of spheroids from z~2.5 to the present. Evidence that massive quiescent galaxies undergo dramatic size evolution since z~2.5 has been steadily increasing. The compact sizes of high-redshift quiescent galaxies imply densities that are up to two orders of magnitude greater than galaxies in the local Universe of similar mass. However, it is unclear whether measurements to-date, many of which have relied on rest-frame near-UV imaging, have been underestimated due to effects such as signal-to-noise and age or metallicity gradients. Recently it has been suggested that these compact galaxies could survive as the cores of massive ellipticals in the local Universe, growing low-surface-brightness halos through dry mergers, thus preserving the central mass density while increasing the effective radii. The depth of CANDELS imaging at both rest-frame near-UV and optical wavelengths allows us to reliably measure sizes and color gradients of passive galaxies for the first time over a large region of the sky, enabling us to determine when early-type galaxies start to grow their halos and how they evolve onto the local size-mass relation. 328.03 First Results On High-redshift AGN Candidates From The CANDELS Survey Anton M. Koekemoer1, J. Donley1, N. Grogin1, N. Hathi2, D. Kocevski3, R. Lucas1, J. Trump3, C. Conselice4, S. Faber3, H. Ferguson1, R. Chary5, CANDELS Collaboration 1STScI, 2OCIW, 3UCSC, 4Nottingham, United Kingdom, 5Caltech. 8:00 AM - 7:00 PM Essex Ballroom Initial results are presented on searches for high-reshift AGN candidates using the new WFC3/IR data obtained as part of the CANDELS survey, including the GOODS, UDS and EGS fields. Obtaining constraints on the numbers of AGN at high redshifts is crucial for improving our understanding of their growth and evolution as well as their relationship to their host galaxies, especially important for the physical processes that underlie the M-sigma relation. Yet obtaining sufficiently large samples of z>6 AGN has proved elusive to date, due to their low surface density as well as their faint magnitudes. The new deep WFC3/IR imaging provided by the CANDELS survey offers the first opportunity to obtain sufficiently large samples of these sources to be able to constrain the evolution of the AGN luminosity function up to high redshift, with corresponding implications for the co-evolution of galaxies and their central supermassive black holes. 328.04 Optical And Near-infrared Variability Among Distant Galactic Nuclei Of The CANDELS UDS Field Norman A. Grogin1, A. Rajan1, A. M. Koekemoer1, C. J. Conselice2, D. D. Kocevski3, R. A. Lucas1, D. Rosario4, C. Villforth1, CANDELS Collaboration 1Space Telescope Science Institute, 2University of Nottingham, United Kingdom, 3UC Santa Cruz, 4Max-Planck-Institute for Extraterrestrial Physics, Germany. 8:00 AM - 7:00 PM Essex Ballroom The CANDELS HST Multi-cycle Treasury Program completed its observations of the UKIDSS UDS field in January 2011. The coverage comprises WFC3/IR exposures in J and H across a contiguous ≈200 square arcminutes, and coordinated parallel ACS/WFC exposures in V and I across a contiguous ≈250 square arcminutes that largely overlaps the WFC3/IR coverage. These observations were split between two epochs with ≈52-day spacing for the primary purpose of high-z supernovae (SNe) detection and follow-up. However, this combination of sensitivity, high resolution, and time spacing is also well-suited to detect optical and near-infrared variability ("ONIV") among ≈10000 moderate-z galaxy nuclei (≈7500 in the near-infrared to AB∼24 mag; ≈7500 in the overlapping optical to AB∼25 mag) on rest-frame timescales of up to several weeks. The overwhelming majority of these variable galaxy nuclei will be AGN; the small fraction arising from SNe have already been meticulously culled by the CANDELS high-z SNe search effort. These ONIV galaxy nuclei potentially represent a significant addition to the census of distant AGN subject to multi-wavelength scrutiny with CANDELS. We present the preliminary results of our variability analysis, including a comparison of the HST ONIVs with the known AGN candidates in the field from deep Spitzer and XMM-Newton imaging across the field, and from extensive optical spectroscopy. We also assess the redshift distribution of the ONIVs from both spectroscopy and from robust SED-fitting incorporating ancillary deep ground-based imaging along with the CANDELS VIJH photometry. 328.05 A Comparison Of GOODS NICMOS Survey And CANDELS WFC3 H-band Galaxy Morphologies In The GOODS-South Field Ray A. Lucas1, N. A. Grogin1, C. J. Conselice2, A. Koekemoer1, A. Bauer3, CANDELS Collaboration, GOODS NICMOS-H Survey Collaboration 1STScI, 2University of Nottingham, United Kingdom, 3AAO, Australia. 8:00 AM - 7:00 PM Essex Ballroom The large amount of Hubble Space Telescope near-infrared imaging done in the GOODS-South field in both NICMOS and now WFC3 IR allows us to make a comparison and to some degree a calibration of how well one may assume the measurements made from data taken with one camera may be related to similar measurements of objects in earlier publications and/or other fields where data from only one camera are present. We are performing such a comparison on the H-band data from the GNS GOODS-South observations and the CANDELS WFC3 IR data on the same field. In all of these comparisons, despite some possible differences due to the detector resolution, efficiency, filter throughput, and resulting SExtractor catalogs, etc. for given objects, we will be comparing data on the same galaxies which were imaged with different cameras in the same basic bandpass, using standard quantitative morphological parameters. From this, one may be able to determine how well one can in general extrapolate measurements of objects made with one camera to those made with the other in various fields across the sky, and this may offer some guidance for interpretation of reliability of morphological results when reading older papers or measuring morphological parameters where only NICMOS data is available, for example. 328.06 Morphology Of GOODS-Herschel Selected ULIRGs In CANDELS Jeyhan S. Kartaltepe1, M. Dickinson1, A. Koekemoer2, GOODS-Herschel Collaboration, CANDELS Collaboration 1National Optical Astronomy Observatory, 2Space Telescope Science Institute. 8:00 AM - 7:00 PM Essex Ballroom Ultraluminous Infrared Galaxies (ULIRGs, L_IR>10^12 L⊙) in the local universe are all interacting and merging galaxies. To date, studies of ULIRGs at high redshift have found a variety of results due to their varying selection effects and small sample sizes. Here, we present the results of a morphological analysis of a sample of high redshift (z~1-3) ULIRGs. These galaxies are selected based on their infrared luminosities measured using 100 and 160 micron data from the GOODS-Herschel coverage of GOODS-S. We visually classified all of the ULIRGs as well as a comparison sample at the same redshift covering the same H band magnitude range using ACS and WFC3 data from the GOODS and CANDELS surveys. We compare our results to those from other classifiers as well as several automated classification methods. The high resolution and increased sensitivity of WFC3 over NICMOS for this large sample of objects allows us to investigate the role of galaxy mergers among high redshift ULIRGs consistently for the first time. 328.07 Clumps of z~2 Star-forming Galaxies Yicheng Guo1, M. Giavalisco1, P. Cassata1, CANDELS Collaboration 1University of Massachusetts, Amherst. 8:00 AM - 7:00 PM Essex Ballroom We study the properties of red clumps of star-forming galaxies at z~2. A sample of 15 galaxies with spectroscopic redshift is selected from the HUDF, where ultra--deep and high- resolution optical (HST/ACS) and near--IR (HST/WFC3 IR) images are available to resolve the internal structure of z~2 galaxies at the kpc scale. We generate rest-frame UV-optical color maps of these galaxies after carefully matching image PSFs. Clumps are identified through visual inspection on the (z-H) maps. We run SED-fitting using the seven-band BVizYJH HST photometry of each pixel and measure the spatial distributions of stellar population parameters, such as stellar mass, star-formation rate, age and obscuration. In order to understand the origin of sub-galactic structures, we study the distributions of these properties of the pixels that are part of clumps and compare them with those of the surrounding disks. Our results help answer two questions: (1) whether the clumps are the progenitor of bulges and (2) whether old stellar populations (with age of a few Gyr) exist in star-forming galaxies at z~2. 328.08 The Bivariate Size-luminosity Distribution Of Z~4-5 LBGs In The Goods Fields Kuang-Han Huang1, H. C. Ferguson2, S. Ravindranath3 1Johns Hopkins University, 2Space Telescope Science Institute, 3Inter-University Center for Astronomy and Astrophysics, India. 8:00 AM - 7:00 PM Essex Ballroom We study the bivariate size-luminosity distribution of z~4 and z~5 Lyman Break Galaxies (LBG) in the GOODS fields. Our sample was selected using the Lyman Break color selection criteria in order to select rest-frame UV-bright star forming galaxies. We selected around 1250 B-dropouts (z~4) and 370 V-dropouts (z~5) in both GOODS fields and the HUDF field, down to ACS F850LP magnitude z_{850} = 26.5 (GOODS ACS dataset) and z_{850}=28.0 (HUDF dataset). We model the size distribution as a lognormal distribution and the luminosity function in the Schechter function form, and connect them with a power law relation between the peak size $r_0$ and the absolute magnitude $M$, $r_0 = r*(M/M*)^{\beta}$. Galaxy magnitude and size are measured first with SExtractor, then we use GALFIT to fit a single Sersic component to derive the effective radius. We also performed a Monte Carlo simulation in order to account for the measurement bias and scatter of SExtractor and GALFIT. The result of the simulation is convolved with the size-luminosity distribution models to compare with the observed distributions. We will compare our best-fit distribution with the luminosity functions published in the literature at similar redshifts. 328.09 The Morphologies of BOSS Target Galaxies from COSMOS HST Imaging Karen L. Masters1, C. Maraston1, A. Beifiori1, A. Leauthaud2, R. Mandelbaum3, R. Nichol1, D. Thomas1, K. Bundy4, J. Pforr1, N. Ross2, R. Skibba5, SDSS3 Collaboration 1ICG, University of Portsmouth, United Kingdom, 2Lawrence Berkeley National Laboratory, 3Princeton University, 4UC Berkeley, 5University of Arizona. 8:00 AM - 7:00 PM Essex Ballroom The SDSS-III Baryon Oscillation Spectrocopic Survey (BOSS) will measure redshifts for 1.4 million massive galaxies between 0.2 5 as a proxy for early star formation, feedback and enrichment. This contribution describes results from the first year of FIRE's operation, including measurements of the C IV abundance at z > 5.5 and the Mg II abundance at 2.5 < z < 6. FIRE's construction and early science observations are supported by the National Science Foundation, and the Curtis Marble Fund at MIT. 333 Astronomy Education & Public Outreach Poster Session America Ballroom Foyer 333.01 Dark Energy is “Dying” and Other Student Ideas About Cosmology Janelle M. Bailey1, K. Coble2, G. L. Cochran3, R. Sanchez1, D. Larrieu2, V. L. Hayes2, M. Nickerson2, L. R. Cominsky4, K. M. McLin4 1Univ. Nevada, Las Vegas, 2Chicago State Univ, 3Florida International Univ, 4Sonoma State Univ. 8:00 AM - 7:00 PM America Ballroom Foyer Determining the range and frequency of “alternative conceptions” is an important first step to improving instructional effectiveness. Modern topics in astronomy, such as cosmology, are of primary interest to many educators and students, but we are only beginning to understand students’ alternative conceptions in this area. Through analysis of pre-instructional open-ended surveys (N > 500), our research group is attempting to classify students’ ideas about concepts important to modern cosmology, including the structure, age, and evolution of the universe; dark matter and dark energy; and the Big Bang. Survey responses, analyzed through an iterative process of thematic coding, reveal a number of alternative conceptions. For example, students frequently conflate structure terms such as solar system, galaxy, and universe or do not understand the relationship between the terms; believe the universe to be infinitely old; and may not be aware of dark matter or dark energy. This work was supported by NASA ROSES E/PO Grant #NNXlOAC89G, as well as by the Illinois Space Grant Consortium and National Science Foundation CCLI Grant #0632563 at Chicago State University and the Fermi E/PO program at Sonoma State University. 333.02 Investigating Student Understanding of the Universe: Dark Matter Melissa Nickerson1, K. Coble1, G. L. Cochran2, V. L. Hayes1, C. T. Camarillo1, J. M. Bailey3, K. M. McLin4, L. R. Cominsky4 1Chicago State University, 2Florida International University, 3University of Nevada, 4Sonoma State University. 8:00 AM - 7:00 PM America Ballroom Foyer Student pre-course surveys reveal that students who enter the classroom have little knowledge or understanding of the concept of dark matter (DM). At Chicago State University, we enthusiastically introduce this concept to students through interactive tutorials and hands-on inquiry-based laboratory activities. We have analyzed pre and post laboratory assessments and student interviews to determine the extent to which these tutorials have helped our students to gain a more robust understanding of the topic. The results of this work will be presented. This project is a part of our efforts at CSU to reform our introductory astronomy course. This project is part of a larger study; also see our posters on student ideas about the age and expansion of the universe, the structure of the universe, and perceptions of astronomical sizes and distances. This work was supported by NASA ROSES E/PO Grant #NNXlOAC89G, as well as by the Illinois Space Grant Consortium and National Science Foundation CCLI Grant #0632563 at Chicago State University and the Fermi E/PO program at Sonoma State University. 333.03 Investigating Student Understanding of the Universe: Age and Expansion Kimberly A. Coble1, G. L. Cochran2, V. Hayes1, M. Nickerson1, C. T. Camarillo1, J. M. Bailey3, K. M. McLin4, L. R. Cominsky4 1Chicago State Univ., 2Florida International University, 3University of Nevada, 4Sonoma State Univ.. 8:00 AM - 7:00 PM America Ballroom Foyer At Chicago State University we are reforming our introductory astronomy course. As a part of this effort, we seek to bring the tools and advances of recent cosmological research to the classroom by developing curricular materials that support students in learning cosmological topics using real data and cosmological research methods. Analysis of pre-course surveys, pre-course essays, and pre-instructional interviews indicate that students bring to the classroom an array of incorrect ideas regarding the age of the universe. Analysis of assessments, post-instructional interviews, and student comments on laboratory activities indicate that their ideas on this topic have changed to be more in line with scientific evidence. Yet, students still struggle perform the measurements and calculations necessary to determine the age of the universe or explain the expansion of the universe after instruction. This project is part of a larger study; also see our posters on student ideas about dark matter, the structure of the universe, and perceptions of astronomical sizes and distances. This work was supported by NASA ROSES E/PO Grant #NNXlOAC89G, as well as by the Illinois Space Grant Consortium and National Science Foundation CCLI Grant #0632563 at Chicago State University and the Fermi E/PO program at Sonoma State University. 333.04 Investigating Student Understanding of the Universe: Structure Virginia Hayes1, K. Coble1, M. Nickerson1, G. Cochran2, C. T. Camarillo1, J. M. Bailey3, K. M. McLin4, L. R. Cominsky4 1Chicago State University, 2Florida International University, 3University of Nevada, 4Sonoma State University. 8:00 AM - 7:00 PM America Ballroom Foyer Chicago State University (CSU) offers an introductory astronomy course that services students from a variety of majors including pre-service teachers. At CSU, we have been investigating methods and tools that will improve student conceptual understanding in astronomy for this diverse group of students. We have analyzed pre-course surveys, pre-course essays, exams, and interviews in an effort to better understand the ideas and difficulties in understanding that students have in regards to the structure of the universe. Analysis of written essays has revealed that our students do have some knowledge of the objects in the universe, but interviews inform us that their understanding of the structure of the universe is superficial. This project is a part of a larger study; also see our posters on student ideas about dark matter, the age and expansion of the universe, and perceptions of astronomical sizes and distances. This work was supported by NASA ROSES E/PO Grant #NNXlOAC89G, as well as by the Illinois Space Grant Consortium and National Science Foundation CCLI Grant #0632563 at Chicago State University and the Fermi E/PO program at Sonoma State University. 333.05 Investigating Student Understanding of the Universe: Perceptions of Astronomical Sizes and Distances Carmelita Camarillo1, K. Coble1, V. Hayes1, M. Nickerson1, G. L. Cochran2, J. M. Bailey3, K. M. McLin4, L. R. Cominsky4 1Chicago State University, 2Florida International University, 3University of Nevada, 4Sonoma State University. 8:00 AM - 7:00 PM America Ballroom Foyer Student perceptions regarding astronomical sizes and distances are being analyzed for Chicago State University’s Basic Astronomy course. This area is of great interest to further understand the students’ learning processes and to produce more effective instruction. Insights from cognitive psychology have shown that perceptions are related to prior experiences and current knowledge. Students enter into this course with different mental representations, and these representations can affect their learning. Through a repeated measures design, perceptions are analyzed through several instruments. The instruments implemented are pre-tests surveys (before lab), exams (after lab), lab comments, and interviews. Preliminary analysis reveals that students who have difficulty with astronomical sizes and distances have been more strongly influenced by culture and the media whereas those who had less difficulty expanded on their personal prior experiences. This project is part of a larger study; also see our posters on the structure of the universe, dark matter, the age and expansion of the universe. This work was supported by NASA ROSES E/PO Grant #NNXlOAC89G, as well as by the Illinois Space Grant Consortium and National Science Foundation CCLI Grant #0632563 at Chicago State University and the Fermi E/PO program at Sonoma State University. 333.06 Integration of Galileoscopes into a Large MathMovesU Program Robert T. Sparks1, C. E. Walker1, S. M. Pompea1 1NOAO. 8:00 AM - 7:00 PM America Ballroom Foyer The Galileoscope is a small, low cost, high optical quality telescope kit developed for the International Year of Astronomy 2009. In 2010 and 2011, the National Optical Astronomy Observatory (NOAO) has partnered with Raytheon, the University of Arizona Office of Early Academic Outreach and the Tucson Amateur Astronomy Association to build hundreds of Galileoscopes as part of Raytheon’s Math Moves U program. Each of these events involved building Galileoscopes with hundreds of students at the same time. We had the assistance of about 70 Raytheon engineers who were participating in the Executive Leadership Development Program (ELDP’s). Prior to the MMU event, the ELDP’s were trained how to build Galileoscopes. One ELDP was stationed at each table of students to help build the Galileoscopes during the event. The 2010 event involved over 450 eighth grade students from schools in Tucson. The students were predominantly from an underserved population in the Sunnyside School District. The 2011 event reached 350 high school juniors from Tucson, Sierra Vista, and Nogales, Arizona who were part of the GEAR UP program. GEAR UP students come primarily from underserved populations at schools in Tucson, Sierra Vista, and Nogales. We will discuss the process of planning and running large scale Galileoscope events including planning, logistics, setup, and training volunteers. 333.07 The Flagstaff Star Party Model for Using Galileoscopes: Evaluation Report Stephen M. Pompea1, R. T. Sparks1, C. Dugan1, E. Dokter2, K. Schindler3 1NOAO, 2University of Arizona, 3Lowell Observatory. 8:00 AM - 7:00 PM America Ballroom Foyer The Galileoscope is a low-cost, high optical quality telescope kit designed for education and outreach during the International Year of Astronomy 2009. The Galileoscope has been used in a variety of formal and informal education settings around the world. We have been developing a model for large star parties by collaborating with school districts and Science Foundation Arizona. We held our first large start party last fall in Flagstaff and have our next one scheduled for April of 2011 in Yuma, Arizona. The model we are using includes and extensive professional development component for teacher. Each teacher attends a day-long professional development workshop that covers the optics of a telescope, how to assemble a Gaileoscope and how to make astronomical observations. Each teacher receives an optics eduction kit including all the materials necessary to do the activities in their classrooms. The teachers receive Galileoscopes and tripods for their classrooms as well. Before the star party, NOAO staff visit the classrooms to assist students and teachers with the Galileoscope and to teach observing techniques to ensure all the Galileoscopes are working and can be used at the star party. The evening of the star party students gather at the site (usually a local park or school grounds) for an evening of observing. Each student tries to find a variety of different objects to get their passports stamped. At the end of the evening, a drawing is held for students who have observed the designated objects. We will detail the process of planning and holding the star party including professional development, logistics and follow up with the students. 333.08 Engaging the Public in the Citizen Science GLOBE at Night Campaign Constance E. Walker1, R. T. Sparks1, S. M. Pompea1 1NOAO. 8:00 AM - 7:00 PM America Ballroom Foyer The emphasis in the international star-hunting campaign, GLOBE at Night, is in bringing awareness to the public on issues of light pollution. Light pollution threatens not only observatory sites and our “right to starlight”, but can affect energy consumption, wildlife and health. GLOBE at Night has successfully reached a few 100,000 citizen-scientists. What steps can be taken to improve it? To promote the campaign via popular social media, GLOBE at Night created Facebook and Twitter pages. To increase participation in the 2011 campaign, children and adults submitted their sky brightness measurements in real time with smart phones or tablets using the web application at www.globeatnight.org/webapp/. With smart phones and tablets, the location, date and time register automatically. For those without smart mobile devices, user-friendly tools on the GLOBE at Night report page were reconfigured to determine latitude and longitude more easily and accurately. To increase the robustness of the data, 2 new approaches were taken. GLOBE at Night prototyped an “Adopt a Street” program in Tucson. The aim was for people to adopt different major or semi-major streets and take measurements every mile or so for the length of the street. The grid of measurements would canvas the town, allowing for comparisons of light levels over time (hours, days, years) or search for dark sky oases or light polluted areas. The increase to 2 campaigns in 2011 re-enforces these studies. The intent is to offer the program year-round for seasonal studies. The data can also be used to compare with datasets on wildlife, health, and energy consumption. Recently, NOAO and the Arizona Game and Fish Department have started a project with GLOBE at Night data and bat telemetry to examine a dark skies corridor in Tucson where the endangered bats fly. In our presentation, results of our efforts are discussed. 333.09 The HST Cycle E/PO Grant Program: Program Highlights Bonnie Eisenhamer1, L. Knisely1, H. Ryer1 1STScI. 8:00 AM - 7:00 PM America Ballroom Foyer The spirit of the HST Cycle E/PO Grant Program is to encourage collaborative efforts between professional astronomers/space scientists and professional educators that would broaden the knowledge and understanding of the latest discoveries of the Hubble Space Telescope. HST Cycle E/PO grants provide NASA funding for HST Principal Investigators and Hubble Fellows to develop and implement small E/PO projects based upon the science and/or science theme of the parent research program(s). Awardees do this working in partnership with professionals in the education and outreach communities. Beginning with Cycle 8, 170 science programs have been represented in the HST Cycle E/PO Grant Program. This poster will feature examples of key E/PO projects funded by the HST Cycle E/PO Grant Program, highlighting the aspects that made each one successful. 333.10 Astronomy Education via The Dynamic Web K. M. Flurchick1, W. Avery1, B. F. Griego2, R. Culver2 1North Carolina A&T State University, 2Colorado State University. 8:00 AM - 7:00 PM America Ballroom Foyer The ability of web applications to provide students the ability to explore and investigate astronomical concepts presented in class in a way which can help student understanding. In this presentation we report on the results of students making use of the computational tools in webMathematicaTM to analyze and investigate a variety of astronomical phenomena, including topics such as the Runge-Lenz vector, descriptions of the orbits of the exo-planets and other topics related to celestial mechanics. Using the exercise described herein, students at the North Carolina A & T State University and Colorado State University investigated via computational simulations the creation and characteristics and the effects of various parameters on these systems being studied. 333.11 Astrobites: The Astro-ph Reader's Digest For Undergraduates Nathan Sanders1, E. R. Newton1, I. Czekala1, K. Rosenfeld1, C. D. Dressing1, D. Gifford2, J. Suresh1, E. Schneider3, C. Morley4, S. Kohler5 1Harvard University, 2University of Michigan, 3University of Arizona, 4UC Santa Cruz, 5UC Boulder. 8:00 AM - 7:00 PM America Ballroom Foyer Do you know an undergraduate embarking on a career in research in astronomy or a related field? Point them to Astrobites, a daily astrophysical literature blog for undergraduates written by graduate students (http://astroph.wordpress.com). Our goal is to present one interesting paper per day in a brief format that is accessible to undergraduate students in the physical sciences who are interested in active research. We not only try to summarize new work, but also to provide valuable context for readers not yet familiar with the astrophysical literature. For example, our posts discuss the long term goals motivating the field, astronomical jargon, and how the technical methods work. Special posts offer career guidance for undergraduates (e.g. how to select a graduate school) and detail personal experiences (e.g. observing at a Chilean telescope or attending a AAS meeting). We present sample Astrobites posts, readership statistics, and the results of our periodic reader surveys from our first semester of blogging (Spring 2011). 333.12 Evidence of Historical Supernovae in Ice Cores Donna Young1 1SAO. 8:00 AM - 7:00 PM America Ballroom Foyer Within the framework of the U.S. Greenland Ice Core Science Project (GISP2), an ice core, known as the GISP H-Core, was collected in June, 1992 adjacent to the GISP2 summit drill site. The project scientists, Gisela A.M. Dreschhoff and Edward J. Zeller, were interested in dating solar proton events with volcanic eruptions. The GISP2-H 122-meter firn and ice core is a record of 415 years of liquid electrical conductivity (LEC) and nitrate concentrations, spanning the years 1992 at the surface through 1577 at the bottom. At the National Ice Core Laboratory in Denver, Colorado, the core (beneath the 12-meter firn) was sliced into 1.5 cm sections and analyzed. The resulting data set consisted of 7,776 individual analyses. The ultrahigh resolution sampling technique resulted in a time resolution of one week near the surface and one month at depth. The liquid electrical conductivity (LEC) sequence contains signals from a number of known volcanic eruptions and provides a dating system at specific locations along the core. The terrestrial and solar background nitrate records show seasonal and annual variations, respectively. However, major nitrate anomalies within the record do not correspond to any known terrestrial or solar events. There is evidence that these nitrate anomalies could be a record of supernovae events. Cosmic X-rays ionize atmospheric nitrogen, producing excess nitrate that is then deposited in the Polar Regions. The GISP2-H ice core has revealed nitrate anomalies at the times of the Tycho and Kepler supernovae. The Cassiopeia A supernova event may be documented in the core as well. We have developed a classroom activity for high school and college students, in which they examine several lines of evidence in the Greenland ice core, discriminating among nearby and mid-latitude volcanic activity, solar proton events, and supernovae. Students infer the date of the Cassiopeia A supernova. 333.13 A Comparison of Online and On-Ground Student Performance in Calculus-based Physics I Andria C. Schwortz1 1Quinsigamond Community College. 8:00 AM - 7:00 PM America Ballroom Foyer The validity and rigor of online courses is an open question in higher education, with each institution applying different interpretations of grades received and making different decisions about whether online courses should be accepted in the transfer process. These discrepancies in institutional opinion are at times based upon the realities of variety in instructional methods or student self-selection into a course they view as an “easy A”, but at times they do a disservice to online classes and students. Quinsigamond Community College, located in Worcester, Massachusetts, is now offering an online section of freshman calculus-based mechanics (General Physics I, PHY 105). During Spring 2011, the author teaches both the online and on-ground sections of the course. Content in the online section is communicated by videos recorded during class sessions in Spring 2010, and both sections perform on-ground labs and take quizzes and exams on-ground. The author is currently studying student outcomes in the two sections to determine the effectiveness of instruction in the different modalities. Preliminary findings will be presented, including analysis of grades in quizzes, online homework (MasteringPhysics), and labs, and comparisons of student problem solving methods and visual representations of problems (such as Free Body Diagrams). The effect of self-selection will also be investigated using open-ended surveys and pretests. Sample size of the two courses consisted of approximately 20 students online and 25 on-ground, with the students commingled into two lab sections of approximately equal size. Support for this project was provided by Quinsigamond Community College. This project received approval by QCC's Institutional Review Board; data presented are either in aggregate form, or are used with informed consent of the participants. 334 Dwarf Galaxies Poster Session America Ballroom Foyer 334.01 A Study of Galaxy Properties in the Overlap Between the Sloan Digital Sky Survey and the Arecibo Legacy Fast ALFA Survey Matthew Dunlap1 1George Mason University. 8:00 AM - 7:00 PM America Ballroom Foyer We present optical long-slit spectra for a sample of low surface brightness galaxies selected either from the Sloan Digital Sky Survey (SDSS) or from the HI 21 cm Arecibo Legacy Fast ALFA (ALFALFA) survey. We use these spectra, combined with optical data from the SDSS and HI data from ALFALFA, to contrast the properties of optically selected low surface brightness galaxies with those selected by their HI emission. In particular, we examine the dark matter fractions and star forming properties of the systems. These spectra are also used to assist in understanding the completeness of the combined ALFALFA and SDSS surveys and our ability to match sources between the surveys. 334.02 Metallicities of RR Lyr Stars in Two Fields of the Small Magellanic Cloud Scott R. Baird1, H. A. Smith2, K. H. Cook3, S. C. Keller4, A. R. Walker5 1Benedictine College and University of Kansas, 2Michigan State University, 3Lawrence Livermore National Laboratories, 4Australian National University, Australia, 5Cerro Tololo Inter-American Observatory, Chile. 8:00 AM - 7:00 PM America Ballroom Foyer Two fields in the central regions of the Small Magellanic Cloud have had the metallicities of their RR Lyr stars determined using Caby photometry. The first field, Field 1, was located at 00h 38m, -73o 08’, with about 17 useful RR Lyr stars, while the second field, Field 3, was located at 01h 02m, -72o 24’with about 13 useful stars. Metallicities were determined for both fields using two different estimates of the reddening, and reddening uncertainty was shown to have little effect on the derived abundances. The best weighted mean values of [Fe/H] were -1.25 + 0.15 for Field 1, -1.23 + 0.19 for Field 3, and -1.24 + 0.11 for the combined fields. The actual spread in the metallicities of the RR Lyr stars in the fields ran from -2.09 to -0.05, significantly larger than the calculated [Fe/H] uncertainties for the individual stars and the standard deviations from the weighted means for the fields. The crowded nature of the fields led to substantial blending difficulties. A subgroup of 9 stars from Field 1 with σ[Fe/H] < 0.30 dex was used as a sample of unblended stars, which gave the weighted mean value of [Fe/H] of -1.38 + 0.20: all stars in this group but one had metallicities between -2.1 and -0.9, and when the single outlier was dropped as a possible unresolved blend the result of [Fe/H] = -1.52 + 0.16 was considered the most reliable. These results indicate a true spread in the metallicities of the RR Lyr stars, suggesting that early in the history of this galaxy there were at least some regions, perhaps very small and localized, perhaps coming from a merger, that had higher than average chemical enrichment. 334.03 The Haverford Variable Star Search project: Segue 2 and Segue 3 Emily Cunningham1, E. Boettcher1, B. Willman1 1Haverford College. 8:00 AM - 7:00 PM America Ballroom Foyer The Haverford Variable Star Search project is being conducted with Kitt Peak National Observatory’s 0.9 meter WIYN telescope. The aims of this project include: to better characterize the population of variable stars in ultra-faint Milky Way companions and tidal streams, to capitalize on RR Lyrae stars’ role as standard candles for those systems, and to search for evidence of extended tidal debris around nearby Milky Way companions. During our first observing run, we obtained B, V, and I time-series observations of the Segue 2 and Segue 3 objects over 2 nights. We present the results of this analysis. We thank NSF AST 0908446 for partial support of this work. 334.04 The Field Star Cluster Population in the Starburst Galaxy NGC 5253 Daniel R. Harbeck1, J. Gallagher III2, D. Crnojevic3 1WIYN Observatory, 2University of Wisconsin, 3IfA, United Kingdom. 8:00 AM - 7:00 PM America Ballroom Foyer NGC 5253 is a dwarf galaxy that currently undergoes a violent central starburst. While the properties of the central starburst have been studied in great detail, the large-scale picture of the starburst in this galaxy remains unstudied. We present a study of star clusters in the field of NGC 5253, based on HST / ACS observations in the F435W, F555W, and F814W bands. While constraint by three-color photometry, we use STARBURST99 models to derive ages and masses for the cluster candidates, and find our observations to be consistent with an episode of star formation about 1 Gyr ago. that was able to produce thee surviving star clusters with masses between 5 to 10 x 10^5 solar masses. We compare the star cluster populations star formation history to the field star population. For the underlying old field stellar populations, we moreover derive photometric metallicity distribution functions via isochrone interpolation and investigate the presence of stellar spatial gradients. Wednesday, May 25, 2011, 8:30 AM - 9:20 AM 300 Demographics in Astronomy and Astrophysics Invited Session America Ballroom 300.01 Demographics in Astronomy and Astrophysics James S. Ulvestad1 1NSF. 8:30 AM - 9:20 AM America Ballroom Astronomy has been undergoing a significant demographic shift over the last several decades, as shown by data presented in the 2000 National Research Council (NRC) report "Federal Funding of Astronomical Research," and the 2010 NRC report, "New Worlds, New Horizons in Astronomy and Astrophysics." For example, the number of advertised postdoctoral positions in astronomy has increased much more rapldly than the number of faculty positions, contributing to a holding pattern of early-career astronomers in multiple postdoctoral positions. This talk will summarize some of the current demographic trends in astronomy, including information about gender and ethnic diversity, and describe some of the possible implications for the future. I thank the members of the Astro2010 Demographics Study Group, as well as numerous white-paper contributors to Astro2010, for providing data and analyses. Wednesday, May 25, 2011, 10:00 AM - 11:30 AM 301 12-Years of Science with Chandra: AGN and SMBHs Meeting-in-a-Meeting America North 301.01 Abstract.Title:It Takes Two to Tango: a Panchromatic View of Merging Black Holes Francesca M. Civano1 1Harvard Smithsonian Center for Astrophysics. 10:00 AM - 10:30 AM America North Double super-massive black holes (SMBHs) within a single galaxy are predicted by hierarchical models of structure formation. Finding these double BHs has been a frustrating search: At z~2, they are hard to resolve, given that the required angular separation is beyond the capability of current ground and space-based observatories. Instead, at later epochs (z<0.7), where the angular separations are larger (~0.5arcsec), they are easier to resolve, but the merger rate has dropped dramatically, so binary SMBHs should be scarce. As mergers proceed, these SMBH pairs will merge. The coalescence give rise to the strongest GW events in the universe. In some cases GW recoil, due to the asymmetric emission of GW, causes the newly merged single SMBH to gain a significant velocity (up to ~1000km/s) with respect to the center of the galaxy. If the recoiling BH is active, it will retain its accretion disk and broad emission line region and will still be seen as an AGN for several years, by which time it may be displaced by several kiloparsecs from the former host nucleus. Deep imaging and spectroscopic searches have recently been initiated to study double SMBHs, or displaced single BH, at all wavelengths and at any separation. I will present multiwavelength results on double SMBHs and show how the high angular resolution of Chandra helps in the study of their activity. I will concentrate on the properties of CID-42 (z=0.359), a unique source in the COSMOS survey, the best recoiling BH candidate to date. CID-42 clearly shows both the presence of two compact sources, ~2.5 kpc apart, embedded in the same galaxy in HST imaging, and a ~1100km/s velocity offset between the narrow and broad components of Hbeta, in three optical spectra. Our new HRC/Chandra data are the key to understanding the nature of this intriguing source. 301.02 Abstract.Title:The AMUSE surveys: Down-sizing in Black Hole Accretion Elena Gallo1 1University of Michigan. 10:30 AM - 11:00 AM America North While the term AGN generally refers to nuclear luminosities exceeding a few per cent of the Eddington-limit, the distinction between active and inactive is ultimately set by our ability to detect and interpret signatures of accretion-powered activity. The aim of the AMUSE surveys is to effectively bridge the gap between AGN and formally inactive galaxies. This is accomplished through snapshot Chandra observations of two distance limited samples of early type galaxies: 100 within the Virgo cluster (AMUSE-Virgo), plus 100 field galaxies (AMUSE-Field). The two samples are unbiased with respect to nuclear properties and span over three order of magnitude in host stellar mass, enabling us to investigate accretion-powered activity from local super-massive black holes, and its possible dependence on the environments, down to the Eddington luminosity for a 10 solar mass object. While, at face value, the active fraction for the Virgo sample increases with host stellar mass, we find evidence for a `down-sizing' effect, that is, low-mass black holes emit relatively closer to their Eddington limit than higher mass objects. A similar trend is now apparent for the field sample, albeit with higher detection rates. During this talk, I will present and compare the latest results from the two surveys, and briefly discuss them in the context of environmental effects. 301.03 Formation and Evolution of Dusty Tori in AGNs Shuang-Nan Zhang1, Y. Liu1 1Institute of High Energy Physics, CAS, China. 11:00 AM - 11:15 AM America North The feedback by active galactic nuclei AGNs) is significant for the formation and evolution of galaxies. It has been realized that the radiative pressure feedback could be an efficient mechanism due to the existence of dust. In this talk, we discuss the effect of anisotropic radiative pressure, which is inevitable if the UV/optical emission arises from an accretion disk. The distribution of dusty gas should be also anisotropic due to the influence of the anisotropic disk radiation, i.e., the dust in the face-on direction of an accretion disk can be blown out relatively more easily, whereas the dust can survive in the edge-on direction. This result can explain the presence of some obscured AGNs with high Eddington ratios and can also quantitatively reproduce the observed decreasing fraction of type 2 AGNs with increasing luminosity; both observational results include Chandra's deep survey observations of AGN. A sequence of AGN formation and evolution is also proposed, within the context of the formation, evolution and exhaustion of the dusty torus. Our model predicts the existence of bright AGNs with dusty tori, but without broad line regions. Finally we discuss the implications of the anisotropic radiation for the calculations of luminosity functions and radiation efficiencies of AGNs. (arXiv:1101.2364, ApJL in press). 301.04 Cosmic Accretion and Galaxy Co-Evolution: Lessons from the Extended Chandra Deep Field South C. Megan Urry1 1Yale Univ.. 11:15 AM - 11:30 AM America North The Chandra deep fields reveal that most cosmic accretion onto supermassive black holes is obscured by gas and dust. The GOODS and MUSYC multiwavelength data show that many X-ray-detected AGN are faint and red (or even undetectable) in the optical but bright in the infrared, as is characteristic of obscured sources. (N.B. The ECDFS is most sensitive to the AGN that constitute the X-ray background, namely, moderate luminosity AGN, with log Lx=43-44, at moderate redshifts, 0.5 0.5. We will summarize the first results from the X-ray follow-up of the SPT cluster survey. 309.04 Baryon content of clusters and groups in the context of hierarchical cosmology Andrey Kravtsov1 1University of Chicago. 3:00 PM - 3:30 PM America North Clusters of galaxies are expected to contain a cosmic mixture of baryons and dark matter. However, it is still not clear to what degree this is so. I will discuss recent observational constraints and theoretical expectations of the baryon fractions in galaxy clusters and groups and the puzzling discrepancies between the two. I will also discuss how stellar and gas fractions of clusters fit within the larger context of stellar fraction-halo mass relation for galaxies. 310 Particle Physics II – High Energy Astrophysics Meeting-in-a-Meeting St. George CD 310.01 Pierre Auger: The Sources and Composition of Cosmic Rays Glennys R. Farrar1 1New York University. 2:00 PM - 2:30 PM St. George CD Determining the sources and composition of UHECRs are intertwined problems which cannot be solved independently of each other. The challenge is increased by the lack of important auxiliary information. For instance the particle interactions which determine the properties of the atmospheric showers are directly constrained by experiment only at much lower energy, and we have only approximate information on Galactic and extragalactic magnetic fields. Progress is being made thanks to detailed observations of large numbers of atmospheric showers of individual UHECRs -- measuring the longitudinal development, muon content, and other properties of the shower -- to constrain both UHE particle physics and the composition of the UHECRs. A complementary approach is looking for anisotropies in arrival directions and for correlations between the arrival directions of UHECRs and potential source catalogs. An overview of results from the Pierre Auger Collaboration will be given. 310.02 High Energy Astronomy with the Fermi Gamma-Ray Space Telescope Charles D. Dermer1 1NRL. 2:30 PM - 3:00 PM St. George CD The Fermi Gamma-ray Space Telescope, launched in 2008, has revolutionized our knowledge of the gamma-ray sky. After briefly summarizing the observing techniques of the Large Area Telescope on Fermi, major results are described. The source catalog made with the first 11 monts of science data contain 1451 sources and several new classes of gamma-ray sources, including millisecond pulsars, starburst galaxies and radio galaxies. This talk will emphasize Galactic and ultra-high energy cosmic rays, particle acceleration in GRBs and blazars, new physics results related to tests of Lorentz invariance violations, and measurements of the intergalactic magnetic field. Implications of bulk outflow Lorentz factors inferred from gamma-gamma opacity arguments will be considered in light of the search for high-energy neutrinos from black-hole jet sources. 310.03 Radio Detection of Ultra High Energy Neutrinos James J. Beatty1 1Ohio State University. 3:00 PM - 3:30 PM St. George CD Ultra high energy cosmic rays interact with the cosmic microwave background radiation, resulting in the production of energetic pions. These interactions result in energy loss by the incident cosmic ray leading to the Greisen-Zatsepin-Kuzmin (GZK) feature in the cosmic ray spectrum at about 4×10^19 eV, and the decay of the charged pions produced in these interactions results in neutrinos known as Berezinskii-Zatsepin (BZ) neutrinos. These neutrinos interact only via the weak interaction, with negligible absorption over cosmic distances but interaction lengths in the Earth of a few hundred kilometers. When these neutrinos interact in a dense medium, the electromagnetic component of the resulting shower develops a negative charge excess due to Compton scattering of the electrons from the medium and depletion of positrons by in-flight annihilation. This macroscopic charge excess moves at nearly the speed of light, and its passage through a dielectric medium results in coherent Cherenkov radiation at radio wavelengths longer than the size of the radiating region. This process is known as the Askaryan mechanism, and has been observed in accelerator experiments. The radio pulse is impulsive, and can be detected over large volumes in materials with long radio attenuation lengths, most notably the cold ice in the Antarctic ice sheet. Upper limits on the neutrino flux obtained by the balloon-borne instrument ANITA are now approaching the expected flux, and prototype in-ice antenna arrays are now being deployed. Prospects for large detectors capable of detecting hundreds of these neutrinos will be discussed. This work is supported by NASA under grants NNX08AC17G and NNX11AC45G, by the NSF under grant PHY-0758082, and by the Ohio State Center for Cosmology and Particle Astrophysics (CCAPP). 311 Astrophysics with Kepler II Meeting-in-a-Meeting America South 311.01 Devil in the Details: Investigating Astrophysical Phenomena with Kepler Light Curves Jon Michael Jenkins1, Kepler SOC, Kepler SO, Kepler Science Team 1SETI Institute. 2:00 PM - 2:15 PM America South The light curves produced by the Kepler photometer are unprecedented in their photometric precision, completeness, and contiguity. Moreover, although Kepler was designed to detect 100 ppm changes in brightness corresponding to transits of Earth-size planets crossing Sun-size stars, the Kepler light curves preserve intrinsic intensity variations across a large dynamic range, including those of RR Lyrae stars, which can increase their brightness by more than a factor of two over a few hours. The large dynamic range and phenomenal photometric precision of Kepler promises to revolutionize the study of intrinsic stellar variability and a wide variety of variable stars on timescales from minutes to several years. In this paper, we describe the science pipeline processing that produces the uncorrected and the systematic error-corrected light curves, and give examples of residual instrumental artifacts that can be found in the data, such as those caused by thermal changes due to the position of the spacecraft with relation to the sun or heaters cycling on and off on various spacecraft components (which can change the shape of the telescope and alter its focus), as well as examples of processing artifacts that can occur. We also describe algorithms in development that promise to improve our ability to identify and remove instrumental signatures and further reduce the incidence of processing artifacts in the archival light curves, thereby increasing the usability of the corrected light curves for astrophysical investigations. Kepler was selected as the 10th mission of the Discovery Program. Funding for this mission is provided by the NASA Science Mission Directorate. 311.02 Understanding Stellar Variability in Kepler Lightcurves Gibor S. Basri1 1UC, Berkeley. 2:15 PM - 2:30 PM America South The Kepler mission is generating an unprecedented set of lightcurves for stars, with the best precision and coverage ever achieved. Not surprisingly, there have been many new phenomena seen. Some of these we think we understand, and some remain mysterious. We present a short sampler of some of these, both as individual cases, and also certain classes of variables. In addition to variability in the stars, there are substantial instrumental effects. We discuss our current understanding and ability to correct for these (which are different from quarter to quarter), and what sorts of stellar variability cannot currently be confidently measured. 311.03 The Kepler Cluster Study Soren Meibom1, Kepler Science Team 1Harvard-Smithsonian,CfA. 2:30 PM - 2:45 PM America South The Kepler Cluster Study is a program to search for transiting planets around members of 4 open star clusters in the Kepler field of view, and to study the dependencies of stellar rotation, differential rotation, and other activity and dynamo related observables, on stellar age and mass. This talk will describe the study and present its first results and near term goals. Kepler was selected as the 10th mission of the Discovery Program. Funding for this mission is provided by NASA, Science Mission Directorate. 311.04 Ages of Old Open Clusters in the Kepler Field from Detached Eclipsing Binaries Eric L. Sandquist1, K. Brogaard2, F. Grundahl2, M. Jeffries1, R. Mathieu3, M. Shetrone4, J. Orosz1, H. Bruntt2, J. V. Clausen5, A. Dotter6, S. Frandsen2, A. Geller7, D. Stello8, D. VandenBerg9, K. Williams10 1San Diego State Univ., 2Aarhus University, Denmark, 3U. Wisconsin, 4McDonald Observatory, 5Copenhagen U., Denmark, 6Space Telescope Science Institute, 7Northwestern Univ., 8University of Sydney, Australia, 9Univ. of Victoria, Canada, 10Texas A&M U.. 2:45 PM - 3:00 PM America South Open clusters in the Kepler field are becoming a test bed for all of the major methods of age determination for stars. We present preliminary results for Kepler observations and supporting ground-based observations of detached eclipsing binaries in the old open clusters NGC 6791 and NGC 6819. The goals of this program are to characterize an ensemble of multiple star systems that can 1) constrain the cluster ages more strongly than any other technique via mass and radius measurements of evolved stars, and 2) precisely determine the masses and radii of stars spanning the cluster color-magnitude diagrams in order to validate model predictions for photometry. We gratefully acknowledge funding from the NSF under grant AST 0908536 (E.S.) and AST-0908082 (R.M.), and NASA under grant NNX11AC76G. 311.05 The Effects of Starspots on Transit Timings for Kepler-9 William F. Welsh1, Kepler Science Team 1San Diego State Univ.. 3:00 PM - 3:15 PM America South The Kepler-9 planetary system contains three transiting planets, two of which have been confirmed via transit timing variations caused by their mutual gravitationally interaction. The host star is active, and the light curve shows starspot modulations that are comparable in size to the depths of the transits. If the planet transits over a starspot it will cause a change in the transit shape, and thus induce a shift in the measured mid-transit time that cannot be removed by simple detrending. We present a study of the effects of the starspots on the transit shapes, and specifically on the measured transit times. 311.06 A First Look at Galaxies with Kepler Michael N. Fanelli1, Kepler Team 1NASA Ames Research Center. 3:15 PM - 3:30 PM America South Kepler is principally an exoplanet and stellar astrophysics experiment. Late-type dwarf stars form the bulk of the ~170K sources in the target list. Although centered at low galactic latitude (13.5°), the continuously monitored field-of-view contains over 11K cataloged galaxies. During the early phase of the mission, a number of galaxies were observed, some serendipitously, and then dropped. Another set of galaxies was explicitly monitored for several observing quarters to assess their viability as “quiescent” photometric and astrometric sources. Normal galaxies are not expected to be variable on the timescales and amplitudes seen in stellar sources, and are not subject to centroid motions due to parallax, proper motion or binarity. We describe the light curves of the observed galaxies, their observed photometric and astrometric precision, and the potential for identifying variability due to active nuclei and episodic events. These data provide a first look at normal galaxies surveyed with Kepler, and complement observations of the few known active galaxies in the field. 312 The Panchromatic View of Star Formation and Protoplanetary Disks in Diverse Environments II Meeting-in-a-Meeting America Central 312.01 Star Formation and the Dynamical Evolution of Young Clusters Nicholas James Wright1 1Harvard-Smithsonian Center for Astrophysics. 2:00 PM - 2:22 PM America Central Dynamical evolution plays a key role in shaping the observable properties of star clusters and stellar associations. Observable properties such as mass segregation, clustering, and runaway stars are all products of complex N-body interactions in large stellar systems. I will discuss the implications for star cluster research of dynamical evolution, as well recent results and upcoming possibilities through missions such as GAIA. 312.02 Observations and theory on the externally induced photoevaporation of circumstellar disk Mario G. Guarcello1 1Harvard-Smithsonian CfA. 2:22 PM - 2:44 PM America Central Class II Pre-Main Sequence stars are characterized by the presence of the circumstellar disk in the equatorial plane, which is the site of the planets formation. The induced photoevaporation of disks is one of the key processes leading the evolution of these structures. Photoevaporation occurs when the disk is irradiated by UV and X-ray radiation: Far UltraViolet (FUV) photons (with energy ranging from 6eV to 13.6eV) dissociate H2 molecules, while Extreme UltraViolet (EUV, from 13.6eV to 100eV ) and X-ray photons ionize gas atoms. Since both processes heat the gas up to 1000K-10000K, the thermal pressure drives a photoevaporative flow of gas away from the disk. Photoevaporation is usually induced by the central star itself; however, direct images (taken with the Hubble Space Telescope) of the young stars surrounded by photoevaporating disks in the Orion Nebula Cluster showed that photoevaporation can be induced by the energetic radiation emitted by nearby massive stars. In these cases, the externally induced photoevaporation can dissipate the disks in short timescale (even smaller than 1 Myear in the more extreme situations). Besides, recent studies of the massive young clusters NGC2244 and NGC6611 confirmed that the evolution of circumstellar disks is affected by induced photoevaporation in the core of such massive clusters, but there is still some controversy about these results. In this talk I will review the main features of the photoevaporation process, its effects on disks evolution when it is induced by nearby ionizing sources, and the supporting observational evidences. 312.03 Protoplanetary disk chemistry Karin Oberg1 1Harvard-Smithsonian CfA. 2:44 PM - 3:06 PM America Central The accretion disks around pre-main-sequence stars provide the raw material and initial conditions for the formation of planetary systems. Disk chemistry is thus essential to predict the composition of planetesimals and eventually planets - comet compositions in our own solar system reveal that efficient astrophysical pathways to chemical complexity exists. The chemical evolution is predicted to depend on radiation fields, temperature and density structures. This can be exploited to develop molecular probes of otherwise inaccessible disk processes, and protoplanetary disk chemistry studies typically have the combined objective of constraining how the disk physics drives the disk chemistry, and how the disk chemistry traces the disk physics. Observationally, disk chemistry has been characterized by infrared spectroscopy of the innermost few AUs, far-infrared spectroscopy of the disk atmosphere, and millimeter spectroscopy of the outer disk. This has revealed strong emission from a range of common molecules and ions such as CO, CN, HCN, C2H2, H2O, OH, H2CO, HCO+, N2H+ and DCO+. As expected some lines are found to follow trends with respect to quiescent stellar heating, mass accretion rates, X-ray ionization, and the disk density structure. In response to these observations and in anticipation of more detailed data from especially ALMA, the physical-chemical modeling and theory of disks is the subject of intense efforts. A range of different model approaches have been developed that vary in their treatment of disk structure, radiation fields, and chemical networks. The results stress the importance of UV and X-ray fields as well as the treatment of grain surface chemistry and its relation to gas-phase processes. These recent advances in observations and models of disk chemistry will be reviewed together with current challenges, and the next generation of models, laboratory experiments and observations that will address them. 312.04 Protoplanetary disks to planets Catherine Espaillat1 1Harvard-Smithsonian Center for Astrophysics. 3:06 PM - 3:28 PM America Central In their initial stages of formation planets should interact with the accretion disk surrounding the newborn star, clearing the material around themselves and leaving behind an observational signature in the form of clearings in the disk. Stars with inner holes in their disks have been detected and are labeled as transitional objects. A few years ago, Spitzer identified a new class of "pre-transitional disks" which have gaps rather than holes - they have an inner disk, a gap, and an outer disk. In several cases, millimeter imaging has confirmed the cavities in (pre-)transitional disks previously inferred from SED modeling. Infrared variability has also been found to be a common phenomenon in such objects. Physical mechanisms that have been presented to explain disk clearing can be tested with these observations; forming planets emerge as the most likely explanation. 313 The Oort Cloud: How is it Filled? How is it Emptied? Special Session St. George AB 313.01 A Jovian Mass Object in the Oort Cloud? Jack J. Lissauer1, J. J. Matese2, D. P. Whitmire2 1NASA Ames Research Center, 2University of Louisiana. 2:05 PM - 2:30 PM St. George AB We discuss an updated dynamical and statistical analysis of cometary evidence suggesting that the Sun may have a Jovian mass companion orbiting in the outer regions of the Oort comet cloud. Such a companion could also have produced the detached Kuiper Belt object Sedna. If the object exists, evidence for it likely resides in the data collected by the recently completed Wide-field Infrared Survey Explorer (WISE) mission. 313.02 WISE and the Oort Cloud Edward L. Wright1 1UC, Los Angeles. 2:30 PM - 2:55 PM St. George AB Even at the inner edge of the Kuiper Belt, objects are too cold for WISE to see their thermal emission. Thus WISE is limited to reflected Sunlight, and this is brighter in the optical than at 3.4 microns. Hence WISE is only efficient for finding gas giants in the Oort cloud, with mass greater than Jupiter, whose internal heat produces a large flux at 4.6 microns. For Jupiter itself, DIRBE measured 6 kJy at 4.9 microns. Since the W2 band is more centered on the peak of the spectrum, WISE could see this at a distance 10000 times greater than the actual distance of Jupiter, or nearly one light-year. But if Jupiter were this far from the Sun, its bolometric flux would go down by nearly a factor of two, and the W2 flux would go down by a larger but model dependent factor. Thus WISE should be able to barely pick up the 1 Jupiter mass object at a distance of 30,000 AU that is at one corner of the Matese and Whitmire parameter space. But such an object would only be one source among thousands of band 2 only sources at the 5 sigma limit. Finding this needle in a haystack will require a reprocessing and co-addition of the post-cryogen data collected by WISE, an effort which is currently not funded by NASA. 313.03 Galalctic Tides & the Sinusoidal Potential David F. Bartlett1 1Univ. of Colorado. 2:55 PM - 3:30 PM St. George AB The sinusoidal potential is a nonNewtonian alternative to dark matter. Instead of φ = -GM/r we write φ = -(GM/r) cos kor, where ko= 2π/ λo and λo = Ro/20= 400 pc. Evidence for this choice for the “wavelength” λo has been given in one article and many previous meetings of the AAS & DDA. The solar system and nearby stars are trapped in a local groove of width Δr < 400 pc. The rapid alternation of attraction and repulsion within the groove gives very strong Galactic radial tides. The epicyclic period is only 7 Myr . The Keplerian period for comets in the middle of the Oort cloud is also 7 Myr. The 1:1 resonance between material in the groove and the cloud provides a new mechanism for filling the Oort cloud. The Oort cloud is emptied by the same strong radial tides. Evidence is found in the 499 comets with calculated 1/aoriginal in the latest Catalogue of Cometary Orbits (Marsden & Williams 2008). . I separate the comets into 12 classes on the basis of Quality (4 types) and semi-major axis aoriginal . For 10 of the 12 classes radial tides dominate Z-tides. The classic Oort cloud comets (1851-1996) have a particularly strong modulation with galactic longitude. This modulation is exactly in those directions where a radial tide would be important. The equally numerous recent Oort comets (1996-2008) show a different evidence for strong radial tides. The recent comets generally have much larger perihelion distances q than the classic ones. Here the evidence is that a radial tide is removing angular momentum from the orbit and thus bringing the perihelion closer to the earth and to observers. 314 SPICA and the Promise of the Far-Infrared Special Session Gloucester 314.01 SPICA: The Space Infrared Telescope for Cosmology and Astrophysics Takao Nakagawa1 1Institute of Space and Astronautical Science, Japan. 2:00 PM - 2:30 PM Gloucester We are presenting an overview of the SPICA (Space Infrared Telescope for Cosmology and Astrophysics) mission, which is a mission optimized for mid- and far-infrared astronomy with a cryogenically cooled 3-m class (3.2 m in the current design) telescope. Its high spatial resolution and unprecedented sensitivity in the mid- and far-infrared will enable us to address a number of key problems in present-day astronomy, ranging from the star-formation history of the universe to the formation of planets. To reduce the mass of the whole mission, SPICA will be launched at ambient temperature and cooled down on orbit by mechanical coolers on board with an efficient radiative cooling system. This combination allows us to have a 3-m class cooled (6 K) telescope in space with moderate total weight (3.7t). SPICA is proposed as a Japanese-led mission together with extensive international collaboration. ESA is a major partner and is supposed to take responsibility for the SPICA telescope assembly, a European ground segment, an European instrument systems engineering and management. The assessment study on the European contribution to the SPICA mission has been conducted under the framework of the ESA Cosmic Vision 2015-2025. US community also shows strong interest to participate in SPICA and to procure a sensitive far-infrared and sub-mm spectrometer. Assessment study of this type of spectrometers was conducted with NASA funding in 2010. Korean participation is also being discussed extensively. The target launch year of SPICA is late 2010s. 314.02 Far-IR Emission Lines from High-Redshift Cooling J. Michael Shull1 1Univ. of Colorado. 2:30 PM - 3:00 PM Gloucester Formation of the first stars and galaxies is initiated by radiative cooling of primordial gas clouds (Population III) and metal-contaminated gas (Population II) in dark-matter halos. The primary coolants are hydrogen (H I, H2, HD) and fine-structure transitions from [C II], [O I], [Si II], [Fe II], the heavy elements formed by nucleosynthesis in early massive stars and supernovae. Enriched by the first stars, metal lines control the high-redshift transition from Pop III to Pop II, once the metallicity rises above a critical value of approximately Z_crit = 0.0003 Z_solar. Direct emission-line detection would quantify the cooling that governs the transition in stellar initial mass function. Because early nucleosynthesis may be biased toward alpha-process (O, Si) and Fe-group elements, the fine-structure line ratios may not reflect solar abundances. Current models of primordial cooling suggest that line-detection sensitivities (BLISS, ALMA) could approach values, 10^-20 W / m^2, at which large cooling gas clouds could be seen. Limits on the integrated backgrounds at wavelengths of [C II] (157.74 microns), [O I] (63.18, 145.5 microns), [Si II] (34.8 microns); [Fe II] (25.99, 35.35 microns) redshifted into the far-IR and sub-mm, could constrain the high-redshift radiative cooling rates associated with early galaxies. 314.03 The Evolution of the Interstellar Medium as Traced by Mid and Far-IR Spectroscopy Gordon Stacey1 1Cornell. 3:00 PM - 3:30 PM Gloucester I will discuss how the mid and far-infrared fine structure lines of abundant atoms and ions can be used to trace the evolution of the interstellar medium in galaxies from earliest times to the present. These lines are of particular interest as they are both easily excited and suffer relatively little from extinction by dust. I plan a review of the current state of knowledge, followed by a discussion of the new science that will be enabled with the advent of SPICA and ALMA. 315 Using the Discoveries of Astronomy to Teach Physics Special Session Staffordshire 315.01 Using Cosmology to Teach Physics Max Tegmark1 1MIT. 2:00 PM - 2:20 PM Staffordshire I describe why I think cosmology is an excellent tool for teaching physics. 315.02 Using Exoplanets to Engage Students in Physics David Charbonneau1 1Harvard University. 2:20 PM - 2:40 PM Staffordshire A hundred planets transiting bright stars are now known, ensuring that at any particular site at least one transit is visible on any given night. Most of these worlds were discovered with 4-inch telescopes, and so the modest telescopes that nest atop the physics buildings of many college campuses are more than adequate to pursue the transit events. Fueled by results from the NASA Kepler Mission and the promise of Earth-like worlds, exoplanets offer an enormous opportunity to engage first-year college students in physics. The simple geometric nature of these systems permits the direct application of introductory mechanics to deduce the basic properties of some planets orbiting other stars. Moreover, by gathering and analyzing their own data, students can understand the fundamentals of experimental science and data analysis. I will discuss the opportunities to engage students in physics through transiting exoplanets, with specific examples drawn from a first-year undergraduate course at Harvard University. I will also review the practical aspects, including software and hardware, of establishing an exoplanet observing lab appropriate for college students. 315.03 A Calculus-Level Introductory Physics Course with an Astronomy Theme Joseph Amato1 1Colgate University. 2:40 PM - 3:00 PM Staffordshire Physics from Planet Earth (PPE) is a one-semester, calculus-based introductory course in classical mechanics intended for first year students of physics, chemistry, astronomy and engineering. Most of the core topics in mechanics are included, but many of the examples and applications are drawn from astronomy, space science, and astrophysics. The laws of physics are assigned the task of exploring the heavens - the same task addressed by Newton over 300 years ago at the birth of classical mechanics. How do we know the distance to the Moon, Sun, or other galaxies? How do we know the masses of the Earth, Sun, and other planets and stars, and why do we believe in “missing” mass? As a physics course, PPE concentrates on how we know rather than what we know. Examples and applications include those of historical importance (the Earth-Moon distance, the Earth-Sun distance, Ptolemaic vs. Copernican models, weighing the Earth) as well as those of contemporary interest (Hubble’s Law, rocket propulsion, spacecraft gravity boosts, the Roche limit, search for extrasolar planets, orbital mechanics, pulsars, galactic rotation curves). The course has been taught successfully at Colgate for over a decade, using materials that have been developed and refined during the past 15 years. Developers of PPE are eager to enrich the course by identifying other topics in contemporary astronomy that can be adapted for the first year physics audience. 315.04 Using Planetary Nebulae to Teach Physics Karen B. Kwitter1 1Williams College. 3:00 PM - 3:10 PM Staffordshire We have developed an interactive website, "Gallery of Planetary Nebula Spectra," (www.williams.edu/Astronomy/research/PN/nebulae/) that contains high-quality optical-to-near-infrared spectra, atlas information, and bibliographic references for more than 160 planetary nebulae that we have observed in the Milky Way Galaxy. To make the material more accessible to students, I have created three undergraduate-level exercises that explore physics-related aspects of planetary nebulae. “Emission Lines and Central Star Temperature” uses the presence or absence of emission lines from species with different ionization potentials to rank the temperatures of the exciting stars in a selection of nebulae. “Interstellar Reddening” uses the observed Balmer decrement in a sample of planetary nebulae at different Galactic latitudes to infer the distribution of interstellar dust in the Milky Way. Finally, “Determining the Gas Density in Planetary Nebulae,” which I will focus on here, uses the observed intensity ratio of the 6717 Å and 6731 Å emission lines from singly ionized sulfur to determine the electron density in the nebular gas. These exercises demonstrate that planetary nebula spectra are useful real-world examples illustrating a variety of physical principles, including the behavior of blackbodies, wavelength-dependent particle scattering, recombination-line ratios, atomic physics, and statistical mechanics. 315.05 Lessons from Outreach: What works; what doesn’t Philip M. Sadler1 1Harvard-Smithsonian, CfA. 3:10 PM - 3:20 PM Staffordshire Outreach to teachers in the form of professional development can help to inform college instructors as to the effectiveness of methods aimed at increasing subject matter and pedagogical content knowledge. College faculty employ a wide range of activities in summer institute programs, often in all-day, residential programs. Comparing such immersion experiences can tell us quite a bit about learning using a variety of systematic approaches to teaching physics and astronomy under ideal conditions. 315.06 Excitement, Instruction, Engagement, and Learning Chris David Impey1 1Univ. of Arizona. 3:20 PM - 3:30 PM Staffordshire The universe is the largest and most impressive possible arena for the exploration of physical principles. Educational research shows that the act of learning requires active engagement rather than passive transmission of information. Modern astronomy provides several unique advantages for the teaching of physics. It shows a small set of physical laws operating over a wide range of scales in very different cosmic contexts. It is driven by very rapid research advances and iconic telescopes and space missions. It is connected to a pervasive desire to understand our place in the universe. Although study of the universe is not like lab science, it illustrates the strengths and limitations of the scientific method. This talk will cover the best pedagogical practice for teaching astronomy and physics, and give examples of topics that provide the potential for a rich learning experience. Wednesday, May 25, 2011, 3:40 PM - 4:30 PM 316 What Drives the Growth of Black Holes? Invited Session America Ballroom 316.01 What Drives the Growth of Black Holes? Ryan C. Hickox1 1Durham University, United Kingdom. 3:40 PM - 4:30 PM America Ballroom Supermassive black holes are amazingly exotic and yet ubiquitous objects, residing in the centers of essentially all stellar bulges in galaxies. Recent years have seen remarkable advances in our understanding of how these black holes form and grow over cosmic time, and how energy released by active galactic nuclei connects the growth of black holes to their host galaxies and large-scale structures. I will review a few recent observational and theoretical studies that explore AGN activity over a wide range of scales, from the inner accretion flow to the outer regions of galaxy clusters, and using a variety of techniques from observations of individual objects to simulations of whole cosmological volumes. Together, these studies are leading us toward a remarkably detailed picture of how black holes grow and influence their surroundings, and show that black holes have an important (and perhaps unexpected) role to play in history of the Universe. Wednesday, May 25, 2011, 4:30 PM - 6:00 PM 317 AGN, Mergers, and Jets Oral Session America North 317.01 Investigating The Agn - Merger Connection At Z~2 With CANDELS Dale Kocevski1, M. Mozena1, A. M. Koekemoer1, J. R. Trump1, N. A. Grogin2, D. C. Koo1, K. Nandra3, S. M. Faber1, CANDELS Collaboration 1University of California, Santa Cruz, 2Space Telescope Science Institute, 3Max Planck Institute for Extraterrestrial Physics. 4:30 PM - 4:40 PM America North Using high-resolution HST/WFC3 imaging in the J and H bands, we have examined the rest-frame optical morphologies and colors of X-ray selected AGN hosts at z~2 for the first time. This imaging was taken as part of the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS), which aims to document the evolution of galaxies and black holes at z > 1.5. I will show that from visual classifications we have determined that AGN hosts do not exhibit merger or interaction signatures more often than non-active galaxies of similar mass at this redshift. We have also used Galfit to determine the morphological breakup of these galaxies and find that a high fraction of the AGN are located in disk-like systems. Our results suggest that the bulk of the X-ray luminous AGN population at z~2 could not have been triggered by a major merger event in the recent past. I will compare the observed properties of the AGN hosts to what is predicted from semi-analytic cosmological models which incorporate a prescription for merger-triggered, self-regulated black hole growth and discuss the implications for AGN feedback models. 317.02 Space Densities Of AGN And The FR Dichotomy Melanie Gendre1, J. V. Wall2, P. N. Best3 1JBCA, United Kingdom, 2UBC, Canada, 3ROE, United Kingdom. 4:40 PM - 4:50 PM America North Extended double-lobe radio sources can be morphologically classified into two groups: Fanaroff-Riley (FR) type I sources have the highest surface brightness along the jets near the core and FR type II sources show the highest surface brightness at the lobe extremities, as well as more collimated jets. This work focuses on a comparison of the space densities of FRI and FRII sources at different epochs, with a particular focus on FRI sources. The Combined NVSS-FIRST Galaxy catalogue (CoNFIG), a sample of radio sources at 1.4 GHz, includes VLA observations, FRI/FRII morphology classifications, optical identifications and redshift estimates. The final catalogue consists of 858 sources over 4 samples (CoNFIG-1, 2, 3 and 4 with flux density limits of S_1.4GHz = 1.3, 0.8, 0.2 and 0.05 Jy respectively). It is 95.7% complete in radio morphology classification and 74.3% of the sources have redshift data. Combining CoNFIG with complementary samples, the distribution and cosmic evolution of FRI and FRII sources are investigated. It is found that FRI sources undergo mild evolution and that, at the same radio luminosity, FRI and FRII sources show similar space density enhancements in various redshift ranges, implying a common mechanism powering the luminosity-dependent evolution. This improved understanding of radio galaxy evolution will also give better insight into the the physics of AGN and their role in galaxy formation. 317.03 Large scale Extragalactic Jets In The Chandra Era Francesco Massaro1, D. Harris1, C. Cheung2 1Smithsonian Astrophysical Observatory, 2National Radio Astronomy Observatory. 4:50 PM - 5:00 PM America North We report initial results from a systematic investigation of the properties of large-scale AGN jets detected in X-rays. We have uniformly analyzed archival Chandra data for more than 90 such sources and measure fluxes in three X-ray bands to estimate spectra. We discuss the sample, the reduction methods, and present first results for the ratio of X-ray to radio flux and the spectral analysis for jet knots and hotspots. Utilizing archival VLA and MERLIN data, we examine the X-ray and radio properties for the jet knots and hotspots in the sample which includes quasars and low- and high-power (FR1 and FR2) radio galaxies. As two different processes have been proposed for the X-ray emission mechanism -- synchrotron and inverse Compton -- we discuss on a possible new classification scheme for extragalactic jets based on our data. From our comparison of their radio-to-X-ray properties, several aspects on their nature became unexpectedly unclear, as different emission processes seems to provide no differences in the observable quantities. 317.04 Black Hole Spin and Radio Loud/Quiet Dichotomy of Active Galactic Nuclei Alexander Tchekhovskoy1, R. Narayan2, J. C. McKinney3 1Princeton University, 2Harvard University, 3Stanford University. 5:00 PM - 5:10 PM America North Radio loud active galactic nuclei are on average 1000 times brighter in the radio band than radio quiet ones. We investigate whether this radio loud/quiet dichotomy can be due to differences in the spin of central black holes (BHs) that power the radio emitting jets. We construct steady state axisymmetric numerical models for a wide range of BH spin, a. We assume that the magnetic flux that threads the BH is held constant. For a BH surrounded by a thin accretion disk, we find that the conventional expression for BH power, P ~ a^2, is accurate to within a factor of a few. We conclude that in this scenario differences in spin can account for power variations of at most a few tens. However, if the disk is thick, the power variation becomes much steeper, P ~ a^4 or even ~a^6. Power variations of 1000 are then possible for realistic BH spin distributions. We derive an analytic solution that accurately reproduces the steeper scaling of jet power with spin. 318 Dust and Star Formation Oral Session America Central 318.01 Spectroscopic Detection of Carbon Monoxide Fundamental Band in the Cassiopeia A Supernova Remnant Jeonghee Rho1, T. Onaka2, J. Cami3, W. Reach4 1SOFIA Science Center/USRA/NASA Ames Research Center, 2University of Tokyo, Japan, 3University of Western Ontario, Canada, 4SOFIA Science Center/USRA. 4:30 PM - 4:40 PM America Central We report spectroscopic detection of carbon monoxide at 4.5 micron fundamental band from the young supernova remnant Cassiopeia A (Cas A). AKARI Infrared Camera (IRC) observations were made towards 4 positions where narrow-filter CO image at 2.29 micron infers plausible detection of CO molecules. Our IRC spectroscopy unambiguously revealed broad features of CO fundamental bands. The CO emission is detected from all of four positions which include northern shell and Minkowski knot and central unshocked ejecta. The spectra show two main peaks, but peaks vary position to position. We can reproduce the observed emission with optically thin CO emission at temperatures between 1500 and 2500 K and at radial velocities of -2000 km/s. We will present comparison of CO in Cas A with that detected in supernovae. Our observations address importance of molecule formation and Type II supernovae are indeed factories of molecules in early Universe. We will discuss CO formation processes and mass of CO, degree of CO destruction in ejecta, implication of mixing, evolution of carbon dust, molecule and dust formation in early Universe. Future SOFIA FLITECAM and FORCAST grism instruments cover near- and mid-infrared wavelengths with a high resolution spectroscopy and will allow us to advance our understanding of molecule and dust evolution in galaxies and the Milky Way. 318.02 How Are Magnetic Fields Being Traced By Dust? Testing Grain Alignment Theory Using GPIPS Katherine Jameson1, D. P. Clemens2, R. Marchwinski2, M. Pavel2, A. Pinnick2 1University of Maryland, 2Boston University. 4:40 PM - 4:50 PM America Central The role magnetic fields play in star formation is not well understood, and it is possible that magnetic fields may play a critical role. Polarimetry, by tracing the dust grains aligned with the magnetic field, can probe the magnetic field in the clouds where star formation is occurring. Currently, the details of the process that aligns dust grains are still unknown. An understanding of the alignment mechanism is necessary to interpret polarization maps as potential tracers of the Galactic magnetic field. We present results of a study of near-infrared polarimetry of two large molecular clouds using data from the Galactic Plane Infrared Polarization Survey (GPIPS). GPIPS is a 76 sq. degree survey of the Galactic plane that uses the Mimir instrument on the 1.8m Perkins telescope outside Flagstaff, AZ. Recent evidence suggests that radiative torques (RATs) may be the dominant alignment mechanism in molecular clouds. If true, this would mean that the largest dust grains within dense regions of molecular clouds, the regions where the first stages of star formation occur, could be aligned and tracing the local magnetic field. By seeing how percentage polarization changes with increasing depth into dense regions of molecular clouds, we are able to test the predictions of the RATs theory. We also gain valuable insight about how deeply into clouds the magnetic field can be traced and also learn about the grain size distributions there. This work is partially supported by NSF AST 09-07790. 318.03 Recalibrating SFD Using SDSS Spectroscopy And Photometry Eddie Schlafly1, D. P. Finkbeiner1 1Harvard. 4:50 PM - 5:00 PM America Central We use new measurements of reddening using SDSS photometry and spectroscopy to test the SFD dust map. We find that both the photometric and spectroscopic technique agree on a common SFD calibration that is different from the original SFD calibration by 13%. We find additionally that a Fitzpatrick 1999 reddening law provides a good fit to the reddening law derived from these techniques, while CCM and O'Donnell reddening laws are disfavored. 318.04 Optical Properties of Astronomical Silicates with Infrared Techniques Giuseppe Cataldo1, S. A. Rinehart2, D. Benford2, E. Dwek2, R. E. Kinzer3, J. Nuth2, R. Silverberg2, E. Wollack2 1NASA GSFC/USRA, 2NASA GSFC, 3NASA GSFC/ORAU. 5:00 PM - 5:10 PM America Central Infrared observations are uniquely able to observe the astrophysical processes deep within dusty regions and to provide key information on the characteristics of the dust itself. This information is critical for learning the role of dust in gas physics, for exploring how dust processing occurs, and for understanding the formation and destruction mechanisms of dust grains. Though relevant astronomical and ground-based observations already exist, the properties of dust at these long wavelengths are poorly known, and since observed spectral features of dust are used to infer characteristics of the surrounding neighborhood, these large uncertainties lead to ambiguity in interpretation. The OPASI-T program addresses the need for high fidelity optical characterization data in the far and mid infrared, aiming at the creation of a unique library of the optical properties of metal-enriched silicate condensates. Such database will cover a wide wavelength range connecting numerical data with laboratory and astronomical spectra in the mid infrared, while providing new data in the unexplored far-infrared and millimeter regime. Both new and established experiments are used to measure the transmission and reflection properties of amorphous silicates across the infrared, which are then analyzed by way of numerical methods in order to determine the variations of their optical constants and complex dielectric function as a function of wavelength. I will present room-temperature measurements of SiO in a KBr matrix from 5 to 25 μm and its optical properties as derived from a least-squares nonlinear fit applied to a mixed approach coupling the Maxwell-Garnett theory, the Lorentz dispersive model for mixtures, and the averaged equation for transmission. This material is based upon work supported by NASA through the ROSES/APRA program. This research was supported by an appointment (Cataldo) at the Goddard Space Flight Center administered by Universities Space Research Association through a contract with NASA. 318.05 New H- Photodetachment and Radiative Attachment Computations for Astrophysical Environments Hossein Sadeghpour1, P. C. Stancil2, B. M. McLaughlin3, A. Dalgarno1, R. C. forrey4 1Harvard-Smithsonian Center for Astrophysics, 2University of Georgia, 3Queen's University Belfast,, Ireland, 4Penn State University, Berks Campus. 5:10 PM - 5:20 PM America Central We combine new accurate calculations, asymptotic relations, and available experimental data to construct an H- photodetachment cross section reliable for a large range of photon energies. In particular, account is taken of the series of auto-detaching shape and Feshbach resonances between 11.97 and 14.35 eV. The accuracy of the cross section is controlled by ensuring that it satisfies all known oscillator strength sum rules including contributions from resonances and double photodetachment. From the resulting recommended cross section, spontaneous and stimulated radiative attachment rate coefficients are obtained. Photodetachment rates are also computed for the standard interstellar radiation field, in diffuse and dense interstellar clouds, for blackbody radiation, and due to distortion photons in the recombination era. Implications of the new rate coefficients and photo-rates are discussed for a variety astrophysical environments. The work of BMMcL and RCF was supported by a research development grant from Pennsylvania State University. PCS acknowledges support from NSF Grant AST-0607733, while AD acknowledges NSF Grant AST-0607532. 318.06 Synthetic Observations of Protostellar Outflows in Radiation-Hydrodynamic Simulations Stella Offner1, E. J. Lee2, A. A. Goodman1, H. G. Arce3 1Harvard-Smithsonian Center for Astrophysics, 2University of Toronto, Canada, 3Yale University. 5:20 PM - 5:30 PM America Central Identifying and characterizing the mass outflows associated with low-mass protostars is challenging since the outflowing gas is deeply embedded and often characterized by velocities comparable to the cloud turbulence. In order to investigate the evolution of such outflows, we use self-gravitating, radiation-hydrodynamic simulations performed with the Adaptive Mesh Refinement code, Orion. We construct synthetic observations in 12CO in order to compare with recent observations and assess the effects of beam resolution and outflow orientation on inferred outflow properties. We find that the interaction between the outflows and the turbulent core envelopes produces significant asymmetry. In addition, the opening angle broadening with time in both the simulations and CO synthetic observations is similar to that of observed outflows. 318.07 The Enigmatic Dense Core L1451-mm: A First Hydrostatic Core Candidate Jaime E. Pineda1, A. A. Goodman2, H. G. Arce3, S. Schnee4, T. Bourke2, J. Foster5, T. Robitaille2, J. Tanner3, J. Kauffmann6, M. Tafalla7, P. Caselli8, G. Anglada9 1University of Manchester, United Kingdom, 2Harvard University, 3Yale University, 4NRAO, 5Boston University, 6JPL, 7OAN, Spain, 8University of Leeds, United Kingdom, 9IAC-CSIC, Spain. 5:30 PM - 5:40 PM America Central We present the detection of a dust continuum source at 93GHz (CARMA) and 230GHz (SMA), and 12CO(2-1) emission (SMA) towards the L1451-mm dense core located in the Perseus Cloud. These detections suggest a compact object and an outflow where no point source is detected using Spitzer. An upper limit for the dense core bolometric luminosity of 0.07Lsun is obtained. We simultaneously model the broadband SED and the continuum visibilities, and the modeling confirms that a central source of heating is needed to explain the observations. It also shows that the data can be well fitted by a dense core with a YSO and disk, or by a dense core with a central First Hydrostatic Core (FHSC). Unfortunately, we are not able to rule out any of these two models, which produce similar fits. We also detect 12CO(2-1) emission with red- and blue-shifted emission suggesting the presence of a slow and poorly collimated outflow, in opposition to what is usually found towards young objects but in agreement with prediction from simulations of a FHSC. This presents the best candidate, so far, for a FHSC, an object that has been identified in simulations of collapsing dense cores. Whatever the true nature of the central object in L1451-mm, this core presents an excellent laboratory to study the earliest phases of star formation. 318.08 EVLA Continuum Observations of Massive Protostars Peter Hofner1 1New Mexico Tech.. 5:40 PM - 5:50 PM America Central The study of the formation of massive stars throughout the galaxy was enabled by sensitive radiointerferometers likethe VLA, which were instrumental in defining ultra/hypercompact HII region as an early manifestation of newly formed massive stars. At yet younger evolutionary phases we expect emission to be dominated by molecular lines from hot molecular cores with radio continuum emission extremely weak. The availability of the strongly increased continuum sensitivity of the EVLA allows now to begin to observe massive protostars in the radio continuum. Here we present some preliminary results of a large continuum survey which we are presently performing towards a large sample of massive protostars. This research is supported by NSF grant AST-0908901. 319 Galaxy Clusters Oral Session America South 319.01 Mass Profiles and Concentration Parameters for 148 Clusters at z<0.3 Kenneth J. Rines1, M. J. Geller2, A. Diaferio3 1Western Washington University, 2Smithsonian Astrophysical Observatory, 3University of Torino, Italy. 4:30 PM - 4:40 PM America South We combine the CIRS (Cluster Infall Regions in SDSS) sample of 72 clusters at z<0.1 with the HeCS (Hectospec Cluster Survey) sample of 74 clusters in the redshift range 0.1-0.3. Both samples are X-ray flux limited. HeCS contains over 20,000 new redshifts obtained with Hectospec on the MMT. We apply the caustic technique to this full sample of 148 clusters to measure M200 directly and to derive the NFW concentration from the fits of the mass profile to each cluster. We derive the correlation between concentration and mass and its spread at fixed mass and compare these measurements with the expected results from numerical simulations. We also tested the conjecture from some weak lensing studies that cluster concentrations substantially exceed model predictions. This work is supported in part by a Cottrell College Science Award from the Research Corporation. 319.02 The Missing Weak Lensing Mass in Abell 781D Richard Cook1, I. Dell'Antonio1 1Brown University. 4:40 PM - 4:50 PM America South The cluster Abell 781D offers a unique challenge for weak lensing mass measurements. It is situated in the Deep Lens Survey (DLS) field F2 adjacent to 3 other clusters coincident on the sky that make up Abell 781. One of these clusters (Abell 781A) has a nearly identical redshift, X-ray and dynamical mass to Abell 781D. However, Abell 781A is detected with the expected significance in the weak lensing reconstruction, while the significance of the signal at the location of Abell 781D is conspicuously low. We use imaging from OPTIC on WIYN and archival Suprime imaging of this region to reanalyze the weak lensing mass of this cluster. We use these analyses to rule out systematics from the PSF characterization in the DLS map and to show that the source of the discrepancy between the weak lensing derived mass and the masses derived using other proxies is a real effect that requires careful characterization before weak lensing calibration of mass-observable relationships can be fully trusted. 319.03 X-ray Mass Proxies From Hydrodynamic Simulations Of Galaxy Clusters Elena Rasia1 1University of Michigan. 4:50 PM - 5:00 PM America South Using extended sets of cosmological hydro-dynamical simulations of galaxy clusters, we present a detailed study of scaling relations between the total mass and three mass proxies based on X-ray observable quantities: temperature, gas mass, and the product of the two, YX. Our analysis is based on 140 clusters (M_vir > 5e13 Msun/h) with 30 objects having mass larger than 1e15 Msun/h at redshift 0. The large statistics is used to quantify the robustness of the scaling relations, to determine their redshift evolution, and to calibrate their intrinsic scatter and its distribution. We further use another set of 18 objects simulated with 7 different recipes for the physics of the gas to test the robustness of mass proxies against plasma physics. We supplement this intrinsic analysis of simulations, including observational effect expected when measuring the X-ray cluster temperature and gas mass. For this purpose, we create more than 300 events files reproducing Chandra observations and analyze them through the standard X-ray data reduction pipeline. We find that the M-YX relation to be the least sensitive to variations of the ICM physics, its slope, and redshift evolution being always very close to the self-similar prediction. The scatter distribution around the best-fitting relations is always close to log-normal. The gas mass is the mass proxy with smallest scatter, with a mild dependence in redshift. These results confirm that both YX and the gas mass are well suited mass proxies for cosmological applications of future large X-ray surveys. [This work has been partially supported by PRIN-MIUR grant by ASI-AAE and ASI-COFIN; by the INFN-PD51 grant, by HPC-Europa Translational Access program, by DFG Priority Program 1177 and by DFG Cluster of Excellence]. 319.04 Weak Lensing in the Galaxy Cluster Abell 2465 Gary A. Wegner1, C. E. Heymans2 1Dartmouth College, 2University of Edinburgh, Institute for Astronomy, United Kingdom. 5:00 PM - 5:10 PM America South We present a weak lensing analysis of the rare major merger cluster Abell 2465 at z=0.245. Using deep CFHT i-band imaging we reconstruct the mass distribution, resolving the structure in this double cluster. We find the lensing cluster mass estimates to be consistent with the spectroscopic virial mass estimates of the two cluster components with masses of approximately 4 x 10^{14} solar masses. We also compare our lensing reconstruction to the distribution of hot X-ray gas in the region. Optical properties of the cluster are described in Wegner (2011; arXiv:1101.1451). 319.05 Exploring Star Formation in Cluster Galaxies with the Herschel Space Observatory Tim Rawle1, M. Rex1, E. Egami1, S. Chung2, D. Fadda3, Herschel Lensing Survey 1University of Arizona, 2University of Florida, 3NASA Herschel Science Center, CalTech. 5:10 PM - 5:20 PM America South Nominally designed to locate high-redshift galaxies magnified by 44 massive foreground clusters, the ``Herschel Lensing Survey'' (HLS; PI: Egami) also provides deep 5-band, far-infrared (FIR) imaging of the galaxies contained within those clusters. For sources at these redshifts (z~0.2-0.4), Herschel photometry spans the peak of the dust component, allowing us to constrain the dust properties, measure total infrared luminosity and hence derive obscured star formation rate. Although a large fraction of galaxies in massive clusters are quiescent early-types and therefore remain undetected by Herschel, the far-infrared highlights regions of activity within the system. The FIR effectively probes the transitional phases of cluster galaxy evolution, exposing starburst mechanisms such as tidal interactions and mergers, as well as the remnants of the as-yet un-quenched in-fall population. Here we focus on two particular, contrasting clusters at z~0.3: the famous merging system known as the Bullet Cluster, and a relatively undisturbed cluster MS2137. We locate the FIR-bright cluster members and characterize their dust component, allowing us to study the distribution of star formation in the two systems as a function of morphology and local environment. In addition, we investigate an intriguing subpopulation of FIR-luminous galaxies with dust component SEDs that do not conform to the templates derived from local field galaxies, yet are also unlike any sources observed at higher redshift. 320 Pulsars and Neutron Stars Oral Session Staffordshire 320.01 Violation of the Inverse Square Law deduced from a Maximum-Likelihood Analysis of Observational Data on Fluxes and Distances of Radio Pulsars John Singleton1, J. Middleditch2, A. Schmidt2, P. Sengupta3, H. Ardavan4 1National High Magnetic Field Laboratory, 2Los Alamos National Laboratory, 3Nanyang Technological University, Singapore, 4Cambridge University, United Kingdom. 4:30 PM - 4:40 PM Staffordshire We have analyzed pulsar fluxes at 1400 MHz (S1400) and distances (d) extracted from the Parkes Multi-beam Survey using the Maximum Likelihood and other statistical methods. The only assumptions of our analyses are that distribution of pulsar luminosities is distance-independent and that the flux varies as 1/dn, with n an adjustable parameter. If pulsars with singly-peaked pulse profiles, and f0w50 < 0.03, where f0 is the rotational frequency in Hz and w50 is the 50% width in seconds, are selected (comprising some 40% of the Parkes database), their flux is found to diminish with distance as 1/d, rather than as the conventional inverse square law. This result is extremely robust, with the error measure for n = 1 being some six orders of magnitude better than that for n = 2. By contrast, when applied to other astronomical objects, the same analysis techniques return the value n = 2 expected for the inverse-square law. Our result supports a model for pulsars based on the emission of radiation by superluminal polarization currents that has also successfully explained the frequency spectrum of the Crab and 8 other pulsars over 16 orders of magnitude of frequency. This work is supported by US Department of Energy LDRD program. 320.02 Fitting Of Fermi Lat Observations Of Gamma-ray Emitting Pulsars To The Frequency Spectrum Of A Faster-than-light Source Andrea C. Schmidt1, J. Singleton2, H. Ardavan3, J. Middleditch4 1LANL/UNM, 2MPA-NHMFL, 3University of Cambridge, United Kingdom, 4LANL. 4:40 PM - 4:50 PM Staffordshire Recently, we compared multiwavelength observations of nine pulsars with the radiation generated by a polarization current that travels faster than light in a circular orbit, the so-called Superluminal Model for Pulsars (SMP). We found that this single emission process accounts quantitatively for the spectrum of each pulsar over 16-18 orders of magnitude of frequency with minimal adjustable parameters. Here we apply the SMP to observations of gamma-ray emitting pulsars by the Fermi Large Area Telescope (LAT) combined with radio-frequency observations from other instruments. The SMP invokes emission by superluminal (faster than light) polarization currents. In this context, polarization P results from displacement of positive and negative charges in opposite directions; a polarization current occurs when a polarized region moves or changes with time t. If a polarization current oscillates or accelerates, it will emit electromagnetic radiation, just as a current of electrons does. However, unlike electrons, which possess rest mass and are therefore limited to subluminal speeds, polarization currents are moving patterns that may travel arbitrarily fast. While the overall form of the fitted spectra is given by the superluminal nature of the source, their fine structure is influenced by the detailed behavior of the pulsar atmosphere. The two most important parameters are ω, the pulsar's rotational frequency, and Ω, a resonant frequency of the atmosphere around where the emission occurs. It is natural to ascribe the latter to the plasma frequency. All of the pulsars investigated exhibit one further feature; an enhancement of the emission at higher frequencies, which can be attributed to cyclotron resonance of the electrons in the pulsar’s magnetic field. With parameters extracted from the broadband fits, we have calculated values for the number density of electrons and the magnetic field B at the emitting region and derived some systematic properties of these pulsars' plasma atmospheres. 320.03 Discovery of Hottest Superfluid and Superconductor in the Universe Wynn C. G. Ho1, P. S. Shternin2, D. G. Yakovlev2, C. O. Heinke3, D. J. Patnaude4 1University of Southampton, United Kingdom, 2Ioffe Physical Technical Institute, Russian Federation, 3University of Alberta, Canada, 4Smithsonian Astrophysical Observatory. 4:50 PM - 5:00 PM Staffordshire The Cassiopeia A supernova remnant contains a young (about 330-yr-old) neutron star which has a carbon atmosphere and shows a notable decline of the surface temperature. We report a new Chandra observation which confirms the previously reported decline rate. The decline is naturally explained by superconductivity and superfluidity of the protons and neutrons in the stellar core. The protons became superconducting early in the life of the neutron star and suppressed the early cooling rate; thus the neutron star remained hot before the (recent) onset of neutron superfluidity. Once the neutrons became superfluid, the Cooper pair formation process produces a splash of neutrino emission, which accelerates the cooling and results in the observed rapid decline of surface temperature. This scenario puts stringent constraints on poorly-known properties of neutron star cores: on the density dependence of the temperature for the transition to neutron superfluidity, on the early onset of proton superfluidity/superconductivity, and on the reduction factor of the Cooper pair formation process by collective effects in superfluid matter. This represents the first direct evidence for nucleon superfluidity in neutron star cores. 320.04D Estimating the Gamma-ray Pulsar Population with the Fermi-LAT Blind Search Sensitivity Michael Dormody1, Fermi-LAT Collaboration 1UCSC. 5:00 PM - 5:20 PM Staffordshire The number of gamma-ray pulsars discovered in blind frequency searches of Fermi-LAT photon data raises the question of how many pulsars are in our Galaxy, as well as the pulsars' underlying energy and spatial distribution. By using a Galactic pulsar distribution (Faucher-Giguere et al. 2006) and assuming a pulse profile and spectrum similar to those previously detected in blind searches, along with an understanding of the sensitivity of the instrument to blind searches, we can estimate the underlying birth characteristics of pulsars. We present results on this detailed pulsar population study, including estimations of population size and initial spin-down energy distribution. 320.05 Searching For The First "Radio-Quiet" Gamma-ray Emitting Millisecond Pulsar Albert K.H. Kong1, R. H. H. Huang1, P. H. T. Tam1, K. S. Cheng2, J. Takata2, C. Y. Hui3 1National Tsing Hua University, Taiwan, 2University of Hong Kong, Hong Kong, 3Chungnam National University, Korea, Republic of. 5:20 PM - 5:30 PM Staffordshire We report multi-wavelength observations of an unidentified Fermi object in the first-year Fermi catalog. The Fermi source has a candidate X-ray counterpart from Swift and Chandra data. We also identify a possible optical counterpart using the X-ray data. Its X-ray and gamma-ray properties are consistent with known gamma-ray millisecond pulsars. There is a possible X-ray modulation while optical/UV observations indicate that the system is likely in a low-mass X-ray binary system. No known radio source is associated with the proposed counterpart and we suggest that the source is the first "radio-quiet" gamma-ray emitting millisecond pulsar in a low-mass X-ray binary currently in quiescence. This work is supported by the National Science Council of Taiwan. 320.06 On The Cooling Tails Of Thermonuclear X-ray Bursts: News From Terzan 5 Manuel Linares1, D. Chakrabarty1, M. van der Klis2 1MIT, 2University of Amsterdam, Netherlands. 5:30 PM - 5:40 PM Staffordshire The neutron star transient and 11 Hz X-ray pulsar IGR J17480-2446, recently discovered in the globular cluster Terzan 5, showed unprecedented bursting activity during its 2010 October-November outburst. We analyzed all X-ray bursts detected with the Rossi X-ray Timing Explorer and find strong evidence that they all have a thermonuclear origin, despite the fact that many do not show the canonical spectral softening along the decay imprinted on type I X-ray bursts by the cooling of the neutron star photosphere. We show that the persistent-to-burst power ratio is fully consistent with the accretion-to-thermonuclear efficiency ratio along the whole outburst, as is typical for type I X-ray bursts. The burst energy, peak luminosity and daily-averaged spectral profiles all evolve smoothly throughout the outburst, in parallel with the persistent (non-burst) luminosity. We also find that the peak burst to persistent luminosity ratio determines whether or not cooling is present in the bursts from IGR J17480-2446, and argue that the apparent lack of cooling is due to the ``non-cooling'' bursts having both a lower peak temperature and a higher non-burst (persistent) emission. We conclude that the detection of cooling along the decay is a sufficient, but not a necessary condition to identify an X-ray burst as thermonuclear. Finally, we compare these findings with X-ray bursts from other rapidly accreting neutron stars. 320.07 Pulsar Timing Noise: Magnetospheric State Switching or Free Precession? Ian Jones1 1University of Southampton, United Kingdom. 5:40 PM - 5:50 PM Staffordshire Recent radio pulsar observations have demonstrated two interesting phenomena. In some pulsars, smooth variations have been observed in spin-down rate and pulse profile. A precessional interpretation was initially suggested to account for this. In other pulsars, very sharp switches have been observed between different pulse profiles. In the case of at least one pulsar (PSR B1931+24), there is also a sharp change in spin-down rate. This has led to a new model of pulsar variability, based on changes in the magnetosphere rather than on precession. In this talk I will discuss whether or not these two models, precession and magnetospheric state switching, can be reconciled, and examine whether or not the precession hypothesis is still a plausible one in accounting for the smoother timing variations seen in many pulsars. 320.08 Fermi/Gamma-ray Burst Monitor Analysis of SGR J1550-5418 Bursts During an Extreme Outburst in January 2009 Alexander Jonathan Van Der Horst1, C. Kouveliotou2, Y. Kaneko3, E. Gogus3, N. Gorgone4, GBM Magnetar Team 1Universities Space Research Association, 2NASA/MSFC, 3Sabanci University, Turkey, 4Connecticut College. 5:50 PM - 6:00 PM Staffordshire In 2008 October, the Soft Gamma Repeater (SGR) J1550-5418 entered a burst active period that lasted one week. On 2009 January 22, the source entered a second, extremely active period, which lasted for one month, and was followed by a third, small episode in 2009 March. The highest number of bursts from the SGR (~450) was observed on January 22 with the Fermi/Gamma-ray Burst Monitor (GBM). The combination of the unique GBM temporal and spectral capabilities has enabled us to study spectra of most of these SGR bursts in great detail. We present here the results of our time integrated spectral and temporal analysis of all the bursts observed with GBM during the source's active period in January 2009. Further, we compare the properties of these bursts with bursts observed from other SGR sources during extreme activations. 321 Molecular Clouds, HII Regions, Interstellar Medium Oral Session St. George CD 321.01 Galactic Plane Infrared Polarization Survey - First Data Release Dan P. Clemens1, A. Pinnick1, M. Pavel1, J. Moreau1, R. Marchwinski1, M. Bartlett1, B. Taylor1 1Boston Univ.. 4:30 PM - 4:40 PM St. George CD We announce the initial public release of data products from the ongoing Galactic Plane Infrared Polarization Survey (GPIPS). These take the form of catalogs of stellar photometry (PHOTCAT) and linear polarimetry (POLCAT) in the near-infrared H-band (1.6 um) for four-hundred 10x10 arcmin fields of view that sample across the full Galactic longitude (L = 18 to 56 deg) and latitude ranges (B = -1 to +1 deg) of GPIPS. Several regions are represented as overlapping fields and have been mosaicked into preliminary Image Tiles (with polarization overlays). Some 60,000 stars as faint as H=12th exhibit significant polarizations and upper limits in these fields. Stars as faint as H=16-17th appear in the photometric catalog. This initial data release is via the GPIPS website (http://gpips0.bu.edu/) and will be linked to the VAO and Vizier. GPIPS is being conducted on the 1.83m Perkins telescope outside Flagstaff, Arizona using the Mimir instrument configured as a near-infrared imaging polarimeter. A total of 3,237 10x10 arcmin fields will span 76 sq. deg of the inner, first quadrant Galactic plane. Data collection is more than 70% complete and should finish in 2013. The GPIPS data products (POLCAT, PHOTCAT, Image Tile Catalog) are being released on a rolling basis and as quickly as the data can be processed and calibrated. The second data release is expected for the fall and should contain nearly 1,000 fields. Supported by NSF grants AST 06-07500 and 09-07790. 321.02 Galactic Plane Infrared Polarization Survey (GPIPS) - Example Science Applications Michael D. Pavel1, D. P. Clemens1, A. F. Pinnick1, J. M. Moreau1, R. Marchwinski1, M. Bartlett1, B. Taylor1 1Boston University. 4:40 PM - 4:50 PM St. George CD With the initial public release of GPIPS data for 400 fields, a wide range of new scientific studies is made possible. This talk will highlight some examples, so as to motivate broad use of this rich data set. Combining the GPIPS/PHOTCAT data products with 2MASS and UKIDSS will enable studies for NIR stellar variability and proper motion, as well as help resolve 2MASS source ambiguities and improve cluster photometry. The GPIPS/POLCAT polarization data catalogs enables mapping magnetic fields across a wide range of extinction, from Av = 1 to 20 mag or more, permitting tracing the field from the edges of molecular clouds to close to the most extincted cloud cores. In addition to assessing the roles played by the magnetic field in helping to order cool clouds and the star formation conditions within them through evaluating the mean field directions, POLCAT data may be analyzed with the Chandrasekhar-Fermi method to develop resolved magnetic field strength maps across fields. Also, comparisons of structure functions of cool cloud velocities and column densities may be compared to magnetic field structure functions to ascertain the relative importance of magnetohydrodynamic vs pure hydrodynamic turbulence. Finally, comparisons of the magnetic properties in the hot ISM, traced through Faraday rotation and synchrotron radiation, may be compared to the field properties in the cool ISM, atomic and molecular clouds, over the same lines of sight to gain an understanding of the coupling of the field across these vastly different ISM components. Supported by NSF grants AST 06-07500 and AST 09-07790. 321.03 The Distance and Stability of the HI Filament that Comprises HVC A0 Gerrit L. Verschuur1, D. L. Nidever2 1University of Memphis, 2University of Virginia. 4:50 PM - 5:00 PM St. George CD The neutral hydrogen structure of high-velocity “cloud” A0 has been mapped using the Green Bank Telescope of the NRAO. The HI gas is in the form of a narrow, twisted filament with a typical line width of order 23 km/s within which regions of enhanced emission with line widths of order 4 to 6 km/s and as high as 15 km/s are located. Gaussian decomposition of the profiles is used to reveal the filament most clearly. If it is in equilibrium with surrounding galactic halo pressure its distance must be about 5,400 pc. However, the observed HI line widths are not a measure of the kinetic temperature of the gas. Instead their magnitude appears to be consistent with the presence of Alfvén waves for a magnetic field of order 2.8 µG. The existence of the bright, narrow line width features is more problematic. Geometry alone may account for their brightness and line widths. On the other hand, if the small-scale structures have angular scales of order 1.’5, lost inside the resolution of our data, these features, too, could be in equilibrium with halo pressure. In either case, the bright features exist relatively independent of the filament structure itself. This work suggests that the distance to HI filaments can be determined provided reliable estimates of surrounding gas pressure are available and if we are reasonably certain that a segment of filament is being viewed side-on. 321.04 The GALFA-HI Survey: Toward the Second Data Release Kevin A. Douglas1, J. E. G. Peek2, J. Grcevich2, D. Saul2, M. Lee3, N. Pingel3, E. J. Korpela4, S. Stanimirovic3, M. E. Putman2, S. J. Gibson5, C. E. Heiles4 1NAIC, 2Columbia University, 3University of Wisconsin-Madison, 4University of California, Berkeley, 5Western Kentucky University. 5:00 PM - 5:10 PM St. George CD The GALFA-HI Survey uses 21-cm spectral line data recorded with the Arecibo L-band Feed Array (ALFA), in an effort to map the neutral hydrogen content of the Galaxy and its nearby environment. The first full public release of data (Peek et al. 2011, ApJS in press) covers approximately 7500 square degrees, from observations spanning the epoch of May 2005 to February 2009. The second data release will include data from GALFA-HI observations to the end of 2010. We will describe the attributes of the survey, and most importantly, how to gain access to the data. 321.05 Molecule Formation in the Heeschan-Riegel-Crutcher Cloud D. Anish Roshi1, N. G. Kantharia2 1National Radio Astronomy Observatory, 2National Center for Radio Astrophysics, TIFR,, India. 5:10 PM - 5:20 PM St. George CD We report, for the first time, that the low frequency carbon recombination lines (CRRLs) from the innermost ∼ 10° of the Galaxy arise in the Heeschan-Riegel-Crutcher (HRC) cloud. The HRC cloud is amongst the most well known of HI self-absorbing (HISA) regions located at a distance of about 125 pc in the Galactic centre direction. We demonstrate that the physical properties of the HISA can be constrained by combining multi-frequency CRRL and HI observations.The derived physical properties of the HISA cloud are used to determine the cooling and heating rates. The dominant cooling process is emission of the CII 158 µm line whereas dominant heating process in the cloud interior is photoelectric emission. Constraints on the FUV flux (G0 ∼ 4 to 7) falling on the HRC cloud are obtained by assuming thermal balance between the dominant heating and cooling processes. The H$_2$ formation rate per unit volume in the cloud interior is ∼ 10$^{-10}$ -- 10$^{-12}$ s$^{-1}$ cm$^{-3}$, which far exceeds the H$_2$ dissociation rate per unit volume. We conclude that the self-absorbing cold HI gas in the HRC cloud may be in the process of converting to the molecular form. The cold HI gas observed as HISA features are ubiquitous in the inner Galaxy and form an important part of the ISM. Our analysis shows that combining CRRL and HI data can give valuable insight into the nature of these cold gas. We also present results from new low-frequency (< 800 MHz) CRRL observations toward HRC cloud using the Green Bank Telescope. 321.06 A Spitzer Survey of an Isolated Globule: DC314.8-5.1 Sachindev S. Shenoy1, D. C. B. Whittet2, Y. J. Pendleton3, C. Boersma1, L. J. Allamandola4, D. Horne2, P. A. Mayeur2 1ORAU - NASA ARC, 2Rensselaer Polytechnic Institute, 3NASA Lunar Science Institute, 4NASA ARC. 5:20 PM - 5:30 PM St. George CD DC314.8-5.1 is an isolated globule in the constellation of Circinus in the southern hemisphere. A 10.53 V-magnitude B9 star is illuminating a reflection nebula in the eastern part of this cloud. We surveyed this cloud using data from Spitzer IRS, IRAC and MIPS instruments. The main goals of our survey are to use mid-IR photometry along with 2MASS data to determine if this globule is a site of active star formation and to use IR spectroscopy to detect PAHs and investigate the energetics in the cloud. Here we describe preliminary results from the investigation of PAH emissions in DC314.8-5.1. Inspection of the IRAC 8 micron image shows widespread structured PAH emission towards this cloud. We have high resolution IRS spectra of HD130079 and low resolution IRS maps of the reflection nebula. In the spectral data we detect all the major PAH emissions in the 5~20 micron region. We find that the emission in the 12~14 micron region is quenched compared to the 11.3 micron feature suggesting most of the PAHs have solo hydrogen bonds. Spatial variation of PAH emissions seems to be identical as we move from the illuminating source, HD130079, towards the interior of the cloud except in the south-southwest region, where we see a slight enhancement. This enhancement is probably due to the skin effect (i.e., an excess due to viewing angle). We will analyze the ratios of various PAH features to i) put this globule in a global context with respect to the energetics of the region, and ii) determine the ionization state of the carrier molecules to investigate the interaction of PAHs with soft UV radiation. Combining results from the spectroscopic program with the stellar census data will provide new insight into the physical and evolutionary state of this isolated globule. 321.07 Measuring Dust with Pan-STARRs Douglas P. Finkbeiner1, E. F. Schlafly1 1Harvard University. 5:30 PM - 5:40 PM St. George CD The colors of main sequence turnoff stars may be used to measure the reddening of the stars by foreground dust. Using Pan-STARRs 3 pi data, we have derived reddenings over a large part of the sky. I will show how these reddening measurements can be used as a calibration check of the PS1 data, and a test of the SFD (1998) dust map. 321.08 Turbulent Molecular Gas and Star Formation in the Shocked Intergalactic Medium of Stephan's Quintet Pierre Guillard1, F. Boulanger2, A. Gusdorf3, M. Cluver1, P. N. Appleton1, G. Pineau des Forets2, P. Ogle1, U. Lisenfeld4, P. Duc5, E. Falgarone6, C. K. Xu1 1Caltech, 2Institut d'Astrophysique Spatiale, France, 3Max Planck Institut für Radioastronomie, Germany, 4Departamento de Física Teórica y del Cosmos, Spain, 5AIM, Unité Mixte de Recherche CEA-CNRS, Université Paris VII, UMR 7158, France, 6ENS, LERMA, UMR 8112, CNRS, Observatoire de Paris, France. 5:40 PM - 5:50 PM St. George CD Spitzer spectroscopy has revealed a significant and diverse population of extragalactic sources where the mid-infrared rotational line emission of warm (> 150 K) molecular hydrogen (H2) is strongly enhanced, while star formation is suppressed. The multi-galaxy collision in Stephan's Quintet (SQ) is one example of these powerful H2 emitters. New CO line observations of the kpc-scale X-ray emitting shock associated with the collision will be presented. The CO gas is extremely turbulent, with FWHM up to 1000km/s, and the warm-to-cold H2 mass ratio is more than one order of magnitude higher than in star-forming galaxies. These observations provide insights into our understanding of how the mechanical energy of the galaxy collision is dissipated, and how this dissipation affects the passage from molecular gas to stars. This astrophysical process is relevant to many other active phases of galaxy evolution (AGN feedback, cooling flows, gas accretion, etc.) where a huge amount of mechanical energy is released in the ISM. Thursday Thursday, May 26, 2011, 8:00 AM - 12:00 PM 405 The Sun and Solar System II Poster Session Essex Ballroom 405.01 Differential Emission Measure Analysis of Coronal Loop Data From AIA, EIS, and XRT Jennifer W. Garst1 1Univ. Of Memphis. 8:00 AM - 12:00 PM Essex Ballroom Last year’s launch of the Solar Dynamics Observatory (SDO) has provided additional data to constrain the temperature of coronal loops, allowing for a more detailed analysis of the nature of the heating. Specifically, the high temperature constraints that have been missing from prior analyses are now available to be considered. Images from a coronal loop on the solar disk on December 10, 2010 from both the Atmospheric Imaging Assembly (AIA) and the X-Ray Telescope (XRT) instruments onboard SDO are analyzed along with data from the same date taken by the Extreme Ultraviolet Imaging Spectrometer (EIS) instrument onboard Hinode. Differential emission measure techniques are used to consider whether the loops are isothermal or multithermal in nature. Conclusions regarding the comparison of this data will be presented. Solar physics research at the University of Memphis is supported by NSF ATM-0402729 as well as a Hinode subcontract from NASA/SAO. 405.02 A New Tool for Classifying Small Solar System Objects Ryan Desfosses1, D. Arel1, M. E. Walker1, J. Ziffer1, T. Harvell1, H. Campins2, Y. R. Fernandez2 1University of Southern Maine, 2University of Central Florida. 8:00 AM - 12:00 PM Essex Ballroom An artificial intelligence program, AutoClass, which was developed by NASA's Artificial Intelligence Branch, uses Bayesian classification theory to automatically choose the most probable classification distribution to describe a dataset. To investigate its usefulness to the Planetary Science community, we tested its ability to reproduce the taxonomic classes as defined by Tholen and Barucci (1989). Of the 406 asteroids from the Eight Color Asteroid Survey (ECAS) we chose for our test, 346 were firmly classified and all but 3 (<1%) were classified by Autoclass as they had been in the previous classification system (Walker et al., 2011). We are now applying it to larger datasets to improve the taxonomy of currently unclassified objects. Having demonstrated AutoClass’s ability to recreate existing classification effectively, we extended this work to investigations of albedo-based classification systems. To determine how predictive albedo can be, we used data from the Infrared Astronomical Satellite (IRAS) database in conjunction with the large Sloan Digital Sky Survey (SDSS), which contains color and position data for over 200,000 classified and unclassified asteroids (Ivesic et al., 2001). To judge our success we compared our results with a similar approach to classifying objects using IRAS albedo and asteroid color by Tedesco et al. (1989). Understanding the distribution of the taxonomic classes is important to understanding the history and evolution of our Solar System. AutoClass’s success in categorizing ECAS, IRAS and SDSS asteroidal data highlights its potential to scan large domains for natural classes in small solar system objects. Based upon our AutoClass results, we intend to make testable predictions about asteroids observed with the Wide-field Infrared Survey Explorer (WISE). 405.03 WISE Observations of Primitive Asteroid Families Julie Ziffer1, H. Campins2, J. Licandro3, M. S. Kelley4, Y. R. Fernandez2, M. Delbo5, K. Hargrove2, V. Alí-Lagoa6 1University of Southern Maine, 2University of Central Florida, 3Departamento de Astrofísica, Universidad de La Laguna,, Spain, 4University of Maryland, Department of Astronomy, 5Laboratoire Cassiopée, Observatoire de la Cote d'Azur, France, 6Instituto de Astrofísica de Canarias, Spain. 8:00 AM - 12:00 PM Essex Ballroom NASA's Wide-field Survey Explorer (WISE) mapped the sky in four bands at 3.4, 4.6, 12, and 22 μm during its mission. Published on 14 April 2011, the WISE Preliminary Release provides data of more than 150,000 asteroids that were processed with initial calibration and reduction algorithms. Our aim is to carry out an analysis of key physical parameters (size, albedo, and thermal properties) of outer main-belt asteroid families. Our study concentrates on the Themis, Veritas, and Hygeia families, but will also include other primitive families (taxonomic types C, P, and D). For each of our target asteroids in the WISE preliminary release, we estimated diameters and albedos by fitting thermal models to the measured fluxes, thus constraining their size distribution and compositions. Our initial results from WISE are part of a more extensive study that includes visible, near-infrared, and mid-infrared spectroscopy. These asteroid families are believed to have experienced less heating than most other asteroids and comparisons with Jupiter Trojans, cometary nuclei, and primitive meteorites can provide strong tests of dynamical and collisional models that relate outer belt asteroids with Transneptunian objects. 405.04 Orbital Stability of Spacecraft Exploring Multiple Asteroid Systems Keaton Burns1, F. Marchis2, J. Bellerose3 1UC Berkeley, 2SETI Institute / UC Berkeley, 3Carnegie Melon University. 8:00 AM - 12:00 PM Essex Ballroom Space missions to study the composition and formation histories of multiple asteroid systems require the identification of safe orbits for the observing spacecraft. To identify regions of orbital stability, we developed an n-body simulation and Monte Carlo scheme to test a large selection of orbits around the components of multiple asteroid systems. Our n-body program integrates the equations of motion of the spacecraft, asteroid system components, and the sun for 20 days, taking into account solar radiation pressure on the spacecraft and modeling asteroids as systems of rigid points when their shape model is known. We utilized a Monte Carlo scheme to test the stability of polar and retrograde orbits from uniformly distributed starting positions with normally distributed tangential velocities around each component. We present preliminary results of simulations testing hundreds of thousands of polar and retrograde orbits around the components of the 2001 SN263 near-earth triple asteroid system, and the (90) Antiope doublet and (45) Eugenia triple systems in the main-belt. These systems are potential targets for several space mission concepts, including: the Amor mission to visit and land on the components of 2001 SN263, Jones et al. (LPSC 42, #2695, 2011), the Diversity mission to explore several asteroid systems including (45) Eugenia and (90) Antiope, Marchis et al. (LPSC 42, #2062, 2011), and the ASTER mission to visit a NEA multiple asteroid, Sukhanov et al. (Cosmic Research 48-5, p. 443-450, 2010). Analysis of stable regions in position and velocity may assist in planning scientific orbits and instrumental specifications for such missions. 405.05 A Lightcurve and Color Analysis of Asteroid 4709 Ennomos Thomas Harvell1, J. Ziffer1, Y. R. Fernandez2, M. Reuillard1, M. E. Walker1 1University of Southern Maine, 2University of Central Florida. 8:00 AM - 12:00 PM Essex Ballroom We will present results from our study of the Jovian Trojan asteroid 4709 Ennomos, an asteroid with an unusually high estimated albedo. Large Trojan asteroids (radius > 25 km) have a mean V-band geometric albedo of 0.041 with very little variation (standard deviation = 0.007 ; Fernandez et. al. 2003). Smaller Trojan asteroids, with radius < 25 km, have both higher albedo (mean = 0.12) and wider variation (standard deviation = 0.065; Fernandez et. al. 2010). Asteroid 4709 Ennomos has a radius of about 38 km and a geometric albedo of about 0.15: several standard deviations above the mean albedo of other large Trojans, but very similar to the albedos of small Trojans. One plausible explanation of Ennomos’ apparently high albedo is that its rotation period may be sufficiently fast so as to invalidate the use of a low-thermal memory thermal model to calculate its size and albedo--the model used for Ennomos. To test this hypothesis, we obtained time series CCD photometry of Ennomos’ light curve using the University of Hawaii 88-inch telescope on UT February 8 through 10, 2003. Analysis of Ennomos’ light curve and rotation period will determine if an isothermal latitude model is more appropriate. Since asteroids of Ennomos’ size, both Trojans and Main-Belt, tend to be relatively slow rotators, a high rotation speed would be unusual. We therefore also consider some of the other hypotheses to explain Ennomos’ high albedo. For example, comparing Ennomos’ colors to those of other asteroid groups can give clues to the reason for an elevated albedo. To this end, we also obtained BVRI colors of Ennomos during our 2003 observing run. We will present a comparison between Ennomos’ colors, other published large Trojan and small Trojan colors (e.g. Jewitt & Luu 1990), and small asteroid colors (e.g. Karlsson et al. 2009). 405.06 The Potential of AutoClass as an Asteroidal Data Mining Tool Matthew Walker1, J. Ziffer1, T. Harvell1, Y. R. Fernandez2, H. Campins2 1University of Southern Maine, 2University of Central Florida. 8:00 AM - 12:00 PM Essex Ballroom AutoClass-C, an artificial intelligence program designed to classify large data sets, was developed by NASA to classify stars based upon their infrared colors. Wanting to investigate its ability to classify asteroidal data, we conducted a preliminary test to determine if it could accurately reproduce the Tholen taxonomy using the data from the Eight Color Asteroid Survey (ECAS). For our initial test, we limited ourselves to those asteroids belonging to S, C, or X classes, and to asteroids with a color difference error of less than +/- 0.05 magnitudes. Of those 406 asteroids, AutoClass was able to confidently classify 85%: identifying the remaining asteroids as belonging to more than one class. Of the 346 asteroids that AutoClass classified, all but 3 (<1%) were classified as they had been in the Tholen classification scheme. Inspired by our initial success, we reran AutoClass, this time including IRAS albedos and limiting the asteroids to those that had also been observed and classified in the Bus taxonomy. Of those 258 objects, AutoClass was able to classify 248 with greater than 75% certainty, and ranked albedo, not color, as the most influential factor. Interestingly, AutoClass consistently put P type objects in with the C class (there were 19 P types and 7 X types mixed in with the other 154 C types), and omitted P types from the group associated with the other X types (which had only one rogue B type in with its other 49 X-types). Autoclass classified the remaining classes with a high accuracy: placing one A and one CU type in with an otherwise perfect S group; placing three P type and one T type in an otherwise perfect D group; and placing the four remaining asteroids (V, A, R, and Q) into a class together. 406 Extrasolar Planets Poster Session Essex Ballroom 406.01 ExoplanetSat Constellation Mary Knapp1, R. Jensen-Clem1, S. Seager1, D. Miller1, M. W. Smith1 1MIT. 8:00 AM - 12:00 PM Essex Ballroom ExoplanetSat combines the low cost CubeSat platform with an innovative two-stage attitude control system to detect exoplanets. ExoplanetSat will be capable of detecting transiting Earth-sized planets in the habitable zone of the brightest sun-like stars with a detection threshold of 7σ. After the successful flight of the first ExoplanetSat prototype, the concept for the complete ExoplanetSat constellation is to search for Earth-sized planets around sun-like stars brighter than visual magnitude 8. In order to develop a tractable target star list of a few hundred stars out of the 1000+ bright sun-like stars available, the goal is to choose target stars with the highest probability for transiting planets based on stellar inclination constraints as determined from asteroseismology. The ExoplanetSat Constellation will consist of dozens of 3U, 6U, and larger CubebSat units. 406.02 ExoplanetSat: The Search for Earth-Sized Planets Rebecca Jensen-Clem1, S. Seager1, M. W. Smith1, C. Pong1, M. Knapp1, D. Miller1 1MIT. 8:00 AM - 12:00 PM Essex Ballroom ExoplanetSat combines the low cost CubeSat platform with an innovative two-stage attitude control system to detect exoplanets. ExoplanetSat will be capable of detecting transiting Earth-sized planets in the habitable zone of the brightest sun-like stars with a detection threshold of 7 sigma. The choice of targeting the brightest sun-like stars is motivated by the desire to conduct spectral follow-up observations to determine the habitability of exoplanet candidates. We present the design of the first three-unit ExoplanetSat, which will launch in the next two years under NASA's CubeSat Launch Initiative. 406.03 Science Capabilities Of A Next-generation UV/O/NIR Telescope With A Starshade Tiffany M. Glassman1, A. S. Lo1 1Northrop Grumman Aerospace Systems. 8:00 AM - 12:00 PM Essex Ballroom The search for exoplanets is an important goal for the astronomy community in the next decade. Direct imaging and spectroscopy of terrestrial planets in the habitable zones of nearby stars has been identified as a key goal by the ASTRO2010 Decadal Survey. However, any flagship-scale exoplanet mission will also have to provide advanced capabilities that are useful to the entire astronomy community. A large aperture, general purpose, UV-Optical-NIR telescope in the 2020 decade will provide an important continuation and expansion of the capabilities currently provided by the Hubble Space Telescope. In this poster, we discuss the compatibility of a starshade with such a telescope. The starshade architecture is very flexible and can accommodate telescopes with a wide range of designs and requirements, partly because starshades levy almost zero requirements on a telescope. This allows the goals of the Exoplanet community to be achieved while maintaining the capabilities of a general purpose astronomical telescope. 406.04 Fiber Scrambling for High Precision Spectrographs Zachary Kaplan1, J. F. P. Spronck1, D. Fischer1 1Yale University. 8:00 AM - 12:00 PM Essex Ballroom The detection of Earth-like exoplanets with the radial velocity method requires extreme Doppler precision and long-term stability in order to measure tiny reflex velocities in the host star. Recent planet searches have led to the detection of so called “super-Earths” (up to a few Earth masses) that induce radial velocity changes of about 1 m/s. However, the detection of true Earth analogs requires a precision of 10 cm/s. One of the largest factors limiting Doppler precision is variation in the Point Spread Function (PSF) from observation to observation due to changes in the illumination of the slit and spectrograph optics. Thus, this stability has become a focus of current instrumentation work. Fiber optics have been used since the 1980’s to couple telescopes to high-precision spectrographs, initially for simpler mechanical design and control. However, fiber optics are also naturally efficient scramblers. Scrambling refers to a fiber’s ability to produce an output beam independent of input. Our research is focused on characterizing the scrambling properties of several types of fibers, including circular, square and octagonal fibers. By measuring the intensity distribution after the fiber as a function of input beam position, we can simulate guiding errors that occur at an observatory. Through this, we can determine which fibers produce the most uniform outputs for the severest guiding errors, improving the PSF and allowing sub-m/s precision. However, extensive testing of fibers of supposedly identical core diameter, length and shape from the same manufacturer has revealed the “personality” of individual fibers. Personality describes differing intensity patterns for supposedly duplicate fibers illuminated identically. Here, we present our results on scrambling characterization as a function of fiber type, while studying individual fiber personality. 406.05 On the Frequency of Additional Planets in Short Period Hot Jupiter Systems from Transit Timing Variations Jason Dittmann1, L. Close2, L. Scuderi2 1Harvard Center For Astrophysics, 2University of Arizona. 8:00 AM - 12:00 PM Essex Ballroom The large number of hot Jupiter planets allows one to probe these systems for additional unseen planets via transit timing variations (TTVs). Even relatively small terrestrial planets, when placed in an energetically favorable mean motion resonance (MMR), can cause detectable TTVs with an amplitude of several minutes (Holman and Murray 2005, Agol et al. 2005). In an effort to discover and characterize such companions, we have embarked on a systematic study of known transiting hot Jupiters, utilizing the 1.55 meter Kuiper telescope on Mt. Bigelow to measure multiple individual transits in an observing season to within 30 second precision, and constrain the nature of any planetary companions. Here, we present current and preliminary results on this study, and show that the systems HAT-P-5, HAT- P-6, HAT-P-8, HAT-P-9, WASP-11/HAT-P-10, HAT-P-11, TrES-2, and WASP-10 do not contain small mass companions in MMRs, or moderate mass companions in close enough proximity to induce TTVs on the order of ~ 1.5 minutes. 406.06 New Exo-Planet Candidates Discovered by the Citizen Scientists of PlanetHunters.org John Michael Brewer1, D. A. Fischer1, M. E. Schwamb1, M. J. Giguere1, T. Sartori1, C. J. Lintott2, S. Lynn3, A. Smith3, K. Schawinski1, J. Spronck1, R. Simpson3 1Yale University, 2Adler Planetarium, 3University of Oxford, United Kingdom. 8:00 AM - 12:00 PM Essex Ballroom The unprecedented precision and cadence of Kepler photometry has already resulted in a wealth of new candidate planetary systems. However, it has also given us a window into a previously unseen stellar variability regime that tests the ability of software algorithms to identify transits in the astrophysical 'noise'. Using the publicly released Kepler data, we built the PlanetHunters.org Zooniverse web site to take advantage of the natural pattern recognition capabilities of large numbers of citizen scientists. Individuals classify lightcurve variability and mark transits using simple interactive plots on the web site. After one month in operation using only the first 32 days of data, more than 1.1 million light curves were classified and users identified 90 strong potential candidates. Here we present information about 5 unique planet candidates which have undergone extensive testing for false positives and have not been subsequently published by the Kepler team. We have also taken Keck HIRES spectra of the stellar hosts and so provide precise planetary radii and periods as well as improved stellar properties. 406.07 The Occurrence Rate of Earth Analog Planets Orbiting Sunlike Stars Joseph Catanzarite1, M. Shao1 1JPL. 8:00 AM - 12:00 PM Essex Ballroom Title: The Occurrence Rate of Earth Analog Planets Orbiting Sunlike Stars Authors: Joseph Catanzarite and Michael Shao, Jet Propulsion Laboratory, California Institute of Technology Summary Kepler is a space telescope that searches Sun-like stars for planets. Its major goal is to determine eta_Earth, the fraction of Sunlike stars that have planets like Earth. When a planet ‘transits’ or moves in front of a star, Kepler can measure the concomitant dimming of the starlight. From analysis of the first four months of those measurements for over 150,000 stars, Kepler’s science team has determined sizes, surface temperatures, orbit sizes and periods for over a thousand new planet candidates. In this paper, we characterize the period probability distribution function of super-Earths and Neptunes with periods up to 132 days, and find three distinct period regimes. For planets with periods below 3 days the density increases sharply with increasing period; for periods between 3 and 30 days the density rises more gradually with increasing period, and for periods longer than 30 days, the density drops gradually with increasing period. We estimate that 1% to 3% of stars like the Sun are expected to have Earth analog planets, based on the Kepler data release of Feb 2011. The estimate will improve when it is based on the full 3.5 to 6 year Kepler data set. Accurate knowledge of eta_Earth is essential for the planning of future missions that will image and take spectra of Earthlike planets. Our result that Earths are relatively scarce means that a substantial effort will be needed to identify suitable target stars prior to these future missions. 406.08 Inflated Hot Jupiters may not Require Inflated Physics Eduardo L. Martin1, H. Spruit2 1INTA-CSIC Centro de Astrobiologia, Spain, 2Max-Planck-Institut fur Astrophysik, Germany. 8:00 AM - 12:00 PM Essex Ballroom Due to the Darwin instability, hot Jupiters are expected to spiral in and merge with their host stars. The time scale for this spiral-in can be readily calculated for transiting hot Jupiters, but it is subject to uncertainty in the tidal dissipation parameter Q. Using data available for a sample of over one hundred transiting planets, we calculate the time it takes for hot Jupiters to spiral in from their current distance to their host stars. It is found that the spiral in times are strongly correlated with the excess of the planet's radius relative to its equilibrium radius in the sense that larger radius anomalies correspond to shorter spiral in times. An energy source has to be invoked to keep planets inflated longer than their natural cooling time. Irradiation by the host star has been considered but a plausible mechanism to transport the irradiating flux to the planet interior where it is needed for significant inflation has not yet been identified. A 1 Jupiter mass planet needs an thermal energy excess of the order of its gravitational binding energy in order to inflate it by as much as 50 percent. This rules out a source like dissipation of tides in the planet due to nonsynchronous rotation, since the maximum rotational energy of a planet is only a fraction of its binding energy. We propose that the cause of inflation is that the hot Jupiters are young, typically a few hundred Myr. The reason for this youth is hot Jupiter formation in the merger of a binary. The likely binary populations include W~UMa stars (contact binaries) and low mass detached binaries. This scenario also explains other puzzling properties of hot Jupiters, such as their high abundance in orbits close to the host stars and enhanced lithium depletion. 407 Stars, Star Formation and Associated Topics Poster Session Essex Ballroom 407.01 The Effect Of Limited Spatial Resolution Of Stellar Surface Magnetic Field Maps On Mhd Wind And Coronal X-ray Emission Models Cecilia Garraffo1, O. Cohen1, J. J. Drake1, C. Downs2 1Harvard-Smithsonian CfA, 2Institute for Astronomy, University of Hawaii at Manoa. 8:00 AM - 12:00 PM Essex Ballroom We study the influence of the spatial resolution of solar and stellar surface magnetic field maps on global MHD solar and stellar wind models, and on a model of coronal heating and X-ray emission. For the Sun, we compare the solutions driven by a low-resolution WSO map, the same map with spatial resolution artificially increased by a refinement algorithm, and a high-resolution MDI map. We perform a similar test for the planet-bearing K1-2V star HD 189733, comparing MHD wind solutions and X-ray morphology and flux for a Zeeman-Doppler imaging magnetic map, and the same map with artificially enhanced spatial resolution. In both solar and stellar cases, the large-scale wind structure is dominated by the lower-order magnetic components and is little affected by fine-scale surface magnetic structure. Provided the low-order field is properly resolved, MHD wind models applied to solar-like stars should be reliable. Instead, the X-ray morphology is dominated by the closed loop structure between mixed polarities on smaller scales and shows significant changes between high and low resolution maps. We conclude that three-dimensional modell