| Program Number | Principal Investigator | Program Title |
|---|---|---|
| 11516 | James C. Green, University of Colorado at Boulder | COS-GTO: Cold ISM |
| 12445 | Sandra M. Faber, University of California - Santa Cruz | Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey -- GOODS-North Field, Late Visits of SNe Search |
| 12466 | Jane C. Charlton, The Pennsylvania State University | The State of High Ionization Gas in 11 Intermediate Redshift Galaxies and Their Surroundings |
| 12488 | Mattia Negrello, Open University | SNAPshot observations of gravitational lens systems discovered via wide-field Herschel imaging |
| 12523 | Charlie Conroy, University of California - Santa Cruz | Dissecting the integrated light of a massive elliptical galaxy with pixel-to-pixel fluctuations: is the IMF bottom-heavy? |
| 12539 | Nils Bergvall, Uppsala Astronomical Observatory | A novel approach to find Lyman continuum leaking galaxies at z~0.3 with COS |
| 12547 | Michael Cooper, University of California - Irvine | Measuring the Star-Formation Efficiency of Galaxies at z > 1 with Sizes and SFRs from HST Grism Spectroscopy |
| 12568 | Matthew A. Malkan, University of California - Los Angeles | WFC3 Infrared Spectroscopic Parallel Survey WISP: A Survey of Star Formation Across Cosmic Time |
| 12590 | Casey Papovich, Texas A & M University | Galaxy Assembly at High Densities: HST Dissection of a Cluster at z=1.62 |
| 12603 | Timothy M. Heckman, The Johns Hopkins University | Understanding the Gas Cycle in Galaxies: Probing the Circumgalactic Medium |
| 12608 | Moire Prescott, University of Copenhagen, Niels Bohr Institute | Small-scale Morphology and Continuum Colors of Giant Lya Nebulae |
| 12679 | Adam Riess, The Johns Hopkins University | Luminosity-Distance Standards from Gaia and HST |
| 12756 | Ming Sun, Eureka Scientific Inc. | X-raying the spectacular star-forming trail behind IC 3418 |
| 12861 | Xiaohui Fan, University of Arizona | Morphologies of the Most UV luminous Lyman Break Galaxies at z~3 |
| 12870 | Boris T. Gaensicke, The University of Warwick | The mass and temperature distribution of accreting white dwarfs |
| 12880 | Adam Riess, The Johns Hopkins University | The Hubble Constant: Completing HST's Legacy with WFC3 |
| 12884 | Harald Ebeling, University of Hawaii | A Snapshot Survey of The Most Massive Clusters of Galaxies |
| 12903 | Luis C. Ho, Carnegie Institution of Washington | The Evolutionary Link Between Type 2 and Type 1 Quasars |
| 12971 | Harvey B. Richer, University of British Columbia | Completing the Empirical White Dwarf Cooling Sequence: Hot White Dwarfs in 47 Tucanae |
| 12982 | Nicolas Lehner, University of Notre Dame | Are the Milky Way's High Velocity Clouds Fuel for Star Formation or for the Galactic Corona? |
| 13003 | Michael D. Gladders, University of Chicago | Resolving the Star Formation in Distant Galaxies |
| 13023 | Marco Chiaberge, Space Telescope Science Institute - ESA | Universe in transition: powerful activity in the Bright Ages |
| 13025 | Andrew J. Levan, The University of Warwick | Unveiling the progenitors of the most luminous supernovae |
| 13029 | Alex V. Filippenko, University of California - Berkeley | A Snapshot Survey of the Sites of Recent, Nearby Supernovae |
| 13032 | Carol A. Grady, Eureka Scientific Inc. | Crossing the Snow Line: Mapping Ice Photodesorption products in the Disks of Herbig Ae-Fe stars |
| 13046 | Robert P. Kirshner, Harvard University | RAISIN: Tracers of cosmic expansion with SN IA in the IR |
| 13057 | Kailash C. Sahu, Space Telescope Science Institute | Detecting and Measuring the Masses of Isolated Black Holes and Neutron Stars through Astrometric Microlensing |
GO 12488: SNAPshot observations of gravitational lens systems discovered via wide-field Herschel imaging
ACS images of galaxy-galaxy Einstein ring lenses from the Sloan survey |
Gravitational lensing is a consequence the theory of general relativity. Its importance as an astrophysical tool first became apparent with the realisation (in 1979) that the quasar pair Q0957+561 actually comprised two lensed images of the same background quasar. In the succeeding years, lensing has been used primarily to probe the mass distribution of galaxy clusters, using theoretical models to analyse the arcs and arclets that are produced by strong lensing of background galaxies, and the large-scale mass distribution, through analysis of weak lensing effects on galaxy morphologies. Gravitational lensing can also be used to investigate the mass distribution of individual galaxies. Until recently, the most common background sources that were being detected and investigates were quasars. Galaxy-galaxy lenses, however, offer a distinct advantage, since the background source is extended, and therefore imposes a stronger constraints on the mass distribution of the lensing galaxy than a point-source QSO. HST has carried out a number of programs following up candidate lenses identified from the Sloan Digital Sky Survey (eg GO 10886 , GO 11289 , GO 12210 ). The present program is using WFCE on HST to obtain follow-up near-infrared (F110W) images of up to 200 candidate lenses selected from the Herschel Astrophysical Terahertz Large Area (H-ATLAS) and the Herschel Multi-tiered Extra-galactic (HerMES) surveys. The HST data will verify the nature of those candidates, and provide the angular resolution necessary to model the mass distribution. |
GO 12590: Galaxy Assembly at High Densities: HST Dissection of a Cluster at z=1.62
Spitzer imaging of the hgihredshift cluster, IRC0218-0510 |
Most galaxies in the present univese are found in clusters, which are generally believed to have assembled
at redshifts between z~1 and ~3, a period that also coincided with the peak in the star formation rate.
Understanding how these clusters assembled is clearly important to understanding the overall question of
galaxy formation, particularly probing how the dense environment might affect the properties of
individual galaxies, and identifying individual high redshift clusters that enable |
GO 12603: Understanding the Gas Cycle in Galaxies: Probing the Circumgalactic Medium
A computer simulation of galactic gas accretion and outflow |
Galaxy formation, and the overall history of star formation within a galaxy, clearly demands the presence of gas. The detailed evolution therefore is tied very closely to how gas is accreted, recycled, circulated through the halo and disk, and, perhaps, ejected back into the intergalactic medium. Tracing that evolutionary history is difficult, since gas passes through many different phases, some of which are easier to detect than others. During accretion and, probably, subsequent recycling, the gas is expected to be reside predominantly at high temperatures. The most effective means of detecting such gas is through ultraviolet spectroscopy, where gas within nearby systems can be detected as absorption lines superimposed on the spectra of more distant objects, usually quasars. The present program is using the Cosmic Origins Spectrograph to probe gas in the circumgalactic medium for a large sample of relatively local disk galaxies. The targets are drawn from the GALEX Arecibo SDSS Survey (GASS), with the aim of combining the various observations to map atomic, molecular and ionised gas in these systems. The galaxies lie at redshifts between 0.02 and 0.05, and COS will be used to observe QSOs whose sightlines pass within 250 kpc of the galaxy core. Those sightlines run through the halos of the galaxies, and the QSOs therefore provide a pencilbeam backlight that probes hot circumgalactic gas. |
GO 13057: Detecting and Measuring the Masses of Isolated Black Holes and Neutron Stars through Astrometric Microlensing
A rather spectacular version of black hole lensing. |
Gravitational lensing is a consequence of general relativity. Its effects were originally quantified by Einstein himself in the mid-1920s. In the 1930s, Fritz Zwicky suggested that galaxies could serve as lenses, but lower mass objects can also also lens background sources. Bohdan Paczynski pointed out in the mid-1980s that this offered a means of detecting dark, compact objects that might contribute to the dark-matter halo. Paczcynski's suggestion prompted the inception of several large-scale lensing surveys, notably MACHO, OGLE, EROS and DUO. Those wide-field imaging surveys have target high density starfields towards the Magellanic Clouds and the Galactic Bulge, and have succeeded in identifying numerous lensing events. The duration of each event depends on several factors, including the tangential motion of the lens and its mass. Long-term events are generally associated with a massive lens. Duration alone is not sufficient to identify a lens as a black hole - a source with very low tangential motion relative to the Sun can produce the same effect. However, microlensing not only leads to flux amplification, but also to small astrometric motions, caused by the appearance and disappearance of features in the lensed light. Those motions serve as a mass discriminant - higher mass lenses produce larger amplitude motions. The expected astrometric signal from a black hole lens is > 1.4 millarcseconds, just measureable with HST. This program aims to capitalise on this fact by searching for lensing by black holes in the Galactic field. The observations target long-duration lensing events in the Galactic Bulge. |