This week on HST


HST Programs: March 7, 2011 - March 13, 2011

Program Number Principal Investigator Program Title
11557 Gabriela Canalizo, University of California - Riverside The Nature of low-ionization BAL QSOs
11582 Andrew Blain, California Institute of Technology The spatial distribution of radiation in the complex ISM of distant ultraluminous galaxies
12018 Andrea H. Prestwich, Smithsonian Institution Astrophysical Observatory Ultra-Luminous x-Ray Sources in the Most Metal-Poor Galaxies
12039 James C. Green, University of Colorado at Boulder COS-GTO: X-Ray Binaries
12066 Marc Postman, Space Telescope Science Institute Through a Lens, Darkly - New Constraints on the Fundamental Components of the Cosmos
12068 Marc Postman, Space Telescope Science Institute Through a Lens, Darkly - New Constraints on the Fundamental Components of the Cosmos
12161 David R. Ardila, Jet Propulsion Laboratory Accretion in Close Pre-Main-Sequence Binaries
12166 Harald Ebeling, University of Hawaii A Snapshot Survey of The Most Massive Clusters of Galaxies
12209 Adam S. Bolton, University of Utah A Strong Lensing Measurement of the Evolution of Mass Structure in Giant Elliptical Galaxies
12212 D. Michael Crenshaw, Georgia State University Research Foundation What are the Locations and Kinematics of Mass Outflows in AGN?
12231 Paula Szkody, University of Washington An Unprecedented Opportunity to Follow 4 Accreting WDs into the Instabilty Strip
12233 Frederic Courbin, Ecole Polytechnique Federale de Lausanne Strong Gravitational Lensing by Quasars
12264 Simon L. Morris, University of Durham The Relationship between Gas and Galaxies for 0
12269 Claudia Scarlata, California Institute of Technology The escape of Lya photons in star-forming galaxies
12272 Christy A. Tremonti, University of Wisconsin - Madison Testing Feedback: Morphologies of Extreme Post-starburst Galaxies
12276 Bart P. Wakker, University of Wisconsin - Madison Mapping a nearby galaxy filament
12278 Thomas R. Ayres, University of Colorado at Boulder Advanced Spectral Library Project: Cool Stars
12283 Matthew A. Malkan, University of California - Los Angeles WFC3 Infrared Spectroscopic Parallel Survey {WISP}: A Survey of Star Formation Across Cosmic Time
12286 Hao-Jing Yan, The Ohio State University Hubble Infrared Pure Parallel Imaging Extragalactic Survey {HIPPIES}
12299 Michael Eracleous, The Pennsylvania State University Spectroscopic Signatures of Binary and Recoiling Black Holes
12308 Eric M. Monier, State University of New York College at Brockport Cosmic Metallicity from ZnII-Selected QSO Absorption Line Systems Near Redshift z=1.2
12310 Goeran Oestlin, Stockholm University LARS - The Lyman Alpha Reference Sample
12363 Yue Shen, Smithsonian Institution Astrophysical Observatory X-ray and HST Imaging of Kpc-Scale Binary AGNs
12376 Vinay Kashyap, Smithsonian Institution Astrophysical Observatory The Spinning Corona of FK Comae
12441 Edmund Nelan, Space Telescope Science Institute FGS Science During NSSC-1 Flight Software Upgrade

Selected highlights

GO 12209: A Strong Lensing Measurement of the Evolution of Mass Structure in Giant Elliptical Galaxies

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 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. The present survey aims to target a particular type of galaxy - luminous giant ellipticals. Spectroscopic data from the recently initiatiated Baryon Oscillation Spectroscopic Survey (BOSS). sampling luminous ellipticals at redshifts between z~0.4 and 0.7, has been used to identify candidate strong lens systems. The present program is using HST I-band (F814W) ACS-WFC imaging to verify the nature of those candidates, and, for confirmed sources, provide the angular resolution necessary to model the mass distribution of the lensing system.

GO 12264: The Relationship between Gas and Galaxies for 0

A computer simulation of galactic gas accretion and outflow Galaxy formation, and the overall history of star formation within a galaxy, demands the presence of abundant gaseous material. The detailed evolution of individual systems depends on how gas is accreted, recycled, circulated through the halo 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 observe four QSOs with redshifts in the range 1 < z < 1.2. All four lie within regions of the sky that have been well surveyed for galaxies, with extensive data already available describing the redshift distribution of large-scale structures along the line of sight. The QSOs provide the background sources, and the goal is to use COS observations with the G130M and G160M gratings to probe hot gas along the line of sight, and match that distribution against the galaxian data.

GO 12283: WISP - A Survey of Star Formation Across Cosmic Time

A region of massive star formation Star formation is the key astrophysical process in determining the overall evolution of galactic systems, the generation of heavy elements, and the overall enrichment of interstellar and intergalactic material. Tracing the overall evolution through a wide redshift range is crucial to understanding how gas and stars evolved to form the galaxies that we see around us now. The present program builds on the ability of HST to carry out parallel observations, using more than one instrument. While the Cosmic Origins Spectrograph is focused on obtaining ultraviolet spectra of unparalleled signal-to-noise, this program uses the near-infrared grisms mounted on the Wide-Field Camera 3 infrared channel to obtain low resolution spectra between 1 and 1.6 microns of randomly-selected nearby fields. The goal is to search for emission lines characteristic of star-forming regions. In particular, these observations are capable of detecting Lyman-alpha emission generated by star formation at redshfits z > 5.6. A total of up to 40 "deep" (4-5 orbit) and 20 "shallow" (2-3 orbit) fields will be targeted in the course of this observing campaign.

Past weeks:
page by Neill Reid, updated 2/5/2011