This week on HST


HST Programs: December 20, 2010 - December 26, 2010

Program Number Principal Investigator Program Title
11565 Sebastien Lepine, American Museum of Natural History A search for astrometric companions to very low-mass, Population II stars
11582 Andrew Blain, California Institute of Technology The spatial distribution of radiation in the complex ISM of distant ultraluminous galaxies
11591 Jean-Paul Kneib, Laboratoire d'Astrophysique de Marseille Are Low-Luminosity Galaxies Responsible for Cosmic Reionization?
11611 D. Michael Crenshaw, Georgia State University Research Foundation Are Narrow-Line Seyfert 1 Galaxies Viewed Pole-on?
11644 Michael E Brown, California Institute of Technology A dynamical-compositional survey of the Kuiper belt: a new window into the formation of the outer solar system
11696 Matthew A. Malkan, University of California - Los Angeles Infrared Survey of Star Formation Across Cosmic Time
12021 Philip Kaaret, University of Iowa An Irradiated Disk in an Ultraluminous X-Ray Source
12058 Julianne Dalcanton, University of Washington A Panchromatic Hubble Andromeda Treasury - I
12061 Sandra M. Faber, University of California - Santa Cruz Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey -- GOODS-South Field, Early Visits of SNe Search
12169 Boris T. Gaensicke, The University of Warwick The frequency and chemical composition of planetary debris discs around young white dwarfs
12174 Zhiyuan Li, Smithsonian Institution Astrophysical Observatory An HST/WFC3 mapping of optical emission lines from the nuclear spiral in M31
12184 Xiaohui Fan, University of Arizona A SNAP Survey for Gravitational Lenses Among z~6 Quasars
12228 Glenn Schneider, University of Arizona Probing for Exoplanets Hiding in Dusty Debris Disks: Inner {<10 AU} Disk Imaging, Characterization, and Exploration
12264 Simon L. Morris, University of Durham The Relationship between Gas and Galaxies for 0
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
12284 James Muzerolle, Space Telescope Science Institute Light Echoes from a Periodic Protostellar Outburst
12289 J. Christopher Howk, University of Notre Dame A COS Snapshot Survey for z < 1.25 Lyman Limit Systems
12307 Andrew J. Levan, The University of Warwick A public SNAPSHOT survey of gamma-ray burst host galaxies
12324 C. S. Kochanek, The Ohio State University The Temperature Profiles of Quasar Accretion Disks
12326 Keith S. Noll, Space Telescope Science Institute Hubble Heritage 2.0

Selected highlights

GO 11696: Infrared 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.

GO 12058: A Panchromatic Hubble Andromeda Treasury

M31: the Andromeda spiral galaxy M31, the Andromeda galaxy, is the nearest large spiral system to the Milky Way (d ~ 700 kpc), and, with the Milky Way, dominates the Local Group. The two galaxies are relatively similar, with M31 likely the larger system; thus, Andromeda provides the best opportunity for a comparative assessment of the structural properties of the Milky Way. Moreover, while M31 is (obviously) more distant, our external vantage point can provide crucial global information that complements the detailed data that we can acquire on individual members of the stellar populations of the Milky Way. With the advent on the ACS and, within the last 2 years, WFC3 on HST, it has become possible to resolve main sequence late-F and G dwarfs, permitting observations that extend to sub-solar masses in M31's halo and disk. Initially, most attention focused on the extended halo of M31 (eg the Cycle 15 program GO 10816 ), with deep imaging within a limited number of fields revealing the complex metallicity structure within that population. With the initiation of the present Multi-Cycle Treasury program, attention switches to the M31 disk. "PHAT" will conduct a multi-waveband survey of approximately one third of disk and bulge, focusing on the north-east quadrant. Observations will extend over the next three cycles, and will provide a thorough census of upper main-sequence stars and star forming regions, matching the stellar distribution against the dust and gas distribution.
GO 12184: A SNAP Survey for Gravitational Lenses Among z~6 Quasars

Temporal variation in the intensities of the lensed components of the Einstein Cross Gravitational lensing is a consequence 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 also increases the apparent brightness of the background sources. This effect can be used to our advantage, in enabling detailed observations of high-redshift sources that be too faint to observe under normal circumstances, but it can also lead to statistical biases in parameters such as luminosity functions. These effects are likely to be of most importance for higher redshift sources, where the longer pathlength leads to a higher probability of the light encountering a foreground lens. The present program aims to address this issue for by using WFC3 to obtain high resolution images F105W ("Y"-band) of a subset of 54 QSOs with redshifts in the range 5.7 < z < 6.4.

GO 12228: Probing for Exoplanets Hiding in Dusty Debris Disks: Inner <10 AU Disk Imaging, Characterization, and Exploration

HST-ACS image of the disk surrounding the nearby M dwarf, AU Mic Planet formation occurs in circumstellar disks around young stars. Most of the gaseous content of those disks dissipates in less than 10 million years, leaving dusty debris disks that are detectable through reflect light at near-infrared and, to a lesser extent, optical wavelengths. The disk structure is affected by massive bodies (i.e. planets and asteroids), which, through dynamical interactions and resonances, can produce rings and asymmetries. Over the past decade, HST and Spitzer have provided complementary information on this subject, with Spitzer measuring thermal radiation from circumstellar dust and HST providing high-resolution mapping of debris disks in reflected light. Most recently, HST ACS coronagraphic imaging have revealed the presence of a planetary object within the disk of the nearby A star, . Planetary companions to the young (60 Myr-old) F star, HR 8799, have also been imaged by both ground-based telescopes and HST. The ACS coronagraph was associated with the High Resolution Camera, which is no longer functioning; nor is NICMOS. However, coronagraphy is still possible using the occulting bar on the Space Telescope Imaging Spectrograph (STIS). The present program aims to expand the catalogue of imaged exoplanets to other nearby young stars that are known to harbour debris disks. The present set of observations targets the young, nearby M dwarf, AU Mic (or Gliese 803).

Past weeks:
page by Neill Reid, updated 12/19/2010