This week on HST


HST Programs: June 6, 2011 - June 12, 2011

Program Number Principal Investigator Program Title
11631 I. Neill Reid, Space Telescope Science Institute Binary brown dwarfs and the L/T transition
12027 James C. Green, University of Colorado at Boulder COS-GTO: STAR FORMATION/LYMAN-ALPHA Part 2
12060 Sandra M. Faber, University of California - Santa Cruz Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey -- GOODS-South Field, Non-SNe-Searched Visits
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
12162 Aaron J. Barth, University of California - Irvine A Definitive Gas-Dynamical Measurement of the Black Hole Mass in M87
12166 Harald Ebeling, University of Hawaii A Snapshot Survey of The Most Massive Clusters of Galaxies
12178 Scott F. Anderson, University of Washington Spanning the Reionization History of IGM Helium: a Highly Efficient Spectral Survey of the Far-UV-Brightest Quasars
12181 Drake Deming, NASA Goddard Space Flight Center The Atmospheric Structure of Giant Hot Exoplanets
12184 Xiaohui Fan, University of Arizona A SNAP Survey for Gravitational Lenses Among z~6 Quasars
12185 Jenny E. Greene, University of Texas at Austin The Hosts of Megamaser Disk Galaxies
12192 James T. Lauroesch, University of Louisville Research Foundation, Inc. A SNAPSHOT Survey of Interstellar Absorption Lines
12203 S. Adam Stanford, University of California - Davis Rest Frame Optical Spectroscopy of Galaxy Clusters at 1.6 < z < 1.9
12209 Adam S. Bolton, University of Utah A Strong Lensing Measurement of the Evolution of Mass Structure in Giant Elliptical Galaxies
12210 Adam S. Bolton, University of Utah SLACS for the Masses: Extending Strong Lensing to Lower Masses and Smaller Radii
12215 Nancy R. Evans, Smithsonian Institution Astrophysical Observatory Searching for the Missing Low-Mass Companions of Massive Stars
12224 Naveen A. Reddy, National Optical Astronomy Observatory, AURA Measuring the Stellar Populations of Individual Lyman Alpha Emitters During the Epoch of Peak Star Formation
12238 William E. Harris, McMaster University Supermassive Star Clusters in Supergiant Galaxies: Tracing the Enrichment of the Earliest Stellar Systems
12248 Jason Tumlinson, Space Telescope Science Institute How Dwarf Galaxies Got That Way: Mapping Multiphase Gaseous Halos and Galactic Winds Below L*
12255 Trent J. Dupuy, Smithsonian Institution Astrophysical Observatory Probing Ultracool Atmospheres and Substellar Interiors with Dynamical Masses
12268 Ian U. Roederer, Carnegie Institution of Washington Production of the Heavy Elements in the Universe
12271 William B. Sparks, Space Telescope Science Institute Probing the Physics of Gas in Cool Core Clusters: Virgo
12272 Christy A. Tremonti, University of Wisconsin - Madison Testing Feedback: Morphologies of Extreme Post-starburst Galaxies
12275 Bart P. Wakker, University of Wisconsin - Madison Measuring gas flow rates in the Milky Way
12276 Bart P. Wakker, University of Wisconsin - Madison Mapping a nearby galaxy filament
12283 Matthew A. Malkan, University of California - Los Angeles WFC3 Infrared Spectroscopic Parallel Survey {WISP}: A Survey of Star Formation Across Cosmic Time
12289 J. Christopher Howk, University of Notre Dame A COS Snapshot Survey for z < 1.25 Lyman Limit Systems
12305 David Jewitt, University of California - Los Angeles Monitoring the Aftermath of an Asteroid Impact Event
12310 Goran Ostlin, Stockholm University LARS - The Lyman Alpha Reference Sample
12316 John P. Wisniewski, University of Washington HST/FGS Astrometric Search for Young Planets Around Beta Pic and AU Mic
12328 Pieter van Dokkum, Yale University 3D-HST: A Spectroscopic Galaxy Evolution Treasury Part 2

Selected highlights

GO 12061: Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey -- GOODS-South Field, Early Visits of SNe Search

Part of the GOODS/Chandra Deep Field South field, as imaged by HST CANDELS is one of three Multi-Cycle Treasury Program, whose observations will be executed over the next three HST Cycles. It builds on past investment of both space- and ground-based observational resources. In particular, it includes coverage of the two fields of the Great Observatory Origins Deep Survey (GOODS), centred on the northern Hubble Deep Field (HDF) in Ursa Major and the Chandra Deep Field-South in Fornax. In addition to deep HST data at optical and near-infrared wavelengths, the fields have been covered at X-ray wavelengths by Chandra (obviously) and XMM-Newton; at mid-infrared wavelengths with Spitzer; and ground-based imaging and spectroscopy using numerous telescopes, including the Kecks, Surbaru and the ESO VLT. This represents an accumulation of almost 1,000 orbits of HST time, and comparable scale allocations on Chandra, Spitzer and ground-based facilities. The CANDELS program is capitalising on this large investment, with new observations with WFC3 and ACS on both GOODS fields, and on three other fields within the COSMOS, EGS and UDS survey areas (see this link for more details). The prime aims of the program are twofold: reconstructing the history of galaxy formation, star formation and nuclear galactic activity at redshifts between z=8 and z=1.5; and searching for high-redshift supernovae to measure their properties at redshifts between z~1 and z~2. The program incorporates a tiered set of observations that complement, in areal coverage and depth, the deep UDF observations, while the timing of individual observations will be set to permit detection of high erdshift SNe candidates, for subsequent separate follow-up.

GO 12181: The Atmospheric Structure of Giant Hot Exoplanets

Probing the atmosphere of a transiting exoplanet The first exoplanet, 51 Peg b, was discovered through radial velocity measurements in 1995. 51 Pegb was followed by a trickle, and then a flood of other discoveries, as astronomers realised that there were other solar systems radically different from our own, where "hot jupiters" led to short-period, high-amplitude velocity variations. Then, in 1999, came the inevitable discovery that one of those hot jupiters. HD 209458b, was in an orbit aligned with our line of sight to the star, resulting in transits. Since that date, the number of known transiting exoplanet systems has grown to more than 100, most detected through wide-field photometric surveys with the Kepler satellite providing the highest sensitivity dataset. These transiting systems are invaluable, since they not only provide unambiguous measurements of mass and diameter, but they also provide an opportunity to probe the atmospheric structure by differencing spectra taken during and between primary secondary transit. Such observations are best done from space: indeed, the only successful atmospheric observations to date have been with HST and Spitzer. The present program aims to set these measurements on a systematic basis by targeting 13 transiting exoplanets. The WFC3-IR G141 grism will be used to search for characteristic near-infrared spectral features in those systems.

GO 12275: Measuring gas flow rates in the Milky Way

A map of the high velocity cloud systems surrounding the Milky Way (B. Wakker, U. Wisconsin). The stellar components of the Milky Way Galaxy are well known: the disk, the central bulge and the old, metal-poor stellar halo. However, the Milky Way is also surrounded by a halo of hot, gas that is itself embedded within a much more tenuous corona of even hotter, ionised gas. Within that structure lie high velocity clouds. Originally discovered in the 1930s as absorption features in stellar spectra, these clouds have velocities that differ significantly from the rotational velocity along that line of sight, and they are generally believed to be undergoing infall into the Galaxy. The origin and nature of these systems remains uncertain, with some favouring a Galactic origin, driven by star formation and feedback between disk and halo, and others supporting their origin within the warm-hot intergalactic medium. HVCs are not self luminous, so indirect methods need to be applied to examine their characteristics. The most effective is to identify stars that lie behind individual systems and, as with their discovery in the 1930s, search the stellar spectra for signature absorption lines produced by material within the cloud. Many, indeed most, of the key absorption features lie at ultraviolet wavelengths, a spectral region that has been opened up with the installation of the Cosmic Origins Spectrograph on HST. Detailed information is currently available for only five HVCs. The present program is using active galactic nuclei (AGNs) as background light sources to probe most of the remaining known HVCs within the Milky Way.

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