This week on HST


HST Programs: June 27, 2011 - July 3, 2011

Program Number Principal Investigator Program Title
12071 Julianne Dalcanton, University of Washington A Panchromatic Hubble Andromeda Treasury - I
12073 Julianne Dalcanton, University of Washington A Panchromatic Hubble Andromeda Treasury - I
12099 Adam Riess, The Johns Hopkins University Supernova Follow-up for MCT
12166 Harald Ebeling, University of Hawaii A Snapshot Survey of The Most Massive Clusters of Galaxies
12168 Boris T. Gaensicke, The University of Warwick The temperature, mass and chemical composition of the bare ONe white dwarf SDSS1102+4054
12169 Boris T. Gaensicke, The University of Warwick The frequency and chemical composition of planetary debris discs around young white dwarfs
12177 Pieter van Dokkum, Yale University 3D-HST: A Spectroscopic Galaxy Evolution Treasury
12181 Drake Deming, University of Maryland The Atmospheric Structure of Giant Hot Exoplanets
12187 Luis C. Ho, Carnegie Institution of Washington A New Sample of Circumnuclear Gas Disks for Measuring Black Hole Masses in Spiral Galaxies
12192 James T. Lauroesch, University of Louisville Research Foundation, Inc. A SNAPSHOT Survey of Interstellar Absorption Lines
12198 Jessica L. Rosenberg, George Mason University Unravelling the Mysteries of the Leo Ring: An Absorption Line Study of an Unusual Gas Cloud
12204 Christopher Thom, Space Telescope Science Institute Probing the Ionized Gas in the Magellanic Stream
12212 D. Michael Crenshaw, Georgia State University Research Foundation What are the Locations and Kinematics of Mass Outflows in AGN?
12248 Jason Tumlinson, Space Telescope Science Institute How Dwarf Galaxies Got That Way: Mapping Multiphase Gaseous Halos and Galactic Winds Below L*
12253 Douglas Clowe, Ohio University Gravity in the Crossfire: Revealing the Properties of Dark Matter in Bullet-like Clusters
12258 Karl D. Gordon, Space Telescope Science Institute The Environmental Dependence of Ultraviolet Dust Extinction Curves in the Small Magellanic Cloud
12263 Toru Misawa, Shinshu University Three Dimensional Mapping of the Magellanic Bridge by High-Resolution Spectroscopy toward Multiple Sightlines
12269 Claudia Scarlata, University of Minnesota - Twin Cities The escape of Lya photons in star-forming galaxies
12275 Bart P. Wakker, University of Wisconsin - Madison Measuring gas flow rates in the Milky Way
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, University of Missouri - Columbia Hubble Infrared Pure Parallel Imaging Extragalactic Survey {HIPPIES}
12371 Jane R. Rigby, NASA Goddard Space Flight Center Does the brightest lensed galaxy contain an AGN?
12436 Mark R. Showalter, SETI Institute New Horizons Mission Planning Support: A Deep Search for Faint Rings of Pluto
12675 Keith S. Noll, Space Telescope Science Institute Hubble Heritage: 1, 000, 000th Science Exposure and Neptune's First Orbit

Selected highlights

GO 12071: 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 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 12204: Probing the Ionized Gas in the Magellanic Stream

The Large Magellanic Cloud (upper left) with the Small Magellanic Cloud (right) and the (foreground) Galactic globular cluster47 Tucanae The Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC) are the most massive satellites of the Milky Way galaxy. The relative motions of these gas-rich systems has led to signficant dynamical interactions, which may well have led to corresponding star formation episodes in the three systems. In particular, the well known Magellanic Stream, stretching between the two Clouds, is thought to be a product either of interactions between the Clouds, or of ram-stripping of gas from the LMC on its last passage through the Plane of the Milky Way. The present program aims to probe the chemical composition, temperature and density distribution of the Magellanic Stream through ultraviolet spectroscopy of background QSOs. A set of three tightly clustereed quasars have been selected for observations with the Cosmic Origins Spectrograph. Two of these QSOs will be viewed on lines of sight that pass through the ionised gas of the halo; the third lies behind neutral gas in the Magellanic Stream. The COS observations will permit measurement of the line of sight gas structure in these different environments.

GO 12286: Hubble Infrared Pure Parallel Imaging Extragalactic Survey, HIPPIES

The ACS optical/far-red image of the Hubble Ultra Deep Field Galaxy evolution in the early Universe is a discipline of astronomy that has been transformed by observations with the Hubble Space Telescope. The original Hubble Deep Field, the product of 10 days observation in December 1995 of a single pointing of Wide Field Planetary Camera 2, demonstrated conclusively that galaxy formation was a far from passive process. The images revealed numerous blue disturbed and irregular systems, characteristic of star formation in galaxy collisions and mergers. Building on this initial progam, the Hubble Deep Field South (HDFS) provided matching data for a second southern field, allowing a first assessment of likely effects due to field to field cosmic variance, and the Hubble Ultra-Deep Field (UDF) probed to even fainter magitude with the Advanced Camera for Surveys (ACS). The highest redshift objects found in the UDF have redshifts approaching z~7. Pushing to larger distances, and greater ages, demands observatons at near-infrared wavelengths, as the characteristics signatures of star formation are driven further redward in the spectrum. Wide Field Camera 3, installed in Servicing Mission 4, is well suited to these observations, and a number of programs are in place in Cycle 17 that address these issues. Indeed, WFC3 is employed in pure parallel mode by several programs. These take advantage of other science programs, usually with COS, that involve 2-5 orbit pointings on sources at high galactic latitude. The WFC3 pointing is unplanned, since it depends on the orientation adopted for the prime observations, but 2-5 orbits of IR imaging can reach galaxies at redshifts exceeding z=7 (potentially even z~8) in high latitude fields. This is one of two such programs in the cycle 17 portfolio.

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