This week on HST


HST Programs: April 4, 2011 - April 10, 2011

Program Number Principal Investigator Program Title
11792 Peter McCullough, Space Telescope Science Institute Extrasolar Planet XO-2b
12016 Carol A Grady, Eureka Scientific Inc. The Stars and Edge-on Disks of PDS 144: An Intermediate-Mass Analog of Wide T Tauri Multiple Stars
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
12063 Sandra M. Faber, University of California - Santa Cruz Galaxy Assembly and the Evolution of Structure over the First Third of Cosmic Time - I
12099 Adam Riess, The Johns Hopkins University Supernova Follow-up for MCT
12161 David R. Ardila, Jet Propulsion Laboratory Accretion in Close Pre-Main-Sequence Binaries
12169 Boris T. Gaensicke, The University of Warwick The frequency and chemical composition of planetary debris discs around young white dwarfs
12176 Jonathan D. Nichols, University of Leicester Long term observations of Saturn's northern auroras
12177 Pieter van Dokkum, Yale University 3D-HST: A Spectroscopic Galaxy Evolution Treasury
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
12194 Mattia Negrello, Open University High resolution Near-Infrared imaging of the first sub-mm selected gravitational lens candidates in the Herschel ATLAS
12195 Masamune Oguri, National Astronomical Observatory of Japan (NAOJ) Understanding the Largest Quasar Lens SDSS J1029+2623
12220 Rupal Mittal, Rochester Institute of Technology Linking Star Formation with Intracluster Medium Cooling and AGN Heating in a Sample of Herchel Galaxy Clusters
12221 Ilaria Pascucci, University of Arizona The role of photoevaporation in clearing protoplanetary disks: mapping flows and determining mass flow rates
12228 Glenn Schneider, University of Arizona Probing for Exoplanets Hiding in Dusty Debris Disks: Inner {<10 AU} Disk Imaging, Characterization, and Exploration
12231 Paula Szkody, University of Washington An Unprecedented Opportunity to Follow 4 Accreting WDs into the Instabilty Strip
12253 Douglas Clowe, Ohio University Gravity in the Crossfire: Revealing the Properties of Dark Matter in Bullet-like Clusters
12277 Daniel E. Welty, University of Illinois at Urbana - Champaign HD 62542: Probing the Bare, Dense Core of an Interstellar Cloud
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}
12289 J. Christopher Howk, University of Notre Dame A COS Snapshot Survey for z < 1.25 Lyman Limit Systems
12299 Michael Eracleous, The Pennsylvania State University Spectroscopic Signatures of Binary and Recoiling Black Holes
12315 Hans Moritz Guenther, Smithsonian Institution Astrophysical Observatory Winds, accretion and activity: Deciphering the FUV lines in TW Hya
12324 C. S. Kochanek, The Ohio State University The Temperature Profiles of Quasar Accretion Disks
12328 Pieter van Dokkum, Yale University 3D-HST: A Spectroscopic Galaxy Evolution Treasury Part 2
12447 Andrew S. Fruchter, Space Telescope Science Institute The Nature of the Remarkable Transient GRB 110328A

Selected highlights

GO 12099: Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey - SNe follow-up

High redshift supernovae from HST observations in previous cycles 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 redshift SNe candidates, for subsequent separate follow-up. The present observations target a high-redshift supernova identified in the course of the survey imaging.

GO 12161: Accretion in Close Pre-Main-Sequence Binaries

Wide-field image, from NOAO, of the young binary star, T Tauri, and its immediate environs Young stars retain dense, dust and gas-rich circumstellar disks during the earliest stages of their formation and evolution. Observations of clusters and young associations suggest that these disks are present for at least the first 10 Myrs of the star's existence during which time the stars are generally given the T tauri classification. During this phase, there is substantial accretion of material onto the central star, leading to heating of the inner regions of the accretion disk, and significant emission at ultraviolet and X-ray wavelengths. Close binary stars are no exception to this paradigm, but the dynamics of the system tend to strongly truncate the individual circumstellar disks, but also lead to the formation of a large, circumbinary disk of material surrounding both stars. Previous HST programs (e.g. GO 10840 ; GO 11616 ) have used the STIS and the ACS/SBC to investigate accretion processes at FUV wavelengths in(primarily) single T Tauria. The present program will use COS to extend those investigations to the known binaries DQ Tau and UZ Tau E. COS will be used to measure the emission profiles of an extensive number of lines, probing opacities, temperatures and densities in the disk and outflow regions, and testing models for the magnetic structrue and accretion flows in young binary systems.

GO 12187: A New Sample of Circumnuclear Gas Disks for Measuring Black Hole Masses in Spiral Galaxies

Schematic diagram of an active galacioc nucleus Active galaxies are characterised by bright, compact nuclei that are the source of strong emission lines due highly ionised material. These phenomena are generally believed to arise in hot gas in an accretion disk, centred on a massive (>106 solar mass) hole; indeed, detailed kinematics for a handful of objects have confirmed the presence of a compact, massive object in the core. Most active galactic nuclei (AGNs) are found in spiral galaxies that possess at least a moderately prominent bulge, and there appears to be a clear correlation between the mass of the central black hole and the velocity dispersion of the bulge. Morphologically, the majority of galaxies currently known to harbour black holes are early-type systems, predominantly ellipticals. The present proposal aims to redress this balance by following up on a survey of lenticular and spiral galaxies, where the ACS was used to search for evidence for H-alpha emission from circumbuclear accretion disks. Six promising targets were identified, and the present proposal will use STIS to obtain high spatial resolution spectra of those systems. The data will be used to determine the masses of the central black holes, and probe the dynamics of the bulge systems in these later-type galaxies.

GO 12447: The Nature of the Remarkable Transient GRB 110328A

Artist's impression of a gamma-ray burst Gamma ray bursts are events that tap extraordinary energies (1045 to 1047 joules) in remarkably short periods of time. Several thousands bursts have been detected over the last 30+ years, and analyses indicate that they (or, at least the majority of the sample) can be divided into two classes with durations longer or shorter than 2 seconds. The short bursts appear to release more high energy radiation, so the two subsets are known as long/soft and short/hard bursts.The short/hard bursts appear to arise from coalescing binary systems (probably pairs of neutron stars or black holes), but the long/soft bursts appear to originate in the collapse of very massive stars. The latter sources are therefore almost certainly associated with star formation, so they act as signposts to active star-forming regions in the high redshift universe. Not all GRBs fall into these two categories, however. In particular, the present program targets a GRB, originally detected on March 28th, that is exhibiting unusual behaviour. The original burst, detected by the Swift satellite, lasted for ~1,000 seconds (well into the "long" regime), and Swift identified a corresponding X-ray source whose brightness rose during the burst. Since then, the source has triggered the gamma-ray detector of Swift at least twice. This recurrent behaviour is not unexpected for a Galactic source (multiple accretion events, for example), but ground-based observations have shown that that source is coincident with a galaxy at z=0.35. Archival searches through data obtainedby the Palomar Transit factory indicate that an optical transient has been detected at this location in the past. The present observations with HST are aimed at obtaining high spatial-resolution imaging to search for an optical counterpart.

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