This week on HST


HST Programs: November 14, 2011 - November 20, 2011


Program Number Principal Investigator Program Title
11535 James C. Green, University of Colorado at Boulder COS-GTO: Deep Search for an Oxygen Atmosphere on Callisto
12067 Marc Postman, Space Telescope Science Institute Through a Lens, Darkly - New Constraints on the Fundamental Components of the Cosmos
12099 Adam Riess, The Johns Hopkins University Supernova Follow-up for MCT
12101 Marc Postman, Space Telescope Science Institute Through a Lens, Darkly - New Constraints on the Fundamental Components of the Cosmos
12103 Marc Postman, Space Telescope Science Institute Through a Lens, Darkly - New Constraints on the Fundamental Components of the Cosmos
12166 Harald Ebeling, University of Hawaii A Snapshot Survey of The Most Massive Clusters of Galaxies
12172 Claus Leitherer, Space Telescope Science Institute Is the Extraordinary Super Star Cluster NGC 3125-1 an Imposter?
12177 Pieter van Dokkum, Yale University 3D-HST: A Spectroscopic Galaxy Evolution Treasury
12192 James T. Lauroesch, University of Louisville Research Foundation, Inc. A SNAPSHOT Survey of Interstellar Absorption Lines
12211 Nuria Calvet, University of Michigan Are Weak-Line T Tauri Stars Still Accreting?
12248 Jason Tumlinson, Space Telescope Science Institute How Dwarf Galaxies Got That Way: Mapping Multiphase Gaseous Halos and Galactic Winds Below L*
12250 John Bally, University of Colorado at Boulder Irradiated Jets and Proplyds in NGC 1977, Orion Nebula's Cousin
12254 Adrienne Cool, San Francisco State University Helium-core White Dwarfs and Cataclysmic Variables in NGC 6752: New Clues to the Dynamical Evolution of Globular Clusters
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
12310 Goeran Oestlin, Stockholm University LARS - The Lyman Alpha Reference Sample
12320 Brian Chaboyer, Dartmouth College The Ages of Globular Clusters and the Population II Distance Scale
12360 Saul Perlmutter, University of California - Berkeley Cosmology From Cluster-Hosted and z>1 Supernovae Orphaned from the MCT Program
12378 Andrew J. Levan, The University of Warwick The differing environments of dark gamma-ray bursts
12446 Michael Shara, American Museum of Natural History Ionization and Light Echoes in the T Pyxidis Nebula
12448 Arlin Crotts, Columbia University in the City of New York Towards a Detailed Understanding of T Pyx, Its Outbursts and Shell
12461 Adam Riess, The Johns Hopkins University Supernova Follow-up for MCT
12488 Mattia Negrello, Open University SNAPshot observations of gravitational lens systems discovered via wide-field Herschel imaging
12508 Theodore R. Gull, NASA Goddard Space Flight Center Constraining the evolutionary state of the hot, massive companion star and the wind-wind collision region in Eta Carinae
12515 Dougal Mackey, Australian National University Probing the outer limits of a galactic halo - deep imaging of exceptionally remote globular clusters in M31
12520 Charles R. Proffitt, Computer Sciences Corporation Testing Rotational Mixing in Massive Stars: Boron in the Galactic Open Cluster NGC 3293
12533 Crystal Martin, University of California - Santa Barbara Escape of Lyman-Alpha Photons from Dusty Starbursts
12557 Kayhan Gultekin, University of Michigan Low-Mass Black Holes and CIV in Low-Luminosity AGN
12601 Laurent Lamy, Observatoire de Paris - Section de Meudon HST STIS/ACS observations of the aurorae of Uranus during active solar wind conditions
12658 John M. Cannon, Macalester College Fundamental Parameters of the SHIELD Galaxies
12674 Robert A. Fesen, Dartmouth College A Deep Kinematic Investigation of Cas A's Opposing High-Velocity Ejecta Jets

Selected highlights

GO 12067: Through a Lens, Darkly - New Constraints on the Fundamental Components of the Cosmos


The cluster MACS J1206.2-0.47, imaged by HST as part of the CLASH program
The overwhelming majority of galaxies in the universe are found in clusters. As such, these systems offer an important means of tracing the development of large-scale structure through the history of the universe. Moreover, as intense concentrations of mass, galaxy clusters provide highly efficient gravitational lenses, capable of concentrating and magnifying light from background high redshift galaxies to allow detailed spectropic investigations of star formation in the early universe. Hubble imaging has already revealed lensed arcs and detailed sub-structure within a handful of rich clusters. At the same time, the lensing characteristics provide information on the mass distribution within the lensing cluster. The present program aims to capitalise fully on HST's imaging capabilities, utilising the refurbished Advanced Camera for Surveys and the newly-installed Wide-Field Camera 3 to obtain 17-colour imaging of 25 rich clusters. The data will be use to map the mass profiles of the clusters and probe the characteristics of the high-redshift lensed galaxies. Since ACS and WFC3 can be operated in parallel, the program will also use parallel imaging in offset fields to search for high-redshift supernovae. The present observations target the cluster MACS 0744+3927 at z=0.686

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 12211: Are weak-line T Tauri stars still accreting

Schematic view of a T Tauri star The T Tauri stage of evolution occurs early in a star's lifetime, within ~10 Myrs of its birth, when it still retains a dense, dust and gas-rich circumstellar disk. During this phase, there is significant accretion of material onto the central star. This leads to heating of the inner regions of the accretion disk, and significant emission at ultraviolet and X-ray wavelengths. T Tauris are classified into four main categories, which are generally believed to form an evolutionary sequence: classical T Tauri stars, which exihibit strong emission lines and strong infrared excess and are still accreting significant material from substantial circumstellar disks; weak-lined T tauris, which, as the name implies, have significantly weaker emission lines; naked T tauri stars, which lack substantial line emission and any significant infrared excess; and post-T tauri stars, which are late-type stars that are well separated from any star orming regions, but which are lkely to have ages between 10 and 100 million years. The aim of this proposal is to use low-resolution spectroscopic observations with the ACS Solar Blind Channel (ACS/SBC) to probe the gaseous content of a sample of 13 weak-lined T Tauri stars.

GO 12446: Ionization and Light Echoes in the T Pyxidis Nebula

Artist's impression of the recurrent nova, RS Oph (by David Hardy) Recurrent novae are generally agreed to be close binary systems, comprising a white dwarf and a companion main sequence star that is overflowing its Roche lobe, leading to period transfers of mass onto the white dwarf surface. The mass transfer episode triggers nuclear ractions, which lead the star increasing significantly in it luminosity. T Pyxidis is one such system, and it exhibited fairly regular outbursts every 20 years between its discovery, in 1890, and 1966. Since then, however, it has been dormant, a prolonged period of quiescence that led to suggestions, earlier this year, that it might either be headed for hibernation, or in the process of accumulating sufficient mass to trigger a type Ia supernova explosion (in about 1 million years). Perhaps prompted by these suggestions (a la Monty Python Mary Queen of Scots radio sketch), T Pyxidis erupted into activity on or around April 15th. A first set of observation with HST, designed to obtain H-alpha images of the illuminated ejecta, were obtained on April 18th, with subsequent images taken on April 30th, a third set on July 8th and a fourth on September 25. Additional observations will be obtained early next year with the aim of tracing the development of any light echoes. In addition, program GO 12448 is obtaining complementary spectroscopic and multiband imaging observations to enable a thorough analysis of the event.
Past weeks:
page by Neill Reid, updated 10/11/2011