This week on HST


HST Programs: September 17 - September 23, 2007

Program Number Principal Investigator Program Title Links
10766 Andreas Zezas, Smithsonian Institution Astrophysical Observatory A Deep X-ray Survey of the Small Magellanic Cloud Abstract
10787 Jane Charlton, The Pennsylvania State University Modes of Star Formation and Nuclear Activity in an Early Universe Laboratory Abstract
10789 Christopher J. Conselice, University of Nottingham The Role of Environment in the Formation of Dwarf Galaxies Abstract
10840 Nuria Calvet, University of Michigan The FUV fluxes of Tauri stars in the Taurus molecular cloud Abstract
10872 Harry Teplitz, California Institute of Technology Lyman Continuum Emission in Galaxies at z=1.2 Abstract
10915 Julianne Dalcanton, University of Washington ACS Nearby Galaxy Survey Abstract
10919 Edward F. Guinan, Villanova University Eclipsing Binaries in the Local Group: II - Calibration of the Zeropoint of the Cosmic Distance Scale and Fundamental Properties of Star Abstract
11079 Luciana Bianchi, The Johns Hopkins University Treasury Imaging of Star Forming Regions in the Local Group: Complementing the GALEX and NOAO Surveys Abstract
11081 Gisella Clementini, INAF, Osservatorio Astronomico di Bologna RR Lyrae stars in M31 Globular Clusters: How did the M31 Spiral Galaxy Form? Abstract
11082 Christopher Conselice, Univ. of Nottingham NICMOS Imaging of GOODS: Probing the Evolution of the Earliest Massive Galaxies, Galaxies Beyond Reionization, and the High Redshift Obscured Universe Abstract
11084 Dan Zucker, Institute of Astronomy, Cambridge Probing the Least Luminous Galaxies in the Local Universe Abstract
11107 Timothy M. Heckman, The Johns Hopkins University Imaging of Local Lyman Break Galaxy Analogs: New Clues to Galaxy Formation in the Early Universe Abstract
11122 Bruce Balick, University of Washington Expanding PNe: Distances and Hydro Models Abstract
11124 David V. Bowen, Princeton University The Origin of QSO Absorption Lines from QSOs Abstract
11134 Karen Knierman, University of Arizona WFPC2 Tidal Tail Survey: Probing Star Cluster Formation on the Edge Abstract
11175 Sandra M. Faber, University of California - Santa Cruz UV Imaging to Determine the Location of Residual Star Formation in Galaxies Recently Arrived on the Red Sequence Abstract
11178 William M. Grundy, Lowell Observatory Probing Solar System History with Orbits, Masses, and Colors of Transneptunian Binaries Abstract
11222 Michael Eracleous, The Pennsylvania State University Direct Detection and Mapping of Star Forming Regions in Nearby, Luminous Quasars Abstract
11224 Margarita Karovska, Smithsonian Institution Astrophysical Observatory Unraveling Mira AB Accretion Mysteries Abstract
11229 Margaret Meixner, Space Telescope Science Institute SEEDS: The Search for Evolution of Emission from Dust in Supernovae with HST and Spitzer Abstract

Some selected highlights

GO 10872: Lyman Continuum Emission in Galaxies at z=1.2

Lyman alpha image of the radio galaxy, 4C41.17 In Big Bang cosmology, the early history of the unverise is characterised by three distinct phases: the initial expansion, during which time Big Bang nucleosynthesis occurs, and the universe cools from its initial exceedingly high temperatures; recombination, which occurs at a redshift z~1,100 (or an age of ~400,000 years), when the Universe was cool enough to allow neutral hydrogen to become dominant, leading to high opacity and the cosmic microwave background; and reionisation, when energy sources reionised hydrogen, reducing the opacity of the intergalactic medium and restoring transparency. Reionisation is generally believed to have occurred at a redshift between z~6 and z~20, with the ionising sources either (or both) the first generation of stars (Population III starbursts) and/or proto-quasars. The IGM remains ionised thereafter. A key issue in developing an understanding of this process is assessing how readily starburst-generated Lyman-alpha emission escapes from galaxies, and how starbursts contribute to reionisation at intermediate redshifts. This proposal aims to quantify this matter by targeting galaxies at redshifts 1 < z < 2 for observations at ultraviolet wavelengths with the Advanced Camera for Surveys Solar Blind Channel (ACS/SBC).

GO 11082: NICMOS Imaging of GOODS: Probing the Evolution of the Earliest Massive Galaxies, Galaxies Beyond Reionization, and the High Redshift Observational Universe

ACS images of a section of the GOODS fields The Great Observatories Origins Deep Survey, is a large-scale program that is designed to probe galaxy formation and evolution at redshifts from z~1 to z~6. GOODS covers two ~150 sq. arcminute fields, one centred on the Hubble Deep Field and the second on the Chandra Deep Field South, and combines deep oppical/far-red imaging (F435W, F606W, F775W and F850LP filters) using ACS on HST with deep IRAC (3.6 to 8 micron) and MIPS (25 micron) imaging with Spitzer. Chandra data are also available for the bulkd of the field. The present program is supplementing those data with near-infrared H-band (F160W) imaging with NICMOS, coupled (eventually) with parallel ultraviolet observations using the ACS/SBC.

GO 11229: The Search for Evolution of Emission from Dust in Supernovae with HST and Spitzer

Supernova 1987A in the LMC, an HST image acquired by WFPC2 in 1998 Type II supernovae are produced by core collapse in stars exceeding ~7 solar masses. These massive stars support a complex series of nuclear reactions on the main sequence, ranging from hydrogen fusion near the surface to silicon reactions that build up the iron core. This produces an internal onion-ring structure, with a wide range of chemical species that are blasted into the interstellar medium when the core exceeds the Chandrasekhar mass an implodes. These supernovae are widely hypothesised as a potent source of interstellar dust, with the material condesning within the cooling ejecta. However, observations have so far provided only lukewarm support for these theoretical expectations. This proposal combines optical and near-infrared HST observations of recent type II supernovae, using WFPC2 and NICMOS, respectively, with mid-infrared imaging with IRAC and MIPS on Spitzer. The aim is to use the multiwavelength imaging to probe the evolution of the dust content in the surrounding ejecta. NICMOS observations of SN2006BC in NGC 2397.

Past weeks:
page by Neill Reid, updated 10/8/2007