This week on HST

HST Programs: November 20 - November 26, 2006

Program Number Principal Investigator Program Title Links
9970 Edward F. Guinan, Villanova University The Best Brown Dwarf Yet?: FGS Astrometry of the Companion to the Hyades Eclipsing Binary V471 Tau Abstract
10475 Nathan Smith, University of Colorado at Boulder An ACS H-alpha Survey of the Carina Nebula Abstract
10481 Howard E. Bond, Space Telescope Science Institute HST Observations of Astrophysically Important Visual Binaries Abstract
10494 Leon Koopmans, Kapteyn Institute Imaging the mass structure of distant lens galaxies Abstract
10556 David Turnshek, University of Pittsburgh Neutral Gas at Redshift z=0.5 Abstract
10787 Jane Charlton, The Pennsylvania State University Modes of Star Formation and Nuclear Activity in an Early Universe Laboratory Abstract
10800 Keith Noll, Space Telescope Science Institute Kuiper Belt Binaries: Probes of Early Solar System Evolution Abstract
10802 Adam Riess, Space Telescope Science Institute SHOES-Supernovae, HO, for the Equation of State of Dark energy Abstract
10808 Pieter van Dokkum, Yale University Morphologies of spectroscopically-confirmed red and dead galaxies at z~2.5 Abstract
10817 Hsiao-Wen Chen, University of Chicago Unveiling Starburst Morphology of Distant Damped Ly-alpha Galaxies Hosting Gamma-Ray Bursts Abstract
10833 Bradley Peterson, The Ohio State University Research Foundation Host Galaxies of Reverberation Mapped AGNs Abstract
10849 Stanimir Metchev, University of California - Los Angeles Imaging Scattered Light from Debris Disks Discovered by the Spitzer Space Telescope around 21 Sun-like Star Abstract
10852 Glenn Schneider, University of Arizona Coronagraphic Polarimetry with NICMOS: Dust grain evolution in T Tauri stars Abstract
10860 Michael Brown, California Institute of Technology The largest Kuiper belt objects Abstract
10861 David Carter, Liverpool John Moores University An ACS Treasury Survey of the Coma cluster of galaxies Abstract
10874 Wei Zheng, The Johns Hopkins University Search for Extremely Faint z>7 Galaxy Population with Cosmic Lenses Abstract
10886 Adam Bolton, Smithsonian Institution Astrophysical Observatory The Sloan Lens ACS Survey: Towards 100 New Strong Lenses Abstract
10890 Arjun Dey, National Optical Astronomy Observatories Morphologies of the Most Extreme High-Redshift Mid-IR-Luminous Galaxies Abstract
10906 Sylvain Veilleux, University of Maryland The Fundamental Plane of Massive Gas-Rich Mergers: II. The QUEST QSOs Abstract
10915 Julianne Dalcanton, University of Washington ACS Nearby Galaxy Survey Abstract
10920 Charles Hoopes, The Johns Hopkins University High-Resolution Imaging of Nearby Lyman Break Galaxy Analogs in the GALEX All-Sky Survey Abstract
10921 C. O'Dell, Vanderbilt University Tangential Velocities of Objects in the Orion Nebula and Locating the Embedded Outflow Sources Abstract
10929 Todd Henry, Georgia State University Research Foundation Calibrating the Mass-Luminosity Relation at the End of the Main Sequence Abstract
10989 George Benedict, University of Texas at Austin Astrometric Masses of Extrasolar Planets and Brown Dwarfs Abstract
11003 Lori M. Lubin, University of California - Davis Mixing It Up : Gas, Stars, Starbirth, and AGN in a Supercluster at z = 0.9 Abstract
11011 C. S. Kochanek, The Ohio State University Research Foundation Dissecting An Accretion Disk Abstract

Some selected highlights

GO 10475: An ACS H-alpha Survey of the Carina Nebula

HST image of NGC 3372, the Carina nebula The Carina nebula, or NGC 3372, is a young, star-forming region lying at a distance of ~2 kpc in the southern Milky Way. The presemt program is surveying much of the nebula with ACS and WFPC2, using narrow-passband filters centred on or near H-alpha. Carina provides an important link between well-studied nearby star-forming regions like Orion, and more distant mini-starbusts like 30 Doradus. The present observations will permit a census of microjets, proplyds, and silhouette disks with diameters as small as 200 AU, besides providing the first catalog of outflows (jets) from embedded low-mass stars, thin filamentary shocks, and wind-wind collisions in Carina.

GO 10808: Morphologies of spectroscopically-confirmed red and dead galaxies at z~2.5

Composite image from NICMOS near-infrared data on the Hubble Deep Field Identifying the initial epoch of galaxy formation is a fundamental question facing cosmology in the 21st century. Direct observation of `first light' galaxies is one of the four planks underlying the prime science program of the James Webb Space Telescope. In the meantime, HST can probe this issue through galactic archaeology of lower redshift galaxies (bearing in mind that many of these `lower redshifts' would be regarded as `extrelely high redshift' 10 years ago). Thus, the present program aims to use NICMOS to obtain images of candidate proto-ellipticals, identified from previous near-infrared imaging and spectroscopic observations. All of the targets are red, lack any evidence for emission lines and have strong Balmer/4000 breaks; this suggests that there is little, if any, on-going star formation, and the underlying stellar populations are well evolved. The NICMOS observations will allow detailed study of the morphology of these old systems, and an assessment of whether giant ellipticals were still assembling at z~2.5.

GO 10852: Coronagraphic Polarimetry with NICMOS: Dust grain evolution in T Tauri stars

NICMOS coronagraphic images of GM Aurigae, showing the circumstellar disk The T Tauri phase 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. It is generally agreed that at least giant planet formation occurs during this phase, terminating when the gas dissipates to leave a dusty debris disk. The properties of the resultant planets are likely to depend strongly on the properties of the dust within the circumstellar disk. This program aims to combine coronagraphy with the polarimetric capabilities of NICMOS, HST's near-infrared camera, to study the size distribution of dust particles within the disks surrounding a representative sample of young stellar objects. The forthcoming set of observations will target GM Aurigae, a ~0.8 solar-mass star with an age between 2 and 10 million years that has a substantial circumstellar disk. Multiwavelength measurements strongly suggest that the disk, which likely has a full diameter of ~600 AU, has a central gap, radius ~4 AU; that gap may well have been cleared by a jovian-mass planet.

GO 10915: ACS Nearby Galaxy Survey

Ground-based image of M81 (from M. Motoki's astrophotodiary) Colour-magnitude diagrams derived from photometric surveys have proven invaluable in achieving an understanding of the main properties of the galactic stellar populations. Large ground-based telescopes allowed extension of this type of analysis to the principal satellites of the Milky Way and, to a limited extent, the Andromeda spiral. With the advent of HST, particularly following SM3B and the installation of the Advance Camera for Surveys, those fundamental CMD studies can be extended to higher-density star fields, fainter magnitudes and intrinsically lower luminosity stars. Until recently, those studies have concentrated on Local Group galaxies; the ambitious aim of the current program is to conduct a systematic survey of all major star-forming galaxies within ~3.5Mpc of the Milky Way, together with a number of galaxies in the M81 group at a distance of ~4 Mpc. The program includes a total of 45 galaxies, ranging from massive spiral systems to dwarf galaxies. The observations are being made using the wide-field camera on ACS, sampling selected fields in the wide-V (F606W) and I (F814W) passbands. Observations of M81 are scheduled during the coming week.

Past weeks:
page by Neill Reid, updated 27/10/2006