This week on HST

HST Programs: December 21 - December 27, 2009

Program Number Principal Investigator Program Title Links
10897 Michael Liu, University of Hawaii Coronagraphic imaging of the submillimeter debris disk of a 200Myr old M-dwarf Abstract
11138 Eric S. Perlman, Florida Institute of Technology The Physics of the Jets of Powerful Radio Galaxies and Quasars Abstract
11202 Leon Koopmans, Kapteyn Astronomical Institute The Structure of Early-type Galaxies: 0.1-100 Effective Radii Abstract
11235 Jason A. Surace, California Institute of Technology HST NICMOS Survey of the Nuclear Regions of Luminous Infrared Galaxies in the Local Universe Abstract
11360 Robert W. O'Connell, The University of Virginia Star Formation in Nearby Galaxies Abstract
11520 James Green, University of Colorado COS-GTO: QSO Absorbers, Galaxies and Large-scale Structures in the Local Universe Abstract
11522 James Green, University of Colorado COS-GTO: STAR FORMATION/LYMAN-ALPHA Abstract
11541 James Green, University of Colorado COS-GTO: COOL, WARM AND HOT GAS IN THE COSMIC WEB AND IN GALAXY HALOS Abstract
11568 Seth Redfield, Wesleyan University A SNAPSHOT Survey of the Local Interstellar Medium: New NUV Observations of Stars with Archived FUV Observations Abstract
11588 Raphael Gavazzi, CNRS, Institut d'Astrophysique de Paris Galaxy-Scale Strong Lenses from the CFHTLS survey Abstract
11594 John M. O'Meara, Saint Michaels College A WFC3 Grism Survey for Lyman limit absorption at z=2 Abstract
11606 Dan Batcheldor, Rochester Institute of Technology Dynamical Hypermassive Black Hole Masses Abstract
11625 Ivan Hubeny, University of Arizona Beyond the classical paradigm of stellar winds: Investigating clumping, rotation and the weak wind problem in SMC O stars Abstract
11643 Ann Zabludoff, University of Arizona A Timeline for Early-Type Galaxy Formation: Mapping the Evolution of Star Formation, Globular Clusters, Dust, and Black Hole Abstract
11644 Michael E. Brown, California Institute of Technology A dynamical-compositional survey of the Kuiper belt: a new window into the formation of the outer solar system Abstract
11653 Robert Kirshner, Harvard University SAINTS - Supernova 1987A INTensive Survey Abstract
11666 Adam J. Burgasser, Massachusetts Institute of Technology Chilly Pairs: A Search for the Latest-type Brown Dwarf Binaries and the Prototype Y Dwarf Abstract
11670 Peter Garnavich, University of Notre Dame The Host Environments of Type Ia Supernovae in the SDSS Survey Abstract
11696 Matthew A. Malkan, University of California - Los Angeles Infrared Survey of Star Formation Across Cosmic Time Abstract
11697 Slawomir Stanislaw Piatek, New Jersey Institute of Technology Proper Motion Survey of Classical and SDSS Local Group Dwarf Galaxies Abstract
11700 Michele Trenti, University of Colorado at Boulder Bright Galaxies at z>7.5 with a WFC3 Pure Parallel Survey Abstract
11712 John P. Blakeslee, Dominion Astrophysical Observatory Calibration of Surface Brightness Fluctuations for WFC3/IR Abstract
11714 Howard E. Bond, Space Telescope Science Institute Snapshot Survey for Planetary Nebulae in Local Group Globular Clusters Abstract
11718 Julianne Dalcanton, University of Washington The Stellar Halos of Dwarf Galaxies Abstract
11720 Patrick Dufour, University of Arizona Detailed analysis of carbon atmosphere white dwarfs Abstract
11726 Edward F. Guinan, Villanova University Mysteries of the North Star: HST/COS confirmation of real-time evolution and upper atmospheric heating in Polaris Abstract
11727 Timothy M. Heckman, The Johns Hopkins University UV spectroscopy of Local Lyman Break Galaxy Analogs: New Clues to Galaxy Formation in the Early Universe Abstract
11730 Nitya Jacob Kallivayalil, Massachusetts Institute of Technology Continued Proper Motions of the Magellanic Clouds: Orbits, Internal Kinematics, and Distance Abstract
11741 Todd Tripp, University of Massachusetts Probing Warm-Hot Intergalactic Gas at 0.5 < z < 1.3 with a Blind Survey for O VI, Ne VIII, Mg X, and Si XII Absorption Systems Abstract
11782 Oleg Y. Gnedin, University of Michigan Measuring the Shape and Orientation of the Galactic Dark-Matter Halo using Hypervelocity Stars Abstract
11788 George Fritz Benedict, University of Texas at Austin The Architecture of Exoplanetary Systems Abstract
11791 C. S. Kochanek, The Ohio State University Research Foundation /td> The Wavelength Dependence of Accretion Disk Structure Abstract
11803 Holland Ford, The Johns Hopkins University Observing Cluster Assembly Around the Massive Cluster RXJ0152-13 Abstract

Selected highlights

GO 11594: A WFC3 Grism Survey for Lyman limit absorption at z=2

HRC grism image of SN 1987A, as displayed in the Hubble Legacy Archive Grisms are optical components with finely ruled gratings that canbe introduced into the beam of an imaging camera to produce low-resolution spectra of objects within the field of view. Wide Field Camera 3 on HST has three such components: an ultraviolet grism, G280, providing spectroscopy from ~2100 to 3900 Angstroms; and two grisms, G102 and G141, for use at near-infrared wavelengths. The present program aims to use the UV grism to search for galaxies at redshifts in the range 1.8 < z < 2.5. The observations target 64 quasars, drawn from the Sloan Digital Sky Survey, that have absorption features that are characteristic of that redshift range. Those features are likely due to foreground galaxies, whose extended gaseous halos absorb light from the QSO. The grism data will used to search for sources with emission lines that indciate that they are at the appropriate redshift.

GO 11653: SAINTS - Supernova 1987A INTensive Survey

November 2003 HST image of the SN1987A gaseous ring SN1987A, in the Large Magellanic Cloud, is (as far as we know) the nearest supernova to the Sun since Kepler's supernova of 1604. While its eruption, in January 1987, predated HST's launch by over 3 years, the remnant has been a regular observational target since the installation of COSTAR at the first servicing mission. Those high resolution observations have revealed the development, and evolution, of extensive, intricate structures as the blast wave from SN1987A encounters the surrounding interstellar medium. In particular, a striking circum-remnant ring has developed, with numerous hot spots stimulated by the fastest moving debris. The present HST program continues to monitor the development of those features, using a series of observations with WFC3/UVIS that are co-ordinated with the Chandra X-ray Observatory. Over the past few cycles, the hotspots are fusing as the shock fully enters the ring, and photons from these regions are exciting previously hidden gas outside the ring, illuminating mass lost from the progenitor before the explosion. The inner debris are now well resolved, and clearly aspherical. Overall, these observations provide crucial insight into the earliest stages of formation of a supernova remnant.

GO 11670: The Host Environments of Type Ia Supernovae in the SDSS Survey

SN 2007uy and 2008D in NGC 2770 Supernovae have long attracted the attention of both amateur and professional astronomers as a means of studying the violent eruption and death of massive stars and degenerates. However, in the last decade they have also acquired considerable importance as distance indicators, tracing the expansion of the universe to redshifts well beyond the reach of more conventional yardsticks, such as cepheids, and providing a key underpinning for the hypothesised existcen of dark energy. Understanding the supernovae themselves, and, in particular, their progenitors, is key to accurately interpreting their luminosities and distances. The present program aims to tackle that aspect of the problem by using ACS to obtain deep, high resolution images of galaxies that have harboured recent type Ia supernovae. The targets are all drawn from the Sloan Digital Sky Survey, which has uncovered more than than 500 type Ia supernovae,. The supernovae themselves are long gone from view, but the ACS data will be used to probe the stellar populations in the immediate vicinity of the explosion, and hence gain a better understanding of the likely progenitor.

GO 10523: The stellar halo of dwarf galaxies

HST image of the dwarf galaxy, GR 8 The subdwarf stars that populate the Galactic halo are generally recognised as fossil remnants of the first episode of substantial star formation within the (proto-)Milky Way galaxy. The structure and density distribution of our own halo has been inferred partly from deep starcounts, partly from globular cluster systems and partly from the kinematics of local subdwarfs; most analyses favour a near-spherical system with density r-3.5. Subsequent observation programs, both from the ground and using HST, have extended observations to a number of nearby galaxies, notably the Andromeda spiral, M31. Almost all of the attention, however, has gone towards relatively massive galaxies. The present program aims to extend coverage to lower masses, with observations of three dwarf irregular galaxies within a few Mpc of the Mily Way. ACS will be used to take images in the F475W (B) and F814W (I) filters on fields spaced at significant distances from the galaxies DDO 190, UGC 08505 and GR 8. The aim is to use the colour-magnitude diagrams to trace the halo population in those galaxies to distances approaching half the virial radius. The data will be used to probe the halo radial density structure, estimate metallicities from the colour of the red giant branch, and search for any potential correlations with the metallicity of the parent galaxy.

Past weeks:
page by Neill Reid, updated 23/10/2009