This week on HST


HST Programs: May 10, 2010 - May 16, 2010


Program Number Principal Investigator Program Title
11142 Lin Yan, California Institute of Technology Revealing the Physical Nature of Infrared Luminous Galaxies at 0.3
11537 James C. Green, University of Colorado at Boulder COS-GTO: NUV Spectra of Bright Kuiper Belt Objects
11557 Gabriela Canalizo, University of California - Riverside The Nature of low-ionization BAL QSOs
11568 Seth Redfield, Wesleyan University A SNAPSHOT Survey of the Local Interstellar Medium: New NUV Observations of Stars with Archived FUV Observations
11594 John M. O'Meara, Saint Michaels College A WFC3 Grism Survey for Lyman limit absorption at z=2
11595 John M. O'Meara, Saint Michaels College Turning out the Light: A WFC3 Program to Image z>2 Damped Lyman Alpha Systems
11597 S. Adam Stanford, University of California - Davis Spectroscopy of IR-Selected Galaxy Clusters at 1 < z < 1.5
11598 Jason Tumlinson, Space Telescope Science Institute How Galaxies Acquire their Gas: A Map of Multiphase Accretion and Feedback in Gaseous Galaxy Halos
11602 Sahar S. Allam, Fermi National Accelerator Laboratory (FNAL) High-resolution imaging of three new UV-bright lensed arcs
11605 Travis Stuart Barman, Lowell Observatory Obtaining the Missing Links in the Test of Very Low Mass Evolutionary Models with HST
11626 Philip Massey, Lowell Observatory Searching for the Upper Mass Limit in NGC 3603, the Nearest Giant H II Region
11643 Ann Zabludoff, University of Arizona A Timeline for Early-Type Galaxy Formation: Mapping the Evolution of Star Formation, Globular Clusters, Dust, and Black Holes
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
11650 William M. Grundy, Lowell Observatory Mutual Orbits, Colors, Masses, and Bulk Densities of 3 Cold Classical Transneptunian Binaries
11654 Robert P. Kirshner, Harvard University UV Studies of a Core Collapse Supernova
11657 Letizia Stanghellini, National Optical Astronomy Observatory, AURA The population of compact planetary nebulae in the Galactic Disk
11663 Mark Brodwin, Smithsonian Institution Astrophysical Observatory Formation and Evolution of Massive Galaxies in the Richest Environments at 1.5 < z < 2.0
11664 Thomas M. Brown, Space Telescope Science Institute The WFC3 Galactic Bulge Treasury Program: Populations, Formation History, and Planets
11666 Adam J. Burgasser, University of California - San Diego Chilly Pairs: A Search for the Latest-type Brown Dwarf Binaries and the Prototype Y Dwarf
11682 Micaela B. Stumpf, Max-Planck-Institut fur Astronomie, Heidelberg An HST/STIS spectroscopic investigation: is Kelu-1 AB a brown dwarf - brown dwarf binary?
11696 Matthew A. Malkan, University of California - Los Angeles Infrared Survey of Star Formation Across Cosmic Time
11697 Slawomir Stanislaw Piatek, New Jersey Institute of Technology Proper Motion Survey of Classical and SDSS Local Group Dwarf Galaxies
11699 Thomas Rauch, Universitat Tubingen, Institut fur Astronomie & Astrophysik On the evolutionary status of extremely hot helium stars - are the O{He} stars successors of the R CrB stars?
11700 Michele Trenti, University of Colorado at Boulder Bright Galaxies at z>7.5 with a WFC3 Pure Parallel Survey
11704 Brian Chaboyer, Dartmouth College The Ages of Globular Clusters and the Population II Distance Scale
11705 Frederick W. Hamann, University of Florida Physical Properties of Quasar Outflows: From BALs to mini-BALs
11712 John P. Blakeslee, Dominion Astrophysical Observatory Calibration of Surface Brightness Fluctuations for WFC3/IR
11713 Howard E. Bond, Space Telescope Science Institute The Light Echoes around V838 Monocerotis
11720 Patrick Dufour, Universite de Montreal Detailed analysis of carbon atmosphere white dwarfs
11728 Timothy M. Heckman, The Johns Hopkins University The Impact of Starbursts on the Gaseous Halos of Galaxies
11730 Nitya Jacob Kallivayalil, Massachusetts Institute of Technology Continued Proper Motions of the Magellanic Clouds: Orbits, Internal Kinematics, and Distance
11788 George Fritz Benedict, University of Texas at Austin The Architecture of Exoplanetary Systems
11789 George Fritz Benedict, University of Texas at Austin An Astrometric Calibration of Population II Distance Indicators
11837 Martin Elvis, Smithsonian Institution Astrophysical Observatory A Co-ordinated Chandra, Suzaku, HST Campaign for NGC3227
12021 Philip Kaaret, University of Iowa An Irradiated Disk in an Ultraluminous X-Ray Source
12051 Saul Perlmutter, University of California - Berkeley Cross Calibration of NICMOS and WFC3 in the Low-Count-Rate Regime

Selected highlights

GO 11644: A dynamical-compositional survey of the Kuiper belt: a new window into the formation of the outer solar system

The architecture of the outer Solar System The Kuiper Belt lies beyond the orbit of Neptune, extending from ~30 AU to ~50 AU from the Sun, and includes at least 70,000 objects with diameters exceeding 100 km. Setting aside Pluto, the first trans-Neptunian objects were discovered in the early 1990s. Most are relatively modest in size, with diameters of a few hundred km and photometric properties that suggested an icy composition, similar to Pluto and its main satellite, Charon. Over the last three years, a handful of substantially larger bodies have been discovered, with diameters of more than 1000 km; one of the objects, 2003 UB313, is comparable in size to Pluto (2320 km.). At the same time, ground-based surveys, such as the Deep Ecliptic Survey, the Canada-France Ecliptic plane Survey and the Palomar Quest Survey, scanned the ecliptic for fainter, lower-mass objects, with the aim of using their properties to assess the likely chemical composition and dynamical history of the early Solar System. The present program will use Wide Field Camera 3 to push up to 2 magnitudes fainter than these ground-based studies, providing reliable estimates of compositions for a representative sample of KBOs.

GO 11666: Chilly Pairs: A Search for the Latest-type Brown Dwarf Binaries and the Prototype Y Dwarf

NICMOS images of the ultracool L/T binary, 2MASS J22521073-1730134; the northern component, notably fainter at F160W, is the T dwarf. Ultracool dwarfs are defined as having spectral types later than M7, and therefore include the recently discovered L and T dwarfs. They encompass the lowest mass stars (masses < ~0.1 MSub) and sub-stellar mass brown dwarfs, with surface temperatures ranging from ~2500K (~M7) to <700K (late-type T dwarfs). Following their discovery over a decade ago, considerable theoretical attention has focused on the evolution of the intrinsic properties, particularly the details of the atmospheric changes in the evolution from type L to type T. This point marks the emergence of methane as a dominant absorber at near-infrared wavelengths. Current models suggest the transition occurs at ~1400-1200K, and that the spectral changes are at least correlated with, and perhaps driven by, the distribution and properties of dust layers ("clouds") within the atmosphere. The overall timescales associated with the process remain unclear. The present proposal aims to tackle this issue through identifying, and characterising, ultracool binary systems with extremely cool components. Since these systems are almost certainly coeval, the relative spectral energy distributions of the two components can be used to set constraints on evolutionary models. More than 80 ultracool binary systems are currently known; almost all have relatively small linear separations (<15 AU), and components with mass ratios close to one. The present program targets 27 ultracool dwarfs with spectral types in the range T5 to T9, and will use WFC3 IR observations to search for previously unrecognised close, faint companions.

GO 11696: Infrared Survey of Star Formation Across Cosmic Time

A region of massive star formation Star formation is the key astrophysical process in determining the overall evolution of galactic systems, the generation of heavy elements, and the overall enrichment of interstellar and intergalactic material. Tracing the overall evolution through a wide redshift range is crucial to understanding how gas and stars evolved to form the galaxies that we see around us now. The present program builds on the ability of HST to carry out parallel observations, using more than one instrument. While the Cosmic Origins Spectrograph is focused on obtaining ultraviolet spectra of unparalleled signal-to-noise, this program uses the near-infrared grisms mounted on the Wide-Field Camera 3 infrared channel to obtain low resolution spectra between 1 and 1.6 microns of randomly-selected nearby fields. The goal is to search for emission lines characteristic of star-forming regions. In particular, these observations are capable of detecting Lyman-alpha emission generated by star formation at redshfits z > 5.6. A total of up to 40 "deep" (4-5 orbit) and 20 "shallow" (2-3 orbit) fields will be targeted in the course of this observing campaign.

GO 11730: Continued Proper Motions of the Magellanic Clouds: Orbits, Internal Kinematics, and Distance

The Large Magellanic Cloud (upper left) with the Small Magellanic Cloud (right) and the (foreground) Galactic globular cluster47 Tucanae The Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC) are the most massive satellites of the Milky Way galaxy. The orbital motions of these systems can be used to probe the mass distribution of Milky Way, and backtracking the orbits can shed light on how the three systems have interacted, In particular, the well known Magellanic Stream, stretching between the two Clouds, is thought to be a product either of interactions between the Clouds, or of ram-stripping of gas from the LMC on its last passage through the Plane of the Milky Way. The present program builds on observations obtained at three previous epochs with the now-defunct ACS High Resolution Camera (ACS/HRC) and, in Cycle 16, with the Planetary camera on WFPC2. The previous programs targeted known QSOs lying behind the Clouds; the QSOs serve as fixed reference points for absolute astrometry of the numerous foreground LMC/SMC stars. First epoch observations were made in late 2002 (GO 9462), with the follow-up imaging in late 2004 (GO 10130) and 2007/2008 (GO 11201). The tangential motions of the Clouds amount to only a few milliarcseconds, but the high spatial resolution and high stability of HST imaging makes such measurements possible, even with only a 2-year baseline. Surprisingly, the initial results suggest that the 3-D motions of both clouds are much higher than expected, suggesting either that the LMC/SMC/MW is either dynamically very young, or unbound. The present program will use WFC3 to obtain fourth-epoch data in the same fields, providing a further crucial test of the initial results

Past weeks:
page by Neill Reid, updated 19/2/2010