This week on HST

HST Programs: July 11, 2010 - July 17, 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
11360 Robert W. O'Connell, The University of Virginia Star Formation in Nearby Galaxies
11527 James C. Green, University of Colorado at Boulder COS-GTO: An absorption study of galactic intermediate velocity clouds using hot stars in globular clusters
11556 Marc W. Buie, Southwest Research Institute Investigations of the Pluto System
11565 Sebastien Lepine, American Museum of Natural History A search for astrometric companions to very low-mass, Population II stars
11567 Charles R. Proffitt, Computer Sciences Corporation Boron Abundances in Rapidly Rotating Early-B Stars.
11576 Jean-Michel Desert, Harvard University Physical parameters of the upper atmosphere of the extrasolar planet HD209458b
11577 Brad C. Whitmore, Space Telescope Science Institute Opening New Windows on the Antennae with WFC3
11592 Nicolas Lehner, University of Notre Dame Testing the Origin{s} of the Highly Ionized High-Velocity Clouds: A Survey of Galactic Halo Stars at z>3 kpc
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
11598 Jason Tumlinson, Space Telescope Science Institute How Galaxies Acquire their Gas: A Map of Multiphase Accretion and Feedback in Gaseous Galaxy Halos
11599 Richard A. Wade, The Pennsylvania State University Distances of Planetary Nebulae from SNAPshots of Resolved Companions
11605 Travis Stuart Barman, Lowell Observatory Obtaining the Missing Links in the Test of Very Low Mass Evolutionary Models with HST
11613 Roelof S. de Jong, Astrophysikalisches Institut Potsdam GHOSTS: Stellar Outskirts of Massive Spiral Galaxies
11630 Kathy Rages, SETI Institute Monitoring Active Atmospheres on Uranus and Neptune
11631 Iain Neill Reid, Space Telescope Science Institute Binary brown dwarfs and the L/T transition
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
11658 David A. Turnshek, University of Pittsburgh Probing the Outer Regions of M31 with QSO Absorption Lines
11661 Misty C. Bentz, University of California - Irvine The Black Hole Mass - Bulge Luminosity Relationship for the Nearest Reverberation-Mapped AGNs
11663 Mark Brodwin, Smithsonian Institution Astrophysical Observatory Formation and Evolution of Massive Galaxies in the Richest Environments at 1.5 < z < 2.0
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
11687 Thomas R. Ayres, University of Colorado at Boulder SNAPing Coronal Iron
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?
11712 John P. Blakeslee, Dominion Astrophysical Observatory Calibration of Surface Brightness Fluctuations for WFC3/IR
11721 Richard S. Ellis, California Institute of Technology Verifying the Utility of Type Ia Supernovae as Cosmological Probes: Evolution and Dispersion in the Ultraviolet Spectra
11728 Timothy M. Heckman, The Johns Hopkins University The Impact of Starbursts on the Gaseous Halos of Galaxies
11838 Herman L. Marshall, Massachusetts Institute of Technology Completing a Flux-limited Survey for X-ray Emission from Radio Jets
12018 Andrea H. Prestwich, Smithsonian Institution Astrophysical Observatory Ultra-Luminous x-Ray Sources in the Most Metal-Poor Galaxies
12019 Christy A. Tremonti, University of Wisconsin - Madison After the Fall: Fading AGN in Post-starburst Galaxies
12057 Julianne Dalcanton, University of Washington A Panchromatic Hubble Andromeda Treasury - I

Selected highlights

GO 11556: Investigations of the Pluto System

Hubble Space Telescope image of Pluto, Charon and the two new moons, Nix & Hydra Pluto, one of the largest members of the Kuiper Belt and, until recently (still, for some), the outermost planet in the solar system, has been in the news over the last year or two. Besides the extended "planet"/"dwarf planet" debate, Pluto is the primary target of the New Horizons Mission, and Hubble observations in 2005 led to the discovery of two small moons. Together with Charon, itself only discovered in 1978, these additions make Pluto a 4-body system. Christened Nix and Hydra, the two new moons are 5,000 fainter than Pluto itself, implying diameters as small as ~30-50 km if the surface composition is similar to Pluto itself. The present program aims to better characterise these bodies through multicolour observations with WFC3. The observations are phased with a cadence that samples the different orbital periods: 6.4 days for Pluto/Charon; 24.9 days for Nix/Pluto; and 38 days for Hydra/Pluto. The goal is to identify systematic photometric variations that might probe the rotation period, testing whether these moons are in synchronous rotation with Pluto itself.

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 11599: Distances of Planetary Nebulae from SNAPshots of Resolved Companions

HST image of the Eskimo planetary nebula, NGC 2392 Planetary nebulae are the spectacular results of the penultiumate evoutionary phase of intermediate-mass stars. Towards the conclusion of the second, or asymptotic, giant branch, ~1 to ~7 solar mass stars have achieved radii exceeding 100 RSun and their extensive envelopes are subject to long-period, opacity-driven pulsations and substantial mass loss. AGB evolution terminates with the ejection of the stellar envelope, revealing the bare core, with an initial surface temperature approaching 100,000K. The core cools to become a white dwarf but, during the initial phase, its luminosity is sufficient to excite gases in the expanding envelope, producing a planetary nebula. These objects are extremely spectacular, but also, in Galactic terms, rare. As a result, we only know reliable distances to a handful of such systems. The present program aims to tackle this issue through observations of planetary nebulae with known or suspected lower-mass companions. Once confirmed as binaries, distances can be estimated using the companions, which still reside on the main sequence.

GO 11697: Proper Motion Survey of Classical and SDSS Local Group Dwarf Galaxies

The low-mass dwarf galaxy, Leo II The Milky Way, m31 and M33 are the three largest galaxies in the Local Group. The system, however, includes more than 25 other members, the majority being dwarf spheroidal galaxies that are satellites of either M31 or the Milky Way. Those galaxies have old, evolved stellar populations, and even the most prominent have masses that are less than a few x 107 MSun, or 10-4 that of the Milky Way. All of these galaxies are moving in the potential set by the overall Local Group system, but dominated by M31 and the Milky Way. Determining full space motions for the dwarfs therefore provide a means of constraining that potential. Even thought the galaxies, and their brightest stellar constituents, are faint, measuring radial velocity is a relatively straightforward procedure. Deriving tangential motions is not, since the typical proper motions of these systems are a few mas/year at best. The present proposal aims to capitalise on the exceptional resolution and high stability of HST to address this issue. WFC3 will target 7 dwarf galaxies, imaging fields that are centred on a background QSO. That QSO serves as a reference point for measurement of the transverse motion of stars in the foreground dwarf galaxy.

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