This week on HST

HST Programs: June 14, 2010 - June 20, 2010

table border="1" cellpadding="5" cellspacing="0"> Program Number Principal Investigator Program Title 11538 James C. Green, University of Colorado at Boulder COS-GTO: Imaging of Mid-UV Emissions from Io in Eclipse 11555 Alexander Brown, University of Colorado at Boulder Transition Region and Chromospheric Activity on Low Metallicity Arcturus Moving Group `Alien' Dwarfs 11565 Sebastien Lepine, American Museum of Natural History A search for astrometric companions to very low-mass, Population II stars 11568 Seth Redfield, Wesleyan University A SNAPSHOT Survey of the Local Interstellar Medium: New NUV Observations of Stars with Archived FUV Observations 11577 Brad C. Whitmore, Space Telescope Science Institute Opening New Windows on the Antennae with WFC3 11588 Raphael Gavazzi, CNRS, Institut d'Astrophysique de Paris Galaxy-Scale Strong Lenses from the CFHTLS survey 11591 Jean-Paul Kneib, Laboratoire d'Astrophysique de Marseille Are Low-Luminosity Galaxies Responsible for Cosmic Reionization? 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 11593 Michael C. Liu, University of Hawaii Dynamical Masses of the Coolest Brown Dwarfs 11598 Jason Tumlinson, Space Telescope Science Institute How Galaxies Acquire their Gas: A Map of Multiphase Accretion and Feedback in Gaseous Galaxy Halos 11609 Julio Chaname, Carnegie Institution of Washington NGC 6266: The Smoking Gun of Intermediate-Mass Black Holes in Galactic Globular Clusters? 11630 Kathy Rages, SETI Institute Monitoring Active Atmospheres on Uranus and Neptune 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 11655 Konrad Kuijken, Universiteit Leiden Dynamics of the Galactic bulge/bar 11657 Letizia Stanghellini, National Optical Astronomy Observatory, AURA The population of compact planetary nebulae in the Galactic Disk 11670 Peter Garnavich, University of Notre Dame The Host Environments of Type Ia Supernovae in the SDSS Survey 11677 Harvey B. Richer, University of British Columbia Is 47 Tuc Young? Measuring its White Dwarf Cooling Age and Completing a Hubble Legacy 11686 Nahum Arav, Virginia Polytechnic Institute and State University The Cosmological Impact of AGN Outflows: Measuring Absolute Abundances and Kinetic Luminosities 11687 Thomas R. Ayres, University of Colorado at Boulder SNAPing Coronal Iron 11694 David R. Law, University of California - Los Angeles Mapping the Interaction between High-Redshift Galaxies and the Intergalactic Environment 11696 Matthew A. Malkan, University of California - Los Angeles Infrared Survey of Star Formation Across Cosmic Time 11698 Mary E. Putman, Columbia University in the City of New York The Structure and Dynamics of Virgo's Multi-Phase Intracluster Medium 11700 Michele Trenti, University of Colorado at Boulder Bright Galaxies at z>7.5 with a WFC3 Pure Parallel Survey 11702 Hao-Jing Yan, The Ohio State University Research Foundation Search for Very High-z Galaxies with WFC3 Pure Parallel 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 11707 Kailash Sahu, Space Telescope Science Institute Detecting Isolated Black Holes through Astrometric Microlensing 11708 Morten Andersen, European Space Agency - ESTEC Determining the Sub-stellar IMF in the Most Massive Young Milky Way Cluster, Westerlund 1 11714 Howard E. Bond, Space Telescope Science Institute Snapshot Survey for Planetary Nebulae in Local Group Globular Clusters 11719 Julianne Dalcanton, University of Washington A Calibration Database for Stellar Models of Asymptotic Giant Branch Stars 11720 Patrick Dufour, Universite de Montreal Detailed analysis of carbon atmosphere white dwarfs 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 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 11731 C. S. Kochanek, The Ohio State University Research Foundation Studying Cepheid Systematics in M81: H-band Observations 11732 C. S. Kochanek, The Ohio State University Research Foundation The Temperature Profiles of Quasar Accretion Disks 11741 Todd M. 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 11742 Gabor Worseck, University of California - Santa Cruz Probing HeII Reionization with GALEX-selected Quasar Sightlines and HST/COS 11818 Paul Kalas, University of California - Berkeley NICMOS confirmation of an extrasolar planet candidate directly detected with ACS 11835 Mark Birkinshaw, University of Bristol The multi-faceted X-ray activity of low-redshift active galaxies 12016 Carol A. Grady, Eureka Scientific Inc. The Stars and Edge-on Disks of PDS 144: An Intermediate-Mass Analog of Wide T Tauri Multiple Stars

Selected highlights

GO 11577: Opening New Windows on the Antennae with WFC3

HST ACS image of NGC 4038/4039, the Antennae Galaxy merging has been recognised in recent years as a major process that influences galaxy evolution. One of the key systems that has contributed to that understanding is the Antennae galaxy, also known as NGC 4038/4039 or Arp 244. Originally identified by William Herschel in the course of his star sweeps, the Antennae is a nearby pair of galaxies (a spiral and a barred spiral) undergoing a major merger that started approximately 1 billion years ago. The interactions have led to etensive gravitational distortions, including two prominent tidal tails, and extensive star formation. HST observations over the last 15 years have revealed more and more details of the star formation\ triggered by the merger, with first WFPC2, then NICMOS and ACS imaging of key regions. The present program aims to build on those previous investigations by using ultraviolet imaging with WFC3 to probe young star clusters within the colliding disks.

GO 11588: Galaxy-Scale Strong Lenses from the CFHTLS survey

ACS images of galaxy-galaxy Einstein ring lenses Gravitational lensing is a consequence the theory of general relativity. Its importance as an astrophysical tool first became apparent with the realisation (in 1979) that the quasar pair Q0957+561 actually comprised two lensed images of the same background quasar. In the succeeding years, lensing has been used primarily to probe the mass distribution of galaxy clusters, using theoretical models to analyse the arcs and arclets that are produced by strong lensing of background galaxies, and the large-scale mass distribution, through analysis of weak lensing effects on galaxy morphologies. Gravitational lensing can also be used to investigate the mass distribution of individual galaxies. Until recently, the most common background sources were quasars. Galaxy-galaxy lenses, however, offer a distinct advantage, since the background source is extended, and therefore imposes a stronger constraints on the mass distribution of the lensing galaxy than a point-source QSO. The CFHT Legacy survey was a concerted effort by Canada and France to use almost half of their dark/grey time on the Canada-France-Hawaii telescope to obtain deep images with the MegaCam 1x1 degree imager. In ttoal, about 450 nights were devoted to this project between mid-2003 and early 2009, covering almost 600 square degrees to varying depths. The resultant survey provides a powerful means for identifying candidate galaxy-galaxy lenses. This program is using WFC3 SNAP imaging to verify the nature of those candidates, and provide the angular resolution necessary to model the mass distribution.

GO 11630 Monitoring active Atmospheres on Uranus and Neptune

Nicmos image of aurorae on Uranus The atmospheres of the gas giant planets in the solar system are dynamic entities that can exhibit dramatic changes over a variety of timescales. Those changes are most apparent in Jovian atmosphere, which displays a wide variety of bands and spots, reflecting complex meteorological phenomena (see, e.g., previous ACS observations of the upper atmosphere and of the new little red spot ). This is not surprising since Jupiter atmosphere receives the highest input of solar energy. However, secular variations are also evident in the atmospheres of the outer planets, albeit usually at a more subtle level. The present program builds on past HST programs (see Program GO 10534 ) that have monitored atmospheric changes in the two outermost gas giants, Uranus and Neptune. Both exhibit long-term seasonal variations, whose origins are not yet well understood; both are capable of generating dark spots - phenomena that are presumably related to Jupiter's Great Red Spot and Saturn's Great White Spot. The present observations use a variety of filters on Wide-Field Camera 3 (notably the quad methane filter) to probe conditions are a variety of levels within the planetary atmospheres.

GO 11698: The Structure and Dynamics of Virgo's Multi-Phase Intracluster Medium

The central regions of the Virgo cluster Galaxy clusters are building blocks for the largest structures in the universe. Star formation ensures that galaxies are the most prominent constituents of the cluster structure, but the bulk of the baryonic material (perhaps as much as 90%) resides in hot gas that permeates the potential well defined by the underlying dark matter. The low density (10-3 particles cm-3) gas is extremely hot (temperatures of 107 to 108 Kelvin), and therefore directly detectable at X-ray wavelengths. Those observations provide a means of mapping the gas density distribution, but they are not able to determine the dynamical properties of the intracluster medium (ICM). The most effective means of probing the dynamics is through spectroscopic observations of background sources, where the line-of-sight absorption features introduced by the ICM gas allow one to identify velocity structure. The present program aims to use 15 background QSOs, identified by SDSS, as a first step in tracing the dynamics within the Virgo cluster ICM.

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