This week on HST


HST Programs: July 7 - July 13, 2008


Program Number Principal Investigator Program Title Links
11103 Harald Ebeling, University of Hawaii A Snapshot Survey of The Most Massive Clusters of Galaxies Abstract
11107 Timothy M. Heckman, The Johns Hopkins University Imaging of Local Lyman Break Galaxy Analogs: New Clues to Galaxy Formation in the Early Universe Abstract
11129 Enrico V. Held, Osservatorio Astronomico di Padova The Star Formation History of the Fornax Dwarf Spheroidal Galaxy Abstract
11142 Lin Yan, California Institute of Technology Revealing the Physical Nature of Infrared Luminous Galaxies at 0.3 Abstract
11144 Richard Bouwens, University of California, Santa Cruz Building on the Significant NICMOS Investment in GOODS: A Bright, Wide-Area Search for z>=7 Galaxies Abstract
11151 Gregory J. Herczeg, California Institute of Technology Evaluating the Role of Photoevaporation of Protoplanetary Disk Dispersal Abstract
11155 Marshall D. Perrin, University of California - Berkeley Dust Grain Evolution in Herbig Ae Stars: NICMOS Coronagraphic Imaging and Polarimetry Abstract
11167 Sahar S. Allam, Fermi National Accelerator Laboratory Dust Grain Evolution in Herbig Ae Stars: NICMOS Coronagraphic Imaging and Polarimetry Abstract
11196 Aaron S. Evans, State University of New York at Stony Brook An Ultraviolet Survey of Luminous Infrared Galaxies in the Local Universe Abstract
11202 Leon Koopmans, Kapteyn Astronomical Institute The Structure of Early-type Galaxies: 0.1-100 Effective Radii Abstract
11206 Kai G. Noeske, University of California - Santa Cruz At the cradle of the Milky Way: Formation of the most massive field disk galaxies at z>1 Abstract
11210 George Fritz Benedict, University of Texas at Austin The Architecture of Exoplanetary Systems Abstract
11211 George Fritz Benedict, University of Texas at Austin An Astrometric Calibration of Population II Distance Indicators Abstract
11212 Douglas R. Gies, Georgia State University Research Foundation Filling the Period Gap for Massive Binaries Abstract
11213 Gerard T. van Belle, California Institute of Technology Distances to Eclipsing M Dwarf Binaries Abstract
11214 John Wisniewski, NASA Goddard Space Flight Center HST/FGS Astrometric Search for Young Planets Around Beta Pic and AU Mic Abstract
11215 Scott F. Anderson, University of Washington New Sightlines for the Study of Intergalactic Helium: Dozens of High-Confidence, UV-Bright Quasars from SDSS/GALEX Abstract
11222 Michael Eracleous, The Pennsylvania State University Direct Detection and Mapping of Star Forming Regions in Nearby, Luminous Quasars 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
11237 Lutz Wisotzki, Astrophysikalisches Institut Potsdam The origin of the break in the AGN luminosity function Abstract
11498 Amy Simon-Miller, NASA Goddard Space Flight Center 2008 Passage of Jupiter's Great Red Spot and Oval BA Abstract
11513 Nial Tanvir, University of Leicester The afterglow and host galaxy of GRB 080319: the first "naked eye" burst Abstract
11545 Ben Davies, Rochester Institute of Technology A NICMOS survey of newly-discovered young massive clusters Abstract
11547 Dimitrios Gouliermis, Max-Planck-Institut fur Astronomie, Heidelberg Characterizing Pre-Main Sequence Populations in Stellar Associations of the Large Magellanic Cloud Abstract

Some selected highlights

GO 11129: The Star Formation History of the Fornax Dwarf Spheroidal Galaxy

The Fornax dwarf galaxy The Milky Way has at least fifteen satellite galaxies. The most prominent are the Large and Small Magellanic Clouds, irregular galaxies which have been known since at least the tenth century. The remaining systems are all gas-poor dwarf spheroidal systems, with luminosities less than 109 L/sub>Sun and masses less than The Fornax dwarf is one of the larger systems. Originally discovered by Harlow Shapley, during his stint at Harvard's Boyden Observatory in 1938, Fornax lies at a distance of ~150 kpc. Ground-based observations have identified several globular clusters, and the colour-magnitude diagram indicates that this is a system made up predominantly of old stellar populations, although with a smattering of younger stars. The present program aims to refine the age estimate, by using WFPC2 to obtain deep imaging of several fields across the dwarf galaxy.

GO 11142: Revealing the Physical Nature of Infrared Luminous Galaxies at 0.3

NICMOS image of the nearby luminous IR galaxy, Arp 299 Luminous infrared galaxies (LIRGs) have total luminosities that exceed 1011.4 LSun, with most of the energy emitted at wavelengths longward of 10 microns. Many (perhaps most) of these galaxies are interacting or merging disk galaxies, with the excess infrared luminosity generated by warm dust associated with the extensive star formation regions. Many systems also exhibit an active nucleus, and may be in the process of evolving towards an S0 or elliptical merger remnant. The present program is targeting systems with redshifts in the range 0.3 < z < 2.7, combining imaging at near-infrared (NICMOS on HST) and mid-infrared (MIPS on Spitzer) wavelengths. All of the systems already have Spitzer mid-infrared spectra, allowing not only an accurate characterisation of the over all flux distribution, and a \ determination of the total luminosity, but also providing insight into the galaxian dust content and chemical evolution.

GO 11202 The Structure of Early-type Galaxies: 0.1-100 Effective Radii

HST16309+8230, a disk galaxy, distorted due to gravitational lensing by a foreground elliptical Despite their apparently simple appearance, the processes responsible for the formation and evolution of elliptical galaxies remain somewhat obscure. It is clear that most star formationin these systems must occur at early epochs, since these systems are highly gas poor at even moderate redshifts. Grabitational lensing provies one of the more important tools for investigating these systems, since it can probe the detailed form of the mass distribution, and test for the presence of sub-structure in the underlying dark matter, as predicted by some theoretical models. The present program is combining high-resolution, multi-colour HST imaging with ground-based low-resolution VLT/Keck spectroscopic observations of over 50 strong lensing systems. The resultant datasets can be used to investigate the structure of elliptical galaxies over a wide range of radii, and test the predictions of relevant theoretical models.

GO 11498: 2008 Passage of Jupiter's Great Red Spot and Oval BA

The Great Red Spot and the white ovaL (HST image) In the late 1930s, bright white clouds expanded and encircled Jupiter's southern hemisphere in a band near 33 degrees south planetographic latitude. Those clouds collapsed into three large anticyclonic storms, later named the White Ovals, that were second in size only to the Great Red Spot, GRS. In the mid to late 1990s these storms suddenly approached each other very closely, resulting in the 1998 merger of two of the storms (hence the designation Oval BA). In 2000, the third oval also merged, leaving one remaining large White Oval. Early in 2006, amateur observers noted that the oval appeared to be changing in appearance and turning red, leading to the feature redesignated as the Little Red Spot - LRS. While small red spots do appear on Jupiter from time to time, they usually form as a colored spot, cloud over, and become white, rather than the opposite. Hubble was used to image the atmospheric features throughout 2006 and 2007. Both the GRS and the LRS shows drifts in longitude, with the GRS drifting westward and the LRS eastward. The two systems pass each other every 2 years and, at that time, the relative wind motions can lead to changes in morphology. The present proposal aims to use WFPC2 to obtain multiwavelength observations during the 2008 passage, studying the vertical structure of the storm, and investigating possible mechanisms that underlie any observed changes in appearance.

Past weeks:
page by Neill Reid, updated 18/5/2008