This week on HST

HST Programs: April 14 - April 20, 2008

Program Number Principal Investigator Program Title Links
11113 Keith S. Noll, Space Telescope Science Institute Binaries in the Kuiper Belt: Probes of Solar System Formation and Evolution Abstract
11117 David Kent Sing CNRS, Institut d'Astrophysique de Paris The Search for Atmospheric Water in the Transiting Planet HD189733b Abstract
11120 Daniel Wang, University of Massachusetts A Paschen-Alpha Study of Massive Stars and the ISM in the Galactic Center Abstract
11122 Bruce Balick, University of Washington Expanding PNe: Distances and Hydro Models Abstract
11125 Joel N. Bregman, University of Michigan The Dynamical Evolution of Globular Clusters Abstract
11130 Luis Ho, Carnegie Institution of Washington AGNs with Intermediate-mass Black Holes: Testing the Black Hole-Bulge Paradigm, Part II Abstract
11132 Markus R. Janson, Max-Planck-Institut fur Astronomie, Heidelberg Constraining the age of the AB Dor system Abstract
11142 Lin Yan, California Institute of Technology Revealing the Physical Nature of Infrared Luminous Galaxies at 0.3 Abstract
11143 Andrew J. Baker, Rutgers the State University of New Jersey NICMOS imaging of submillimeter galaxies with CO and PAH redshifts Abstract
11149 Eiichi Egami, University of Arizona Characterizing the Stellar Populations in Lyman-Alpha Emitters and Lyman Break Galaxies at 5.7 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
11210 George Fritz Benedict, University of Texas at Austin The Architecture of Exoplanetary Systems Abstract
11222 Michael Eracleous, The Pennsylvania State University Direct Detection and Mapping of Star Forming Regions in Nearby, Luminous Quasars Abstract
11230 Christopher P. O'Dea, Rochester Institute of Technology HST FUV Observations of Brightest Cluster Galaxies: The Role of Star Formation in Cooling Flows and BCG Evolution 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

Some selected highlights

GO 11117: The Search for Atmospheric Water in the Transiting Planet HD189733b

Key events in a planetary transit HD 198733 is a 7th magnitude G5 dwarf that lies at a distance of ~20 parsecs from the Sun, in the direction of the constellation of Vulpecula. Like many other nearby solar-type stars, HD 189733 has an associated planetary system, including a hot Jupiter, a ~1.15 MJ gas giant with an orbital period of 2.12 days. Most significantly, that inner planet transits the central star, making HD 189733 the closest transiting system found so far. Transiting systems offer a potential gold-mine for extrasolar planetary studies, since not only is the orbital inclination well defined, but the diameter (and hence the average density) is directly measureable form the eclipse depth, while the atmospheric composition can be probed through line absorption or re-radiated thermal flux. The results from these measurments can be used to test, and improve, theoretical models of extrasolar planets. These observations are best done from space (indeed, the only successful atmospheric observations to date have been with HST and Spitzer). Previous observations with HST have been used to determine accurate radii for HD 189733b (e.g. GO 10923 ); the present program aims to search for evidence of water absorption by differencing NICMOS narrowband images taken before, during and after primary transit.

GO 11120: A Paschen-Alpha Study of Massive Stars and the ISM in the Galactic Center

A multi-wavelength composite image of the Galactic Centre (red - 90 cm radio data; green, mid-IR data; blue, X-ray) The Galactic Centre lies in the heart of the constellation of Sagittarius, and at a distance of ~8 kiloparsecs from the Sun. Galactic nuclei are the likely end-point for mass accretion, and are generally the site of highly energetic activity; the Galactic Centre is no exception. AO near-infrared imaging has been brought to bear on this issue, resolving a number of stars within the core, close to the compact radio source Sagittarius A*. Monitoring of those sources over the last decade has shown that they are in rapid orbital motion around a very massive central object, now clearly identified as a ~3 million solar-mass black hole. Moving beyond the core, to distances of tens of parsecs from centre, observations have revealed molecular gas and young star forming regions. The aim of the present proposal is to use the NICMOS NIC3 camera to survey a ~32 x 13 arcminute region (~75 pc x 30 pc) in two narrowband filters: F187N, ceentred on the Paschen alpha line; and F190N, providing the continuum flux. These obbservations will provide a detailed map of the star forming activity within the Galactic nucleus.

GO 11149: Characterizing the Stellar Populations in Lyman-Alpha Emitters and Lyman Break Galaxies at 5.7<7 in the Subaru Deep Field

Optical imagiung of the Subaru deep field The Subaru Deep Field (SDF) lies at 13h24m38.9s+27d29'25", near the North Galactic Pole and more than 30 arcminutes from the nearest bright star or galaxy. The field has been imaged to faint magnitudes (V>27.5, JH>26.0) at both optical and near-infrared wavelengths using, respectively, Suprime-Cam and CIRCO mounted on the Subaru 8.2-metre telescope, located on the summit of Mauna Kea, Hawaii. The goal is to use these data to probe the high redshift universe, searching for "drop-outs" with colours consistent with redshifts z > 6 - sources where the Lyman limit is redshifted longward of 7000 Angstroms, leading to no flux in the optical r-band and extremely red (r-i) colours. High redshift systems are expected to be relatively rare, so these ground-based observations offer an advantage over HST in terms of areal coverage (Suprime-Cam covers 30'x37'); however, the higher angular resolution and increased sensitivity of HST offer significant advantages in characterising candidate galaxies. The present proposal is using NICMOS on HST to obtain follow-up F110W/F160W (J/H) images of 20 spectroscopically confirmed 5.7 < z < 7 Ly-alpha emitters or lyman-break galaxies in the SDF. In addition, the IRAC camera on Spitzer is being used to obtain mid-IR data for the same galaxies. The observations will be used to fully characterise the spectral energy distributions and morphologies of these sources.

Past weeks:
page by Neill Reid, updated 9/4/2008