This week on HST


HST Programs: July 21 - July 27, 2008


Program Number Principal Investigator Program Title Links
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
11113 Keith S. Noll, Space Telescope Science Institute Binaries in the Kuiper Belt: Probes of Solar System Formation and Evolution Abstract
11130 Luis Ho, Carnegie Institution of Washington AGNs with Intermediate-mass Black Holes: Testing the Black Hole-Bulge Paradigm, Part II Abstract
11131 Walter Jaffe, Sterrewacht Leiden Star formation at large radii in cooling flow brightest cluster galaxies 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
11156 Kathy Rages, SETI Institute Monitoring Active Atmospheres on Uranus and Neptune Abstract
11157 Joseph H. Rhee, University of California - Los Angeles NICMOS Imaging Survey of Dusty Debris Around Nearby Stars Across the Stellar Mass Spectrum Abstract
11173 Arlin Crotts, Columbia University in the City of New York Completing an Accurate Map of M31 Microlensing Abstract
11175 Sandra M. Faber, University of California - Santa Cruz UV Imaging to Determine the Location of Residual Star Formation in Galaxies Recently Arrived on the Red Sequence Abstract
11178 William M. Grundy, Lowell Observatory Probing Solar System History with Orbits, Masses, and Colors of Transneptunian Binaries 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
11212 Douglas R. Gies, Georgia State University Research Foundation Filling the Period Gap for Massive Binaries Abstract
11218 Howard E. Bond, Space Telescope Science Institute Snapshot Survey for Planetary Nebulae in Globular Clusters of the Local Group 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
11544 Adam L. Kraus, California Institute of Technology The Dynamical Legacy of Star Formation Abstract
11545 Ben Davies, Rochester Institute of Technology A NICMOS survey of newly-discovered young massive clusters Abstract
11546 Michael Shara, American Museum of Natural History Ultra-Luminous Red Novae or Mergebursts? A Definitive HST Test 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 11144: Building on the Significant NICMOS Investment in GOODS: A Bright, Wide-Area Search for z>=7 Galaxies

Part of the GOODS/Chandra Deep Field South field, as imaged by HST The Great Observatory Origins Deep Survey (GOODS) is a multi-wavelength survey that covers two 150 sq. arcmin. fields, centred on the northern Hubble Deep Field (HDF) in Ursa Major and the Chandra Deep Field-South in Fornax. In addition to deep HST data at optical and near-infrared wavelengths, the fields have been covered at X-ray wavelengths by Chandra (obviously) and XMM-Newton; at mid-infrared wavelengths with Spitzer; and ground-based imaging and spectroscopy using numerous telescopes, including the Kecks, Surbaru and the ESO VLT. The prime aim of the GOODS program is to reconstruct the history of galaxy formation, star formation and nuclear galactic activity from the epoch of reionisation to the present. The present HST program builds on past results and aims to push observations to the highest redshifts, searching for galaxies at z > 7. Previously obtained GOODS data have been used to identify z-H dropouts - objects visible on F160W NICMOS images, but not on F098 ACS images. deeper NICMOS images of those candidates will be obtained in the J-band (F110W filter) to confirm whether the fluxes are consistent with 7 < z < 8 star-forming galaxies.

GO 11156: Monitoring Active Atmospheres on Uranus and Neptune

Voyager 2 image of Neptune Uranus and Neptune are the two "ice giants" of the Solar System, lying at average distances of 19 and 30 AU from the Sun. At those distances, their atmospheres are subject to much lower solar irradiance than Jupiter or Saturn and, as a result, they tend to show fewer large-scale disturbances. Even so, Neptune showed modest activity in the southern hemisphere between 2000 and 2003, although the disturbances have been less prominent in recent years. Uranus is unique among the major bodies in that it rotates on its side. With a polar obliquity is 98o degrees, its equator is close to perpendicular to the ecliptic plane. Consequently, as it circles the Sun, each pole spends almost half of a Uranian "year" (or 42 terrestrial years) hidden from the Sun in total darkness.On December 7th of this year, Uranus will pass through its equinox, with Sun passing overhead at the Uranian equator. This configuration will provide the first opportunity in modern times for us to view the entire northern hemisphere of the planet, and our first chance to view how the planetary atmosphere reacts to the change from night to day.
The present SNAPSHOT program is using WFPC2 to monitor the appearance of these two planets, acquiring narrowband optical images that both record the overall structure and probe the atmosphere at different depths.

GO 11175: UV Imaging to Determine the Location of Residual Star Formation in Galaxies Recently Arrived on the Red Sequence

Galaxy mergers and the red sequence

The overwhelming majority of galaxies are found in clusters. Observations show that almost all well-defined cluster systems at low and moderate redshift have a significant population of elliptical galaxies which have red colours, indicative of old stellar populations and minimal current star formation. The elliptical galaxies outline a distinct sequence in the colour-magnitude (or colour-mass) diagram, the so-called red sequence. Over the last few years, there has been considerable interest in understanding the origins of this sequence: how did the ellipticals form (most theories envisage mergers of gas-rich systems at moderate redshifts)? when did star formation cease in these galaxies (most galaxies in clusters at redshifts 1.5 < z < 3 seem to have active star formation)? are there environmentally-dependent effects? This proposal aims to address some of these questions through WFPC2 BVI and ACS/SBC observations of a number of low-redshift (0.04 < z < 0.10) galaxies that appear to have only recently arrived on the red sequence. The WFPC2 data will provide detailed morphologies, while the SBC ultraviolet imaging will be ued to search for traces of residual star formation.

GO 11544: The Dynamical Legacy of Star Formation

The central regions of the young star cluster, IC 348 General indications are that the overwhleming majority of stars in the Galactic disk form within clusters. Understanding the cluster environment is therefore important to understanding how most stars - and any associated planetary systems - form and evolve. Star-star interactions can lead to truncation of nascent disks, disruption of binary systems and even ejection from the cluster. The present program aims to investigate these issues by surveying the young star cluster, IC 348, with WFPC2, and combining the present set of observations with data from past cycles. Accurate relative astrometry will enable measurement of the relative stellar motions, and hence the cluster velocity dispersion, as well as premitting the identification of any stars with unusually high motions. In addition, these new WFPC2 images will push observations to fainter limits, potentially revealing new substellar-mass cluster members.

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