This week on HST

HST Programs: March 8, 2010 - March 14, 2010

Program Number Principal Investigator Program Title Links
11142 Lin Yan, California Institute of Technology Revealing the Physical Nature of Infrared Luminous Galaxies at 0.3 Abstract
11148 John Henry Debes, Goddard Spaceflight Center High Contrast Imaging of Dusty White Dwarfs Abstract
11149 Eiichi Egami, University of Arizona Characterizing the Stellar Populations in Lyman-Alpha Emitters and Lyman Break Galaxies at 5.7 Abstract
11202 Leon Koopmans, Kapteyn Astronomical Institute The Structure of Early-type Galaxies: 0.1-100 Effective Radii Abstract
11516 James Green, University of Colorado at Boulder COS-GTO: Cold ISM Abstract
11548 S. Thomas Megeath, University of Toledo NICMOS Imaging of Protostars in the Orion A Cloud: The Role of Environment in Star Formation Abstract
11555 Alexander Brown, University of Colorado at Boulder Transition Region and Chromospheric Activity on Low Metallicity Arcturus Moving Group `Alien' Dwarfs Abstract
11558 Orsola De Marco, American Museum of Natural History Planetary Nebulae, Globular Clusters and Binary Mergers Abstract
11570 Adam Riess, The Johns Hopkins University & Space Telescope Science Institute Narrowing in on the Hubble Constant and Dark Energy Abstract
11587 Xiaohui Fan, University of Arizona Probing Population III Star Formation in a z=7 Galaxy Abstract
11602 Sahar S. Allam, Fermi National Accelerator Laboratory High-resolution imaging of three new UV-bright lensed arcs Abstract
11603 Jennifer Andrews, Louisiana State University and A & M College A Comprehensive Study of Dust Formation in Type II Supernovae with HST, Spitzer and Gemini Abstract
11628 Eva Noyola, Max-Planck-Institut fur extraterrestrische Physik Globular Cluster Candidates for Hosting a Central Black Hole Abstract
11633 R. Michael Rich, University of California - Los Angeles A Precision White Dwarf Cooling Age for NGC 6397 Abstract
11639 Paula Szkody, University of Washington Catching Accreting WDs Moving into Their Instability Strip(s Abstract
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 Abstract
11657 Letizia Stanghellini, National Optical Astronomy Observatories The population of compact planetary nebulae in the Galactic Disk Abstract
11659 P. Frank Winkler, Middlebury College Probing the Interior of SN1006 Abstract
11664 Thomas M. Brown, Space Telescope Science Institute The WFC3 Galactic Bulge Treasury Program: Populations, Formation History, and Planets Abstract
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 Abstract
11737 David M. Meyer, Northwestern University The Distance Dependence of the Interstellar N/O Abundance Ratio: A Gould Belt Influence? Abstract
11828 Alexander Brown, University of Colorado at Boulder X-ray and FUV Photo-Ionization/-Excitation of Transitional Disks Around thePMS Stars HD135344B and Lk Halpha 330 Abstract
11838 Herman L. Marshall, Massachusetts Institute of Technology Completing a Flux-limited Survey for X-ray Emission from Radio Jets Abstract

Selected highlights

GO 11628: Globular Cluster Candidates for Hosting a Central Black Hole

Artist's impression of the visual distortions introduced by a black hole in a globular cluster The formation, and subsequent evolution, of intermediate-mass black holes (IMBHs) is a process of considerable importance for understanding th development of active galactic nuclei at high redshifts. IMBHs are generally expected to originate in globular-cluster-mass structures; hence, one might expect such objects to be present in some present-day Galactic clusters, particularly those that have undergone dynamical core collapse. The present program aims to obtain detailed measurements of the central radial profiles of a number of globulars, searching for systems with weak cusps that might indicate the presence of central IMBH. The targets are globulars with high central concentrations, including NGC 5946, NGC 6256, NGC 6342 and NGC 6355

GO 11644: A dynamical-compositional survey of the Kuiper belt: a new window into the formation of the outer solar system

The architecture of the outer Solar System The Kuiper Belt lies beyond the orbit of Neptune, extending from ~30 AU to ~50 AU from the Sun, and includes at least 70,000 objects with diameters exceeding 100 km. Setting aside Pluto, the first trans-Neptunian objects were discovered in the early 1990s. Most are relatively modest in size, with diameters of a few hundred km and photometric properties that suggested an icy composition, similar to Pluto and its main satellite, Charon. Over the last three years, a handful of substantially larger bodies have been discovered, with diameters of more than 1000 km; one of the objects, 2003 UB313, is comparable in size to Pluto (2320 km.). At the same time, ground-based surveys, such as the Deep Ecliptic Survey, the Canada-France Ecliptic plane Survey and the Palomar Quest Survey, scanned the ecliptic for fainter, lower-mass objects, with the aim of using their properties to assess the likely chemical composition and dynamical history of the early Solar System. The present program will use Wide Field Camera 3 to push up to 2 magnitudes fainter than these ground-based studies, providing reliable estimates of compositions for a representative sample of KBOs.

GO 11659: Probing the Interior of SN1006

Chandra X-ray image of the SN1006 supernova remnant In May 1006, Chinese, Arabic and European astronomers and stargazers independently identified a "guest star" in the region of the sky that would become known as the constellation Lupus. The star exceeded Venus in brightness at its peak, even threatening to rival the Moon, and remained visible until at least the end of that year. Indeed, there are suggestions that there a secondary brightening that preserved the star at naked eye magnitude until early 1008. The associated remnant was not identified until 1965, when Milne and Gardner resolved the radio source PKS 1459-41 into a circular shell, approximately 30 arcminutes in diameter. That remnant has since been studied extensively, notably by the Chandra satellite. HST is clearly poorly suited to mapping the remnant. However, there are a number of bright UV sources that lie behind the remnant, and those can be use to probe the remnant. This proposal will use COS to obtain spectra of these three sources, and trace the chemical and physical properties of the gas based on the absorption line profiles.

GO 11721: Verifying the Utility of Type Ia Supernovae as Cosmological Probes: Evolution and Dispersion in the Ultraviolet Spectra

A recent supernova in M100 Supernovae are the most spectacular form of stellar obituary. In recent years, these celestial explosions have acquired even more significance through the use of Type Ia supernovae as distance indicators in mapping the `dark energy' acceleration term of cosmic expansion. However, while there is a well-established model for the two main types of supernovae, runaway fusion on the surface of a white dwarf in a binary system, there are still some uncertainties as to the uniformity of the events, and the consequence potential for systematic uncertainties in the distance estimates. One of the questionmarks comes from spectroscopy of a number of supernovae at intermediate redshift (z~0.5) that appears to show a substantial dispersion in properties at UV wavelengths. The present program aims to probe this issue by using STIS to obtain UV spectra of nearby supernovae, and therefore examining the detailed behaviour in the local universe.

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