This week on HST

HST Programs: February 7, 2011 - February 13, 2011

Program Number Principal Investigator Program Title
11591 Jean-Paul Kneib, Laboratoire d'Astrophysique de Marseille Are Low-Luminosity Galaxies Responsible for Cosmic Reionization?
11611 D. Michael Crenshaw, Georgia State University Research Foundation Are Narrow-Line Seyfert 1 Galaxies Viewed Pole-on?
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
11695 Kevin Luhman, The Pennsylvania State University Searching for the Bottom of the Initial Mass Function
11696 Matthew A. Malkan, University of California - Los Angeles Infrared Survey of Star Formation Across Cosmic Time
11725 Edward F. Guinan, Villanova University Eclipsing Binaries in the Local Group: III - Unprecedented Accuracy in Distance Determination to M33 and Calibration of the Cosmic Distance Scale
11830 Rita M. Sambruna, NASA Goddard Space Flight Center Jets at Intermediate Redshifts: Shedding Light on Emission Mechanisms and Physics
12065 Marc Postman, Space Telescope Science Institute Through a Lens, Darkly - New Constraints on the Fundamental Components of the Cosmos
12068 Marc Postman, Space Telescope Science Institute Through a Lens, Darkly - New Constraints on the Fundamental Components of the Cosmos
12070 Julianne Dalcanton, University of Washington A Panchromatic Hubble Andromeda Treasury - I
12161 David R. Ardila, Jet Propulsion Laboratory Accretion in Close Pre-Main-Sequence Binaries
12169 Boris T. Gaensicke, The University of Warwick The frequency and chemical composition of planetary debris discs around young white dwarfs
12182 Tuan Do, University of California - Los Angeles Measuring the physical properties of the Milky Way nuclear star cluster with proper motions
12184 Xiaohui Fan, University of Arizona A SNAP Survey for Gravitational Lenses Among z~6 Quasars
12191 James T. Lauroesch, University of Louisville Research Foundation, Inc. Prospecting for Rare Elements in the Interstellar Medium
12201 Brian Siana, California Institute of Technology Ionizing Emission from the Faint Galaxies Responsible for Reionization
12210 Adam S. Bolton, University of Utah SLACS for the Masses: Extending Strong Lensing to Lower Masses and Smaller Radii
12213 Roelof S. de Jong, Astrophysikalisches Institut Potsdam The Stellar Halo Profiles of Massive Disk Galaxies
12215 Nancy R. Evans, Smithsonian Institution Astrophysical Observatory Searching for the Missing Low-Mass Companions of Massive Stars
12234 Wesley Fraser, California Institute of Technology Differentiation in the Kuiper belt: a search for silicates on icy bodies.
12238 William E. Harris, McMaster University Supermassive Star Clusters in Supergiant Galaxies: Tracing the Enrichment of the Earliest Stellar Systems
12241 Robert P. Kirshner, Harvard University SAINTS - The SN 1987A Intensive Study
12275 Bart P. Wakker, University of Wisconsin - Madison Measuring gas flow rates in the Milky Way
12278 Thomas R. Ayres, University of Colorado at Boulder Advanced Spectral Library Project: Cool Stars
12286 Hao-Jing Yan, The Ohio State University Hubble Infrared Pure Parallel Imaging Extragalactic Survey {HIPPIES}
12289 J. Christopher Howk, University of Notre Dame A COS Snapshot Survey for z < 1.25 Lyman Limit Systems
12296 Howard E. Bond, Space Telescope Science Institute HST Observations of Astrophysically Important Visual Binaries
12299 Michael Eracleous, The Pennsylvania State University Spectroscopic Signatures of Binary and Recoiling Black Holes
12307 Andrew J. Levan, The University of Warwick A public SNAPSHOT survey of gamma-ray burst host galaxies
12321 Christopher Johns-Krull, Rice University The Parallax of the Planet Host Star XO-3
12326 Keith S. Noll, Space Telescope Science Institute Hubble Heritage 2.0
12374 Thomas R. Ayres, University of Colorado at Boulder Alpha Cen to the Max
12437 Alex V. Filippenko, University of California - Berkeley An Unusual Outburst from the Nucleus of the Quiescent Galaxy NGC 1589

Selected highlights

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

The view from Sedna: an artist's impression 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 11695: Searching for the Bottom of the Initial Mass Function

Multi-colour image of the Chamaeleon I region Chamaeleon I is a star-forming region that lies within a molecular cloud complex at a distance of ~150 parsecs from the Sun. The young cluster has been the subject of extensive ground-based observations, which have succeeded in identifying over 200 members, spread over an area of ~0.5 square degrees, with masses ranging from 2-3 solar masses to below the hydrogen burning limit. In addition, a subset of the cluster was targeted for deep HST observations with ACS and NICMOS in Cycle 13, while WFPC2 was used recently to search for evidence for disks and jets among the lower-mass memebrs. The cluster is much less massive than the Orion Nebula Cluster (ONC), and appears to break into two sub-units. Matched against theoretical isochrones, the colour-magnitude data suggest that the cluster has an age comparable to the ONC, with estimates of 3-4 Myrs for the southern sub-unit and 5-6 Myrs for the northern. The deep Cycle 13 observations were used to probe the form of the stellar mass function at the lowest masses, and found no evidence for a cut-off at low masses. The present observations build on the Cycle 13 program by providing second-epoch data that will allow separation of cluster and field to apparent magnitudes that correspond to masses as low as 3 MJupiter for cluster members.

GO 12070: A Panchromatic Hubble Andromeda Treasury

M31: the Andromeda spiral galaxy M31, the Andromeda galaxy, is the nearest large spiral system to the Milky Way (d ~ 700 kpc), and, with the Milky Way, dominates the Local Group. The two galaxies are relatively similar, with M31 likely the larger system; thus, Andromeda provides the best opportunity for a comparative assessment of the structural properties of the Milky Way. Moreover, while M31 is (obviously) more distant, our external vantage point can provide crucial global information that complements the detailed data that we can acquire on individual members of the stellar populations of the Milky Way. With the advent on the ACS and, within the last 2 years, WFC3 on HST, it has become possible to resolve main sequence late-F and G dwarfs, permitting observations that extend to sub-solar masses in M31's halo and disk. Initially, most attention focused on the extended halo of M31 (eg the Cycle 15 program GO 10816 ), with deep imaging within a limited number of fields revealing the complex metallicity structure within that population. With the initiation of the present Multi-Cycle Treasury program, attention switches to the M31 disk. "PHAT" will conduct a multi-waveband survey of approximately one third of disk and bulge, focusing on the north-east quadrant. Observations will extend over the next three cycles, and will provide a thorough census of upper main-sequence stars and star forming regions, matching the stellar distribution against the dust and gas distribution.
GO 12286: Hubble Infrared Pure Parallel Imaging Extragalactic Survey, HIPPIES

The ACS optical/far-red image of the Hubble Ultra Deep Field Galaxy evolution in the early Universe is a discipline of astronomy that has been transformed by observations with the Hubble Space Telescope. The original Hubble Deep Field, the product of 10 days observation in December 1995 of a single pointing of Wide Field Planetary Camera 2, demonstrated conclusively that galaxy formation was a far from passive process. The images revealed numerous blue disturbed and irregular systems, characteristic of star formation in galaxy collisions and mergers. Building on this initial progam, the Hubble Deep Field South (HDFS) provided matching data for a second southern field, allowing a first assessment of likely effects due to field to field cosmic variance, and the Hubble Ultra-Deep Field (UDF) probed to even fainter magitude with the Advanced Camera for Surveys (ACS). The highest redshift objects found in the UDF have redshifts approaching z~7. Pushing to larger distances, and greater ages, demands observatons at near-infrared wavelengths, as the characteristics signatures of star formation are driven further redward in the spectrum. Wide Field Camera 3, installed in Servicing Mission 4, is well suited to these observations, and a number of programs are in place in Cycle 17 that address these issues. Indeed, WFC3 is employed in pure parallel mode by several programs. These take advantage of other science programs, usually with COS, that involve 2-5 orbit pointings on sources at high galactic latitude. The WFC3 pointing is unplanned, since it depends on the orientation adopted for the prime observations, but 2-5 orbits of IR imaging can reach galaxies at redshifts exceeding z=7 (potentially even z~8) in high latitude fields. This is one of two such programs in the cycle 17 portfolio.

Past weeks:
page by Neill Reid, updated 2/5/2011