| Program Number | Principal Investigator | Program Title | Links |
| 10103 | George Benedict, University of Texas at Austin | FGS Astrometry of a Star Hosting an Extrasolar Planet: The Mass of Upsilon Andromedae d | Abstract |
| 10258 | Claudia Kretchmer, The Johns Hopkins University | Tracing the Emergence of the Hubble Sequence Among the Most Luminous and Massive Galaxies | Abstract |
| 10496 | Saul Perlmutter, Lawrence Berkeley National Laboratory | Decelerating and Dustfree: Efficient Dark Energy Studies with Supernovae and Clusters | Abstract |
| 10504 | Richard Ellis, California Institute of Technology | Characterizing the Sources Responsible for Cosmic Reionization | Abstract |
| 10517 | Steven Pravdo, Jet Propulsion Laboratory | Imaging Astrometrically-Discovered Brown Dwarfs | Abstract |
| 10527 | Dean Hines, Space Science Institute | Imaging Scattered Light from Debris Disks Discovered by the Spitzer Space Telescope Around 20 Sun-like Stars | Abstract |
| 10532 | Kai Noeske, University of California - Santa Cruz | Kinematics and morphology of the most massive field disk galaxies at z>1 | Abstract |
| 10546 | Andrew Fabian, University of Cambridge | The filaments of NGC1275 | Abstract |
| 10587 | Adam Bolton, Smithsonian Institution Astrophysical Observatory | Measuring the Mass Dependence of Early-Type Galaxy Structure | Abstract |
| 10596 | Luis Ho, Carnegie Institution of Washington | AGNs with Intermediate-mass Black Holes: A Test of the Black Hole-Bulge Paradigm | Abstract |
| 10602 | Jesus Maiz-Apellaniz, Space Telescope Science Institute - ESA | Complete Multiplicity Survey of Galactic O2/O3/O3.5 Stars with ACS | Abstract |
| 10608 | David Thilker, The Johns Hopkins University | Probing the star formation law in the extreme outer limits of M83, a prototypical XUV-disk galax | Abstract |
| 10624 | Derek B. Fox, California Institute of Technology | Solving the Mystery of the Short-Hard Gamma-Ray Bursts | Abstract |
| 10761 | Victoria Kaspi, McGill University | The X-ray Spectral and Optical/IR Flux Variability in Magnetars | Abstract |
| 10767 | Thomas Ayres, University of Colorado at Boulder | Further Resolving the Puzzle of Hybrid Star X-rays | Abstract |
| 10775 | Ata Sarajedini, University of Florida | An ACS Survey of Galactic Globular Clusters | Abstract |
| 10800 | Keith Noll, Space Telescope Science Institute | Kuiper Belt Binaries: Probes of Early Solar System Evolution | Abstract |
| 10846 | Michael Gladders, Carnegie Institution of Washington | The Halo Structure of RCS2-2327.4-0204 | Abstract |
| 10847 | Dean Hines, Space Science Institute | Coronagraphic Polarimetry of HST-Resolved Debris Disks | Abstract |
| 10849 | Stanimir Metchev, University of California - Los Angeles | Imaging Scattered Light from Debris Disks Discovered by the Spitzer Space Telescope around 21 Sun-like Star | Abstract |
| 10860 | Michael Brown, California Institute of Technology | The largest Kuiper belt objects | Abstract |
| 10879 | I. Neill Reid, Space Telescope Science Institute | A search for planetary-mass companions to the nearest L dwarfs - completing the survey | Abstract |
| 10889 | Roelof de Jong, Space Telescope Science Institute | The Nature of the Halos and Thick Disks of Spiral Galaxies | Abstract |
| 10928 | John Subasavage, Georgia State University Research Foundation | Calibrating Cosmological Chronometers: White Dwarf Masses | Abstract |
GO 10504 Characterizing the Sources Responsible for Cosmic Reionization
A 3-D model of cosmic reionisation at redshift z=5.81
|
The standard cartoon for the evolution of the Universe envisages three
distinct phases following the Big Bang: the `recombination era', spanning the
first few hundred thousand years, where the ionised hydrogen and helium
plasma generated by the Big Bang gives way to cooler, neutral atomic gas; the
`dark ages', lasting ~500,000 years, where the Universe is populated by
neutral absorbing gas; and `cosmic reionisation', where the first
episodes of star and black hole formation lead to photoionisation
of neutral hydrogen, and much increased transparency in the
inter(proto-)galactic medium. A key question for cosmological investigations
is the identity of the cosmic reionisers - were quasars (i.e. massive
black holes) primarily responsible, or were more conventional star clusters,
or Population III objects, the key ingredient? The aim of this proposal is to use gravitational lensing by massive clusters to probe the universe at redshifts beyond z=6. Combining NICMOS and ACS imaging with mid-infrared observations with Spitzer, the goal is to identify a representative sample of luminous objects at redshifts 6 < z < 10, laying the foundation for future more detailed investigations with JWST. |
GO 10761: The X-ray Spectral and Optical/IR Flux Variability in Magnetars
The immediate environment of a magnetar (SGR 1806-20)
|
Magnetars are neutron stars that possess extremely strong magnetic fields; measurements indicate values of 1011 Gauss or more (as compared with ~0.5 Gauss for the magnetic terrestrial field). The fields are sufficiently strong that they can induce star-quakes, producing very short-lived bursts of hard X-rays and soft gamma-rays, characteristics of the class of object known as "soft gamma repeaters". Some magnetars are pulsars, where the energy source is decay of the magnetic field, rather than accretion or rotation. The aim of the present program is to identify the source of the optical and near-infrared emission associated with magnetars. If this radiation is associated with the magnetosphere, then variations in the optical & IR should be mirrored by changes in the X-ray spectrum. This program will therefore use NICMOS on HST and ACIS on Chandra to obtain simultaneous near-IR and X-ray data for the magnetar 1E1048-5937. |
GO 10800: Kuiper Belt Binaries: Probes of Early Solar System Evolution
Composite HST image of the Kuiper Belt binary, WW31
|
The Kuiper Belt consists of icy planetoids that orbit the Sun within a broad band stretching from Neptune's orbit (~30 AU) to distance sof ~50 AU from the Sun (see David Jewitt's Kuiper Belt page for details). Over 500 KBOs are currently known out of a population of perhaps 70,000 objects with diameters exceeding 100 km. Approximately 2% of the known KBOs are binary (including Pluto, one of the largest known KBOs, regardless of whether one considers it a planet or not). This is a surprisingly high fraction, given the difficulties involved in forming such systems and the relative ease with which they can be disrupted. It remains unclear whether these systems formed from single KBOs (through collisions or 3-body interactions) as the Kuiper Belt and the Solar System have evolved, or whether they represent the final tail of an initial (much larger) population of primordial binaries. This proposal aims to use ACS/HRC images of known KBOs toidentify new binary systems. |
GO 10847: Coronagraphic Polarimetry of HST-Resolved Debris Disks
HST ACS/HRC coronagraphic images of debris disks around two nearby stars
|
The last decade has seen the identification of debris disks around a number of stars in the Solar neighbourhood. The coronagraphic capabilities available on HST have been particularly useful in this regards, since the lower background present in space-based observations offers significant advantages in detecting these low surface brightness features. Those observations are complemented by mid-infrared surveys (notably by Spitzer) of denser, warmer disks in young stars. The latter observations detect thermal emission from the dust grains, permitting some constraints to be set on the chemical composition. The present program aims to use polarimetric observations of debris disks to probe the distribution of grain sizes and the density distribution of dust in those somewhat older systems. |