This week on HST


HST Programs: January 2 - January 8, 2012


Program Number Principal Investigator Program Title
11539 James C. Green, University of Colorado at Boulder COS-GTO: Io's Atmospheric Response to Eclipse
11608 Nuria Calvet, University of Michigan How Far Does H2 Go: Constraining FUV Variability in the Gaseous Inner Holes of Protoplanetary Disks
12070 Julianne Dalcanton, University of Washington A Panchromatic Hubble Andromeda Treasury - I
12076 Julianne Dalcanton, University of Washington A Panchromatic Hubble Andromeda Treasury - I
12105 Julianne Dalcanton, University of Washington A Panchromatic Hubble Andromeda Treasury - I
12107 Julianne Dalcanton, University of Washington A Panchromatic Hubble Andromeda Treasury - I
12188 Jay B. Holberg, University of Arizona Tests of Extreme Physics in Very Cool White Dwarfs
12228 Glenn Schneider, University of Arizona Probing for Exoplanets Hiding in Dusty Debris Disks: Inner {<10 AU} Disk Imaging, Characterization, and Exploration
12246 Christopher W. Stubbs, Harvard University Weak Lensing Mass Calibration of SZ-Selected Clusters
12248 Jason Tumlinson, Space Telescope Science Institute How Dwarf Galaxies Got That Way: Mapping Multiphase Gaseous Halos and Galactic Winds Below L*
12286 Hao-Jing Yan, University of Missouri - Columbia Hubble Infrared Pure Parallel Imaging Extragalactic Survey {HIPPIES}
12362 Harald Ebeling, University of Hawaii The Bullet Cluster Reloaded? An in-depth study of two post-collision cluster mergers
12453 Marc Postman, Space Telescope Science Institute Through a Lens, Darkly - New Constraints on the Fundamental Components of the Cosmos
12464 Kevin France, University of Colorado at Boulder Project MUSCLES: Measuring the Ultraviolet Spectral Characteristics in Low-mass Exoplanetary Systems
12470 Kim-Vy Tran, Texas A & M Research Foundation Super-Group 1120-1202: A Unique Laboratory for Tracing Galaxy Evolution in an Assembling Cluster at z=0.37
12472 Claus Leitherer, Space Telescope Science Institute CCC - The Cosmic Carbon Conundrum
12474 Boris T. Gaensicke, The University of Warwick The frequency and chemical composition of rocky planetary debris around young white dwarfs
12476 Kem Cook, Eureka Scientific Inc. Measuring the Hubble Flow Hubble Constant
12477 Fredrick W. High, University of Chicago Weak lensing masses of the highest redshift galaxy clusters from the South Pole Telescope SZ survey
12481 Carrie Bridge, California Institute of Technology WISE-Selected Lyman-alpha Blobs: An Extreme Dusty Population at High-z
12488 Mattia Negrello, Open University SNAPshot observations of gravitational lens systems discovered via wide-field Herschel imaging
12528 Philip Massey, Lowell Observatory Probing the Nature of LBVs in M31 and M33: Blasts from the Past
12543 Robert H. Rubin, NASA Ames Research Center Fine-scale Density, Temperature, and Ionization Fluctuations: Their Effect on Abundance Determinations
12565 Ruth Peterson, SETI Institute Primordial Carbon Abundances in Extremely Metal-Poor Stars
12568 Matthew A. Malkan, University of California - Los Angeles WFC3 Infrared Spectroscopic Parallel Survey WISP: A Survey of Star Formation Across Cosmic Time
12573 Deborah Padgett, NASA Goddard Space Flight Center STIS Coronagraphy of New Debris Disks from the WISE All-Sky Survey
12585 Sara Michelle Petty, University of California - Los Angeles Unveiling the Physical Structures of the Most Luminous IR Galaxies Discovered by WISE at z>1.6
12603 Timothy M. Heckman, The Johns Hopkins University Understanding the Gas Cycle in Galaxies: Probing the Circumgalactic Medium
12616 Linhua Jiang, Arizona State University Near-IR Imaging of the Most Distant Spectroscopically-Confirmed Galaxies in the Subaru Deep Field
12748 Martin C. Weisskopf, NASA Marshall Space Flight Center Joint Chandra and HST Monitoring of the Crab Nebula
12792 Matthew M Knight, Lowell Observatory High Spatial Resolution Photometric Imaging of the Area Around the Nucleus of C/2011 W3 Lovejoy

Selected highlights

GO 12105: 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" is conducting a multi-waveband survey of approximately one third of disk and bulge, focusing on the north-east quadrant. Observations extend over Cycles 19, 20 and 21, and will provide a thorough census of upper main-sequence stars, open clusters, associations and star forming regions, matching the stellar distribution against the dust and gas distribution.
GO 12248: How Dwarf Galaxies Got That Way: Mapping Multiphase Gaseous Halos and Galactic Winds Below L*


A computer simulation of galactic gas accretion and outflow
Galaxy formation, and star formation within a galaxy, requires the presence of gas. The detailed evolution of individual galactic systems therefore depends on how gas is accreted, recycled, circulated through the halo and, perhaps, ejected back into the intergalactic medium. Tracing that evolutionary history is difficult, since gas passes through many different phases, some of which are easier to detect than others. During accretion and, probably, subsequent recycling, the gas is expected to be reside predominantly at high temperatures. The most effective means of detecting such gas is through ultraviolet spectroscopy, where gas within nearby systems can be detected as absorption lines superimposed on the spectra of more distant objects, usually quasars. The present program is using the Cosmic Origins Spectrograph to observe low- to moderate redshift QSOs (0.1 < z < 1) that lie at small angular separations from sub-L* mass galaxies (0.02 < M/L* < 0.3) at redshifts between z=0.01 and 0.06. The sightlines run through the halos of the galaxies, and the QSOs therefore provide a pencilbeam backlight that probes hot gas in the foreground systems.

GO 12573: STIS Coronagraphy of New Debris Disks from the WISE All-Sky Survey


HST image of the face-on debris disk in the G2 dwarf, HD 107146
Planet formation occurs in circumstellar disks around young stars. Most of the gaseous content of those disks dissipates in less than 10 million years, leaving dusty debris disks that are detectable through reflect light at near-infrared and, to a lesser extent, optical wavelengths. The structure of those disks is affected by massive bodies (i.e. planets and asteroids), which, through dynamical interactions and resonances, can produce rings and asymmetries. Analysis of the rangle of morphological structure in these systems provides insight into the distribution of properties of planetary systems. HST currently provides the only means of achieving the high-contrast required for the detection of scattered light from these disks in the presence of the bright parent stars. While many such systems have been observed, only a relatively small number of disks have been imaged successfully at visual or near-infrared wavelengths. The present program aims to expand the sample by targetting six solar-type stars that are known to have circumstellar disks based on mid-infrared observations with WISE, the Wide-field Infrared Survey Explorer. This sample constitutes the brightest new discoveries, and therefore the most likely candidates for detection by Hubble. The present proposal will use the occulting bar on the Space Telescope Imaging Spectrograph to carry out coronagraphic imaging at visual wavelengths.

GO 12748: Joint Chandra and HST Monitoring of the Crab Nebula


The Crab Nebula
Messier 1, the Crab Nebula, provides astronomy with one of its iconic images. The remnant of a bright supernova observed in 1054 by Arabian and Chinese astronomers, the Crab was first recorded in 1731 by the English astronomer, John Bevis, thirt-seven years before Messier compiled his catalogue of non-comets. The energy source for the gaseous emission is the neutron star that lies in the centre of nebulosity, and was one of the first pulsars to be identified. The Crab is also a source of high energy emission, including radiation at X-ray and gamma ray wavelengths. Overall, this system plays a crucial role in aiding our understanding of post-supernova evolutionary processes. However, there are still some notable undertainties in the detailed processes within even this system. In particular, in September of 2010 the Crab surprised the astronomial community by producing a powerful flare at gamma-ray wavelengths that persisted for 4 days (see GO 12381 ).A second flare of similar magnitude occurred in May, 2011. Observations taken during the 2010 flare by HST and Chandra provided some insight into the effects of the flare, but analysis was hampered by the absence of a comparison set of pre-outburst images of comparable resolution and depth. The present program aims to address that issue through coordinated monitoring of the Crab at X-ray and optical wavelengths. Tne Advanced Camera for Surveys on HST will be used to take images in the F550M filter at 6 epochs in 2012, with the observations timed to be within 10 days of X-ray images taken by Chandra using the AXAF CCD Imaging Spectrometer. These data will establish a reference set should a further flare occur.

Past weeks:
page by Neill Reid, updated 8/12/2011