This week on HST


HST Programs: August 4 - August 10, 2014

Program Number Principal Investigator Program Title
12884 Harald Ebeling, University of Hawaii A Snapshot Survey of The Most Massive Clusters of Galaxies
12893 Ronald L Gilliland, The Pennsylvania State University Study of Small and Cool Kepler Planet Candidates with High Resolution Imaging
12969 Peter Garnavich, University of Notre Dame Global Properties Are Not Enough: Probing the Local Environments of Type Ia Supernovae
13117 Andrew J. Levan, The University of Warwick A Chandra/HST survey of dark gamma-ray bursts and their hosts
13291 Masao Hayashi, National Astronomical Observatory of Japan (NAOJ) Resolving internal structures of the progenitors of early-type galaxies in a vigorously forming cluster at z=2.5
13292 Remy Indebetouw, The University of Virginia Dissecting star formation in N159
13306 Gillian Wilson, University of California - Riverside Is the Size Evolution of Massive Galaxies Accelerated in Cluster Environments?
13321 Pierre Guillard, Institut d'Astrophysique Spatiale COS Spectroscopy of the Stephan's Quintet Giant Shock
13332 Seth Redfield, Wesleyan University A SNAP Survey of the Local Interstellar Medium: New NUV Observations of Stars with Archived FUV Observations
13334 Adam Riess, The Johns Hopkins University The Longest Period Cepheids, a bridge to the Hubble Constant
13344 Adam Riess, The Johns Hopkins University A 1% Measurement of the Distance Scale with Perpendicular Spatial Scanning
13352 Matthew A. Malkan, University of California - Los Angeles WFC3 Infrared Spectroscopic Parallel Survey WISP: A Survey of Star Formation Across Cosmic Time
13358 Klaus Werner, Eberhard Karls Universitat, Tubingen Trans-iron group elements in the hot white dwarf RE 0503-289
13361 William P. Blair, The Johns Hopkins University Discovering and Characterizing the Young Supernova Remnant Population in M101
13365 Martin A Cordiner, Catholic University of America Probing the nature of small-scale structure towards rho Oph stars: A new avenue in diffuse interstellar band research
13377 Andrea Mehner, European Southern Observatory - Chile Essential UV Observations of Eta Carinae's Change of State
13381 Marshall Perrin, Space Telescope Science Institute STIS Coronagraphy of Four Young Debris Disks Newly Uncovered from the NICMOS Archive
13386 Steven A. Rodney, The Johns Hopkins University Frontier Field Supernova Search
13388 Gregory James Schwarz, American Astronomical Society Fundamental properties of novae outburst: Coordinated HST and XMM ToO observations
13398 Christopher W. Churchill, New Mexico State University A Breakaway from Incremental Science: Full Characterization of the z<1 CGM and Testing Galaxy Evolution Theory
13401 Claes Fransson, Stockholm University A 3D view of the SN 1987A Ejecta
13412 Tim Schrabback, Universitat Bonn, Argelander Institute for Astronomy An ACS Snapshot Survey of the Most Massive Distant Galaxy Clusters in the South Pole Telescope Sunyaev-Zel'dovich Survey
13435 Matteo Monelli, Instituto de Astrofisica de Canarias Multiple populations in external globular glusters: the Fornax dSph, the LMC, and the SMC
13442 R. Brent Tully, University of Hawaii The Geometry and Kinematics of the Local Volume
13452 Matthew Hayes, Stockholm University Coupling the emission of ionizing radiation and Lyman alpha
13459 Tommaso L. Treu, University of California - Los Angeles The Grism Lens-Amplified Survey from Space {GLASS}
13462 Brian E. Wood, Naval Research Laboratory Tracking the Winds of Red Giants from the Star to the ISM
13484 Bo Reipurth, University of Hawaii Structure, Excitation, and Evolution of Shocks: A Multi- Wavelength Study of Herbig-Haro 1/2
13496 Jennifer Lotz, Space Telescope Science Institute HST Frontier Fields - Observations of MACSJ0416.1-2403
13517 Matthew A. Malkan, University of California - Los Angeles WFC3 Infrared Spectroscopic Parallel Survey WISP: A Survey of Star Formation Across Cosmic Time

Selected highlights

GO 12893: Study of Small and Cool Kepler Planet Candidates with High Resolution Imaging


The Kepler satellite
Kepler is a NASA Discovery-class mission, designed to search for extrasolar planets by using high-precision photometric observations to detect transits. Launched on 7 March 2009, Kepler continuously monitored ~100,000 (mainly) solar-type stare within a ~100 square degree region in Cygnus for more than 4 years. Routine observations ceased on May 11 2013 when a second reaction wheel failed; efforts are currently under way to examine the options for restoring observations. Regardless, the mission has been an astounding success. Ground-based observations have successfully detected a couple of dozen transiting planets (e.g. HD 209458); almost all are "hot jupiters", gas giants on short-period orbits which produce a photometric dip of ~10-2 with a period of a few days, with a smattering of neptune-sized "super-Earths". Kepler, in contrast, has identified more than 2,700 exoplanet candidates around over 2,000 candidate host stars. More significantly, the exquisite precision of Kepler's photometric observations enables it to detect the 0.01% transit signature of earth analogues in these systems. A subset of stellar binaries provide one of the main sources of confusion in searching for planetary transits, since "grazing" transits can mimic the planetary signature. This is particularly an issue with Kepler, since the optical system is designed to provide a broad psf, spreading the stellar flux over a large area on the detector to allow high photometric accuracy. As a result, faint eclipsing stellar binaries will contribute to the source counts. Moreover, since the target field is (intentionally) within the Milky Way, there is a significant potential for unresolved stars within the (relatively broad) Kepler psf to increase the total signal, and hence dilute the depth of transits, giving the appearance of a smaller diameter exoplanet. This program is using the high spatial resolution imaging provided by HST to study a subset of the Kepler Earth-like candidates to assess the potential of this effect.

GO 13401: A 3D view of the SN 1987A Ejecta

November 2003 HST image of the SN1987A gaseous ring SN1987A, in the Large Magellanic Cloud, is (as far as we know) the nearest supernova to the Sun since Kepler's supernova of 1604. While its eruption, in January 1987, predated HST's launch by over 3 years, the remnant has been a regular observational target since the installation of COSTAR at the first servicing mission. Those high resolution observations have revealed the development, and evolution, of extensive, intricate structures as the blast wave from SN1987A encounters the surrounding interstellar medium. In particular, a striking circum-remnant ring has developed, with numerous hot spots stimulated by the fastest moving debris. HST has been monitoring developments in the supernova remnant since Cycle 1, obtaining optical and near-infrared images with almost every imaging instrument installed over the apst 2 decades. The most recent such program, GO 13405, uses the UVIS and IR channels on WFC3 to continue monitoring the development of those features, using a series of observations that are co-ordinated with the Chandra X-ray Observatory. The present program complements those imaging observations with optical spectroscopy of the ejecta with the Space Telescope Imaging Spectrograph, STIS. Alignng the STIS slit along filaments will allow measurement of the line of sight velocity structure, mapping the spatial distribution of the debris and probing the presence and structure of shocks.

GO 13412: An ACS Snapshot Survey of the Most Massive Distant Galaxy Clusters in the South Pole Telescope Sunyaev-Zel'dovich Survey


The South Pole Telescope at the Amundsen-Scott South Pole Station
The overwhelming majority of galaxies in the universe are found in clusters. As such, these systems offer an important means of tracing the development of large-scale structure through the history of the universe. Galaxy clusters can be identified at moderate redshifts by searching for signatures of the Sunyaev-Zeldovich effect: high energy electrons in the hot intercluster medium interact with radiation from the cosmic microwave background to distort the microwave spectrum. The South Pole Telescope is a 10-metre microwave/millimetre telescope located at Amundsen-Scott South Pole Station on the Antarctiva high plateau, close to the geographic South Pole. That telescope has been used to search for galaxy clusters. As intense mass concentrations, these systems are highly efficient gravitational lenses, capable of concentrating and magnifying light from background high redshift galaxies to allow detailed spectropic investigations of star formation in the early universe. Hubble imaging has already revealed lensed arcs and detailed sub-structure within a handful of rich clusters. At the same time, the lensing characteristics provide information on the mass distribution within the lensing cluster. The present program is using the Wide Field Camera on the Advanced Camera for Surveys to obtain SNAPshot images of up to 120 of the most massive clusters so far detected by the SPT. The HST data will be analysed for weak lensing signatures that can be combined with X-ray, IR and optical observations to constrain the mass estimates for these clusters.

GO 13496: HST Frontier Fields - Observations of MACSJ0416.1-2403


The Frontier Fields cluster, MACSJ0416.1-2403
The overwhelming majority of galaxies in the universe are found in clusters. As such, these systems offer an important means of tracing the development of large-scale structure through the history of the universe. Moreover, as intense concentrations of mass, galaxy clusters provide highly efficient gravitational lenses, capable of concentrating and magnifying light from background high redshift galaxies to allow detailed spectropic investigations of star formation in the early universe. Hubble imaging has already revealed lensed arcs and detailed sub-structure within a handful of rich clusters. At the same time, the lensing characteristics provide information on the mass distribution within the lensing cluster. The present program builds on the highly successful CLASH program,which used 17-colour ACS/WFC3 images to map 25 galaxy clusters, tracing the mas profile and the dark matter distribution. in addition, the observations identified several lensed galaxies at redshifts that enter the JWST domaine, with the most distant object lying at a redshift z~11, within a few hundred million years of the Big Bang. The Frontier Fields program is a large-scale Director's Discretionary program that capitalises on the latter characteristic by targeting 4-6 strong-lensing galaxy clusters for very deep optical and near-infrared imaging. WFC3 and ACS will be used to observe the clusters, with simultaneous imaging obtained in parallel of a nearby "blank" field. Since the observations need to made at a specific orientation, they are being taken in two sets, ~6 months apart, alternating between detectors. MACSJ0416.1-2403 at z=0.396 is the second target: at the first epoch, the cluster was imaged with WFC3-IR, with ACS obtaining optical data on the nearby blank field; the second epoch observations switch cameras, with ACS on the cluster and WFC3-IR on the parallel field.

Past weeks:
page by Neill Reid, updated 18/8/2014
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