This week on HST


HST Programs: September 12 - September 18, 2016

Program Number Principal Investigator Program Title
13760 Derck L. Massa, Space Science Institute Filling the gap --near UV, optical and near IR extinction
14069 Nate Bastian, Liverpool John Moores University Searching For Multiple Populations in Massive Young and Intermediate Age Clusters
14076 Boris T. Gaensicke, The University of Warwick An HST legacy ultraviolet spectroscopic survey of the 13pc white dwarf sample
14077 Boris T. Gaensicke, The University of Warwick The frequency and chemical composition of rocky planetary debris around young white dwarfs: Plugging the last gaps
14084 Seth Redfield, Wesleyan University Connecting Earth with its Galactic Environment: Probing Our Interstellar Past Along the Historical Solar Trajectory
14091 Aaron J. Barth, University of California - Irvine Bulge structure and kinematics in an extreme spiral galaxy hosting megaparsec-scale radio jets.
14096 Dan Coe, Space Telescope Science Institute - ESA RELICS: Reionization Lensing Cluster Survey
14098 Harald Ebeling, University of Hawaii Beyond MACS: A Snapshot Survey of the Most Massive Clusters of Galaxies at z>0.5
14104 Jesus Maiz Apellaniz, Centro de Astrobiologia (CAB, CSIC-INTA) The optical-UV extinction law in 30 Doradus
14119 Luciana C. Bianchi, The Johns Hopkins University Understanding Stellar Evolution of Intermediate-Mass Stars from a New Sample of SiriusB-Like Binaries
14122 Lise Christensen, University of Copenhagen, Niels Bohr Institute Unveiling stellar populations in absorption-selected galaxies
14150 Morgan Fraser, University of Cambridge Searching for the disappearance of the progenitor of the unique SN 2009ip
14155 Jason S. Kalirai, Space Telescope Science Institute Using Stellar Evolution as a Clock to Watch the Dynamical Evolution of a Globular Cluster
14163 Mickael Rigault, Humboldt Universitat zu Berlin Honing Type Ia Supernovae as Distance Indicators, Exploiting Environmental Bias for H0 and w.
14178 Matthew A. Malkan, University of California - Los Angeles WFC3 Infrared Spectroscopic Parallel Survey: The WISP Deep Fields
14181 S Thomas Megeath, University of Toledo A Snapshot WFC3 IR Survey of Spitzer/Hershel-Identified Protostars in Nearby Molecular Clouds
14191 Andrew A. Cole, University of Tasmania The Star Formation History and Proper Motion of NGC 6822
14209 Brian Siana, University of California - Riverside The Final UV Frontier: Legacy Near-UV Imaging of the Frontier Fields
14219 John P. Blakeslee, Dominion Astrophysical Observatory Homogeneous Distances and Central Profiles for MASSIVE Survey Galaxies with Supermassive Black Holes
14237 Nial Rahil Tanvir, University of Leicester r-process kilonova emission accompanying short-duration GRBs
14247 Jimmy A. Irwin, University of Alabama Confirmation of an Intermediate-Mass Black Hole in an Extragalactic Globular Cluster
14269 Nicolas Lehner, University of Notre Dame Just the BASICs: Linking Gas Flows in the Circumgalactic Medium to Galaxies
14339 Pierre Kervella, Observatoire de Paris The parallax and mass of the binary classical Cepheid V1334 Cyg
14343 Nitya Kallivayalil, The University of Virginia Proper Motion and Internal Kinematics of the SMC: are the Magellanic Clouds bound to one another?
14597 Jay Farihi, University College London An Ultraviolet Spectral Legacy of Polluted White Dwarfs
14675 Julia Christine Roman-Duval, Space Telescope Science Institute - ESA Metal Evolution and TrAnsport in the Large Magellanic Cloud (METAL): Probing Dust Evolution in Star Forming Galaxies
14695 S Thomas Megeath, University of Toledo WFC3 Imaging of 24 um Dropout Protostars in Orion
14706 Eilat Glikman, Middlebury College Testing the Triggering Mechanism for Luminous, Radio-Quiet Red Quasars in the Clearing Phase: A Comparison to Radio-Loud Red Quasars
14793 Jacob L. Bean, University of Chicago The First Precise Atmospheric Metallicity Measurement for a Sub-Jovian Exoplanet

Selected highlights

GO 14084: Connecting Earth with its Galactic Environment: Probing Our Interstellar Past Along the Historical Solar Trajectory


The Sun's path through the local interstellar medium
The Sun's motion around the Galaxy takes it through a range of environments within the interstellar medium.At the present time the Sun lies on the edge of the "Local Bubble", a region of very low gas density. Its recent motions took it through a cloud of interstellar material that is moving radially outward within the disk. It is not clear how, or indeed whether, the local ISM has a significant effect on solar heliosphere and the individual bodies in the Solar System, including Earth. The present program aims to explore that issue through high resolution ultraviolet spectroscopy of eight stars that lie in the direcion of the Sun's past motion. These stars serve as backlights to the local ISM, whose component elements manifest themselves by absorbing the stellar light. The observations will use the Cosmic origins Spectrograph to search for characteristics features due to ionised Fe II and Mg II.

GO 14209: The Final UV Frontier: Legacy Near-UV Imaging of the Frontier Fields


The Frontier Fields cluster, Abell S1063
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. Hubble is currently undertaking deep imaging observations of up to 6 galaxy clusters as part of the Frontier Fields Director's Time program. Those observations have provided a basis for several synergistic programs, including GO 13389, which covered three clusters (MACSJ0717, MACSJ1149 and Abell 2744), supplementing the visual and near-infrared data in the core Frontier Fields program with deep imaging at near-UV wavelengths using the F275W and F336W filters on WFC3's UVIS camera. At the same time, the ACS-WFC camera is being used to obtain blue (F435W) and red (F606W) data on the associated parallel field from the Frontier Fields program. The present program extends coverage to the three remaining clusters (Abell 370, Abell S1063 and MACSJ0416) The UV data will enable investigation of the star formation rates and morphologies of moderate redshift galaxies, 0.5 < z < 3, lying behind the galaxy cluster. Combined with the Frontier Fields photometry, these data will enable more accurate photometric redshift determinations, probe Lyman escape fractions and offer the prospect of mapping the spatial distribution of star formation in lensed systems.

GO 14269: Just the BASICs: Linking Gas Flows in the Circumgalactic Medium to Galaxies


A computer simulation of galactic gas accretion and outflow
Galaxy formation, and the overall history of star formation within a galaxy, clearly demands the presence of gas. The detailed evolution 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. Extensive observations of galaxies at modest redshift (0.15 < z < 0.35) have shown that material extends to radii of hundreds of kpc, with a total mass in metals that is at least comparable with the mass in the central galaxy. The structures appear to show a bimodal metallicity distribution, with a metal-rich (~40% solar) component that may reflect winds and outflows, and a metal-poor (3% solar) component that may trace cold accretion streams. The present program aims to use ACS to image 14 QSO fields that harbour well-characterised circum-galactic medium absorbers, with the aim of measuring the geometry and morphology of the parent galaxies and searching for correlations with the gaseous properties.

GO 14793: The First Precise Atmospheric Metallicity Measurement for a Sub-Jovian Exoplanet


An artist's impression of the exoplanet Hap P 11b matched against Neptune for size
The standard model for planet formation hypothesises the initial formation of a relatively dense core, with subsquent accretion of gaseous material to form the gas and ice giants found in our solar system and other stellar systems. Snce the accreted material is dominated by volatiles (mainly hydrogen), that model predicts that smaller planets should have higher metallicity atmospheres. Transiting exoplanets are an invaluable resource for testing this hypothesis since their brief transit across the face of the primary star not only gives a direct measurement of their diameter, but also can provide an opportunity to sample the chemical composition of the atmosphere. Following Kepler, more than 2000 such systems are now known, extending to small terrestrial planets; nonetheless, much of the information gleaned by the explanet community comes from earlier discoveries based on ground-based monitoring. This simply reflects the fact that those surveys targeted bright stars, and therefore give the spectral analysts more photons to work with during transit. One of the most interesting systems is HAT-P-11b, a Neptune-sized planet orbiting a K4 dwarf lying some 37 parsecs from the Sun. Past HST and Spitzer observations rsulted in the detection in water at wavelengths between 1.1 and 1.7 microns in what seems to be a relatively cloud-free atmosphere. The present program aims to build on those observations by probing shorter wavelengths, measuring the metallicity of the atmosphere.

Past weeks:
page by Neill Reid, updated 23/12/2014
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