This week on HST


HST Programs: June 13 - June 19, 2016

Program Number Principal Investigator Program Title
13665 Bjoern Benneke, California Institute of Technology Exploring the Diversity of Exoplanet Atmospheres in the Super-Earth Regime
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
14079 Matthew James Hayes, Stockholm University Unveiling the Dark Baryons II: the First Sample of OVI Emission Imaging
14081 Thierry Lanz, Observatoire de la Cote d'Azur Probing Supernovae Chemical Yields in Low Metallicity Environments with UV Spectroscopy of Magellanic Cloud B-type Stars
14083 Ismael Perez-Fournon, Instituto de Astrofisica de Canarias The nature and environment of the most luminous starburst galaxies at redshift > 5
14092 Susan D. Benecchi, Planetary Science Institute Collisional Processing in the Kuiper Belt and Long-Range KBO Observations by New Horizons
14095 Gabriel Brammer, Space Telescope Science Institute - ESA Calibrating the Dusty Cosmos: Extinction Maps of Nearby Galaxies
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
14135 Gordon T. Richards, Drexel University Are High-Redshift Spectroscopic Black Hole Mass Estimates Biased?
14163 Mickael Rigault, Humboldt Universitat zu Berlin Honing Type Ia Supernovae as Distance Indicators, Exploiting Environmental Bias for H0 and w.
14175 Paul Goudfrooij, Space Telescope Science Institute Resolving the Nature of the Stellar Halo of the Sombrero, the Nearest Giant Early-Type Spiral Galaxy
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
14199 Patrick Kelly, University of California - Berkeley Refsdal Redux: Precise Measurements of the Reappearance of the First Supernova with Multiple Resolved Images
14203 James Miller-Jones, Curtin University Confirmation of the First Ultracompact Black Hole X-ray Binary
14210 Russell Julian Smith, Durham Univ. Improved masses for two new low-redshift strong lens galaxies: Do giant ellipticals really have a heavy IMF?
14219 John P. Blakeslee, Dominion Astrophysical Observatory Homogeneous Distances and Central Profiles for MASSIVE Survey Galaxies with Supermassive Black Holes
14220 Trent J. Dupuy, University of Texas at Austin Mapping the Substellar Mass-Luminosity Relation Down to the L/T Transition
14251 Amy E. Reines, National Optical Astronomy Observatory, AURA The Structures of Dwarf Galaxies Hosting Massive Black Holes
14258 Howard E. Bond, The Pennsylvania State University The Nature of SPIRITS Mid-Infrared Extragalactic Transients
14268 Nicolas Lehner, University of Notre Dame Project AMIGA: Mapping the Circumgalactic Medium of Andromeda
14272 Walter Peter Maksym, Smithsonian Institution Astrophysical Observatory Long-Term Ultraviolet Spectroscopy of a Tidal Disruption Event at only 90 Mpc
14327 Saul Perlmutter, University of California - Berkeley See Change: Testing time-varying dark energy with z>1 supernovae and their massive cluster hosts
14353 Andrew S. Fruchter, Space Telescope Science Institute The Astrophysics of the Most Energetic Gamma-Ray Bursts
14456 Mark Brodwin, University of Missouri - Kansas City Determining the Role of Merging in the Growth of the Galaxy Cluster Population in the Massive and Distant Clusters of WISE Survey
14491 Keith S. Noll, NASA Goddard Space Flight Center Trojan Binary Candidate: A Slow-Rotating Mission Target
14516 Robert M. Quimby, San Diego State University UV Spectroscopy of the Superluminous Supernova Gaia16apd

Selected highlights

GO 14069: Searching For Multiple Populations in Massive Young and Intermediate Age Clusters


HST image of the LMC cluster, NGC 1866
Globular clusters are remnants of the first substantial burst of star formation in the Milky Way. With typical masses of a few x 105 solar masses, distributed among several x 106 stars, the standard picture holds that these are simple systems, where all the stars formed in a single starburst and, as a consequence, have the same age and metallicity. Until recently, the only known exception to this rule was the cluster Omega Centauri, which is significantly more massive than most clusters and has both double main sequence and a range of metallicities among the evolved stars. Over the past 5-10 years, Omega Cen has been joined by numerous other Galactic clusters, including NGC 2808, which shows evidence for three distinct branches to the main sequence, NGC 1851, 47 Tucanae and NGC 6752 - all relatively massive clusters. In almost all cases, the complexity of these systems has only emerged through the high precision observations possible with HST. Hubble is now being turned towards clusters in our nearest neighbour galaxies, the Large and Small Magellanic Clouds. Previousl observations have obtained of the massive cluster NGC 1846. The present program aims to extends coverage to a dozen other clusters, including NGC 419, 1783, 1850 and 1866. The clusters span a wide range of ages, from ~100 Myrs to close to 10 Gyrs. The WFC3-UVIS camera will be used to obtain UV (F343N, F336W) and blue-band (F438W) images to search for evidence of multiple populations in the colour-magnitude diagrams.

GO 14163: Honing Type Ia Supernovae as Distance Indicators, Exploiting Environmental Bias for H0 and w.


Supernova in M101
Supernovae have long attracted the attention of both amateur and professional astronomers as a means of studying the violent eruption and death of massive stars and degenerates. However, in the last decade they have also acquired considerable importance as distance indicators, tracing the expansion of the universe to redshifts well beyond the reach of more conventional yardsticks, such as cepheids, and providing a key underpinning for the hypothesised existence of dark energy. Understanding the supernovae themselves, and, in particular, their progenitors, is key to accurately interpreting their luminosities and distances. Recent observations have suggested that there may be a correlation between the brightnesses of Type Ia supernovae and some characteristics of their local environment; specifically, supernovae found in close proximity to star formation appear to be sub-luminous. The present SNAP program uses the UVIS camera on WFC3 to image the locations of supernovae that have been used to map the Hubble flow, and will use the UV-to-optical flux ratio to characterise the local environment, potentially offering a means of tightening the distribution in the Hubble diagram.

GO 14175: Resolving the Nature of the Stellar Halo of the Sombrero, the Nearest Giant Early-Type Spiral Galaxy


Hubble imaging of the Sombrero galaxy, Messier 104
The subdwarf stars that populate the Galactic halo are generally recognised as fossil remnants of the first episode of substantial star formation to afflict the Milky Way galaxy. These stars are metal-poor relatiev to the Sun, with abundances as low [Fe/H]=-4 (one ten thousandth the solar abundance). The structure and density distribution of our own halo has been inferred partly from deep starcounts, partly from globular cluster systems and partly from the kinematics of local subdwarfs; most analyses favour a near-spherical system with density r-3.5. The Milky Way is (obviously) a spiral system, and observations have been obtained of stars in the halo of several other nearby spiral systems, notably Andromeda (M31) and triangulum (M33). The present program aims to extend observations to the halo of the nearest early-type galaxy, the lenticular Sombrero galaxy, lying at a distance of 9 Mpc. The program will obtain ddeep imagign at two locations along the minor axis, using the Advanced Camera for Surveys and Wide Field Camera 3 to obtain F606W and F814W data, enabling the constructing of (V, (V-I)) colour magnitude diagrams for the red giant stars, probing the metallicity distribution in the Sombrero's halo.

GO 14181: A Snapshot WFC3 IR Survey of Spitzer/Hershel-Identified Protostars in Nearby Molecular Clouds


An image of the Orion Nebula superimposed on the 13CO map of Orion A (from this link ).
Giant molecular cloud complexes serve as nurseries for star formation. Deeply embedded in dust and gas, young stars are generally extremely difficult to detect at optical wavelengths. Consequently, these complexes have been subject to extensive scrutiny at near- and mid-infrared wavelengths, initially through ground-based observing campaigns and more recently by the Spitzer and Herschel space missions. Those observations have resulted in the identification of numerous embedded sources, young stellar objects (YSOs) that are still accreting from the surrounding molecular gas .he present proposal aims to follow up on those discoveries by obtaining WFC3-IR SNAPs of candidate protostars in several molecular cloud complexes. These observations will provide an excellent complement to Spitzer and Herschel since, while HST cannot offer either the same areal coverage or sensitivity at mid-infrared wavelegths, the imaging has a resolution close to 0.1 arcsecond, an order of magnitude higher than the Spitzer images. The observations are therefore capable of detecting very faint companions, with luminosities consistent with sub-stellar masses, as well as identifying jets and outflows associated with the star formation process. The present program is using the F160W filter to obtain H-band images and determine the true nature of these objects.

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