This week on HST


HST Programs: January 8 - January 14 2018

Program Number Principal Investigator Program Title
14241 Daniel Apai, University of Arizona Cloud Atlas: Vertical Cloud Structure and Gravity in Exoplanet and Brown Dwarf Atmospheres
14610 Julianne Dalcanton, University of Washington A Legacy Imaging Survey of M33.
14624 Hector G. Arce, Yale University Taming the Flame: A Near-IR imaging study of the NGC 2024 (Flame Nebula) cluster
14680 Jonathan Charles Tan, The University of Virginia Kinematics of a Massive Star Cluster in Formation
14697 Bradley M Peterson, The Ohio State University A Cepheid Distance to NGC 4051
14735 Flavien Kiefer, CNRS, Institut d'Astrophysique de Paris Observation of OH in Beta Pictoris exocomets
14767 David Kent Sing, University of Exeter The Panchromatic Comparative Exoplanetary Treasury Program
14840 Andrea Bellini, Space Telescope Science Institute Schedule Gap Pilot
15073 Boris T. Gaensicke, The University of Warwick Extreme evolved solar systems (EESS)
15097 Dolon Bhattacharyya, Boston University Imaging the Extended Hot Hydrogen Exosphere at Mars to Determine the Water Escape Rate
15113 Abhijit Saha, National Optical Astronomy Observatory, AURA Extending the DA white dwarf spectrophotometric network to the Southern Hemisphere
15140 Ragnhild Lunnan, Stockholm University Resolving the Connection Between Superluminous Supernovae and Star Formation in Dwarf Galaxies
15145 Adam Riess, The Johns Hopkins University The Hubble Constant to 1%: Physics beyond LambdaCDM
15146 Adam Riess, The Johns Hopkins University A New Threshold of Precision, 30 micro-arcsecond Parallaxes and Beyond
15153 Dan Watson, University of Rochester The jets and shocks of NGC 1333: a large WFC3 mosaic of [Fe II] and H I line emission
15165 Catherine Espaillat, Boston University Connecting mass accretion and ejection in pre-main sequence stars
15166 Alex V. Filippenko, University of California - Berkeley Continuing a Snapshot Survey of the Sites of Recent, Nearby Supernovae: Cycles 25 & 26
15168 Carol A. Grady, Eureka Scientific Inc. The Nature of the Star-Grazing Bodies in a System at the Age of the Late Heavy Bombardment
15171 Bryan Jason Holler, Space Telescope Science Institute The rotation period, orbit, and mass of Eris' satellite Dysnomia
15215 Vardha N. Bennert, Cal Poly Corporation, Sponsored Programs Department A Local Baseline of the Black Hole Mass - Host Galaxy Scaling Relations for Active Galaxies
15229 Emanuele Daddi, Commissariat a l'Energie Atomique (CEA) Spectroscopic redshifts and age dating of a first statistical sample of passive galaxies at z~3
15237 Simon Joyce, University of Leicester Resolving the discrepancy in the mass determination from the gravitational redshift of Sirius B
15238 Adam L. Kraus, University of Texas at Austin The IMF to Planetary Masses Across the Milky Way
15242 Lucia Marchetti, Open University SNAPshot observations of the largest sample of lensed candidates in the Equatorial and Southern Sky identified with Herschel
15257 Patrick Hartigan, Rice University Proper Motions, Shear, Mass-Loss Rates and C-Shocks in the HH 7-11 Jet
15267 Rebecca E. A. Canning, Stanford University HST Grism observations of the highest-z massive galaxy cluster
15307 Michael D. Gladders, University of Chicago Building the SPT-HST Legacy: Imaging Massive Clusters to z=1.5
15337 Robert A. Fesen, Dartmouth College An HST Survey of Cassiopeia A's Reverse Shock, High-Velocity Ejecta, and Shocked Clouds of Pre-SN Mass Loss
15344 David Jewitt, University of California - Los Angeles Centaurs and Activity Beyond the Water Sublimation Zone
15413 Edward M. Cackett, Wayne State University Accretion disk reverberation mapping of the high Eddington rate Seyfert 1 Mrk 110

Selected highlights

GO 14241: Cloud Atlas: Vertical Cloud Structure and Gravity in Exoplanet and Brown Dwarf Atmospheres


Ground-based imaging the the very low-mass brown dwarf binary, 2MASS1207
Recent years have seen the discovery of numerous extrasolar planets. Initially, most were discovered through radial velocity monitoring; more recently the superb photometric properties of the Kepler mission have led to the discovery of numerous transiting systems. Lagging behind in numbers, but offering the greatest prospect for probing physical conditions, is direct imaging. A handful of systems with resolved planetary companions have been discovered, most notably the multi-planet system around the nearby A-type star, but they are much more massive and therefore have higher gravities. The present program aims to gain insight into their structure by comparing resolved exoplanets and higher mass, but similar temperature, brown dwarfs. Observations of isolated brown dwarfs have shown evidence for systematic variations in brightness, possibly due to dust within the atmosphere forming clouds, perhaps giving the dwarf's surface a banded appearance, similar to Jupiter. The clouds themselves may appear and disappear over relatively short timescales, leading to photometric variations at particular wavelengths. Past programs have used both Spitzer and HST to monitor spectral variability in a number of systems. The present program will use Wide-field Camera 3 to obtain time-series near-infrared grism spectra of ten brown dwarfs and high-mass exoplanets. Variations in those spectra map the atmospheric cloud structure in each system, and those variations can be examined for correlations with the mass/gravity of the parent object.

GO 14610: A Legacy Imaging Survey of M33


M33, the Triangulum Galaxy (Subaru imaging)
Messier 33, or the Triangulum galaxy, is the smallest of the three spiral galaaxies in the Local Group. Lying at a distance of ~800 kpc from the Milky Way, the system may be a satellite of the Andromeda spiral, and certainly appears to have experienced past interactions. With a mass less than half that of the Milky Way, the galaxy has a small, distinct bulge, no bar and extensive star formation regions forming spiral structure. The proximity to the Milky Way means that Hubble can resolve individual stars, albeit limited to relatively high luminosities. The present program aims to build on that capability by mapping aproximately one-third of the system. Wide Field Camnera 3 and the Advanced Camera for Surveys will be used in parallel to image 54 fields, obtaining multi-band data from the near-UV (F275W filter) through the U, B and I bands (F336W, F475W, F814W) to the near-infarred (F110W and F160W). Those data will enable investigations of the initial mass function for luminous stars; trace the detailed star formation and recent history as a function of location within the galaxy; map the dust distribution; and allow for the detection of star clusters. This dataset will complement the extensive survey of the Andromeda spiral conducted via the PHAT survey.

GO 15166: Continuing a Snapshot Survey of the Sites of Recent, Nearby Supernovae - Cycle 25 & 26


A recent supernova in M100
Supernovae mark the (spectacular) evolutionary endpoint for a subset of stellar systems. Standard models predict that they originate from massive stars and (probably) close binaries with a compact (WD, neutron star) component, but there are still some questions remaining over whether we fully understand the range of possible progenitors. The last decade has seen the development of a number of large-scale programs, usually using moderate-sized telescopes, that are dedicated to monitoring (relatively nearby galaxies, searching for new supernovae. This program builds on observations taken in several previous cycles, and aims to obtain follow-up multi-waveband images of nearby galaxies, focusing on the sites of recent supernovae. The program concentrates on systems within 20 Mpc of the Milky Way. The observations are taken well after maximum, with the aim of using the unparalleled angular resolution of WFC3 to identify the fading remnant, search for evidence for light echoes,characterise the local stellar population and perhaps determine the nature of the likely progenitor.

GO 15267: HST Grism observations of the highest-z massive galaxy cluster


A high redshift galaxy cluster, IDCS 1426 at z~1.75
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. A range of multi-wavelengthtechniques can be used to identify these systems at moderate redshifts, including using sub-millimetre telescopes to search for signatures of the Sunyaev-Zeldovich effect, where high energy electrons in the hot intercluster medium interact with radiation from the cosmic microwave background to distort the microwave spectrum, deep infrared surveys, such as the IRAC Deep Cluster Survey (IDCS) undertaken by Spitzer, and X-ray surveys, sucha s the XMM-XXL survey. The cluster targeted in this program, XLSS UJ2017, was identified through the last method, supplemented by extensive optical, near- and mid-infrared imaging that showed a significant galaxy overdensity at z~2. Subsequent sub-millimetre observations revealed an S-Z effect suggesting a cluster mass in the range 0.6-14 x 1014MSun, making it the most massive system known at this redshift. The present prorgam will use the WFC3-IR camera to obtain images in the F105W (J) and F140W (H) filters together with spectra with the G141 grism. Those observations will be used to better characterise the system.

Past weeks:
page by Neill Reid, updated 31/8/2017
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