This week on HST


HST Programs: January 22 - January 28 2018

Program Number Principal Investigator Program Title
14624 Hector G. Arce, Yale University Taming the Flame: A Near-IR imaging study of the NGC 2024 (Flame Nebula) cluster
14656 Ivana Orlitova, Astronomical Institute, Academy of Sciences of CR How does ionizing radiation escape from galaxies?
14697 Bradley M Peterson, The Ohio State University A Cepheid Distance to NGC 4051
14734 Nitya Kallivayalil, The University of Virginia Milky Way Cosmology: Laying the Foundation for Full 6-D Dynamical Mapping of the Nearby Universe
14735 Flavien Kiefer, CNRS, Institut d'Astrophysique de Paris Observation of OH in Beta Pictoris exocomets
14753 Claes Fransson, Stockholm University Supernova 1987A at 30 years
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)
15075 Jay Christopher Howk, University of Notre Dame The CGM of Massive Galaxies: Where Cold Gas Goes to Die?
15113 Abhijit Saha, National Optical Astronomy Observatory, AURA Extending the DA white dwarf spectrophotometric network to the Southern Hemisphere
15118 Benny Trakhtenbrot, Eidgenossiche Technische Hochschule (ETH) TESTING THE RELEVANCE OF MERGERS AND ENVIROMENT FOR THE FASTEST GROWING BLACK HOLES IN THE MOST INTENSELY STAR FORMING GALAXIES
15132 Harald Ebeling, University of Hawaii Beyond MACS: A Snapshot Survey of the Most Massive Clusters of Galaxies at z>0.5
15133 Peter Erwin, Max-Planck-Institut fur extraterrestrische Physik Solving the Mystery of Galaxy Bulges and Bulge Substructure
15136 Yuri I. Izotov, Ukrainian National Academy of Sciences, MAO Lyman alpha emission in nearby star-forming galaxies with the lowest metallicities and the highest [OIII]/[OII] ratios
15140 Ragnhild Lunnan, Stockholm University Resolving the Connection Between Superluminous Supernovae and Star Formation in Dwarf Galaxies
15141 Tom Megeath, University of Toledo The 6 pc DASH: A WFC3 1.6 micron Survey of the Orion Integral Shaped Filament
15145 Adam Riess, The Johns Hopkins University The Hubble Constant to 1%: Physics beyond LambdaCDM
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
15166 Alex V. Filippenko, University of California - Berkeley Continuing a Snapshot Survey of the Sites of Recent, Nearby Supernovae: Cycles 25 & 26
15189 David John Wilson, The University of Warwick Post Common Envelope Binaries as probes of M dwarf stellar wind and habitable zone radiation environments
15200 Duncan Farrah, Virginia Polytechnic Institute and State University A case study of an extremely luminous, highly spatially extended starburst only 1.7Gyr after the Big Bang
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
15238 Adam L. Kraus, University of Texas at Austin The IMF to Planetary Masses Across the Milky Way
15300 Thomas R. Ayres, University of Colorado at Boulder Ecliptic-poles Stellar Survey (EclipSS)
15307 Michael D. Gladders, University of Chicago Building the SPT-HST Legacy: Imaging Massive Clusters to z=1.5
15415 Or Graur, Harvard University One last peek at SN 2015F

Selected highlights

GO 14734: Milky Way Cosmology: Laying the Foundation for Full 6-D Dynamical Mapping of the Nearby Universe


The low-mass dwarf galaxy, Leo II
The Milky Way, M31 and M33 are the three largest galaxies in the Local Group. That system, however, includes more than 25 other members, with the majority being dwarf spheroidal galaxies that are satellites of either M31 or the Milky Way. Those galaxies have old, evolved stellar populations, and even the most prominent have masses that are less than a few x 107 MSun, or 10-4 that of the Milky Way. All of these galaxies are moving in the potential set by the overall Local Group system, but dominated by M31 and the Milky Way. Determining full space motions for the dwarfs therefore provide a means of constraining that potential. Even though the galaxies, and their brightest stellar constituents, are faint, measuring radial velocity is a relatively straightforward procedure. Deriving tangential motions is not, since the typical proper motions of these systems are a few mas/year at best. The present proposal aims to capitalise on the exceptional resolution and high stability of HST to address this issue. Wide Field Camera 3 and the Advanced Camera for Surveys will be used to obtain first epoch observations of the 32 known dwarf galaxies within 420 kpc. that currently lack such data. These observations will lay the foundation for future observations with both HST and future missions, including JWST and WFIRST.

GO 14753: Supernova 1987A at 30 years

Evolution of a supernova remnant 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. Over the past few cycles, the hotspots are fusing as the shock fully enters the ring, and photons from these regions are exciting previously hidden gas outside the ring, illuminating mass lost from the progenitor before the explosion. The inner debris are now well resolved, and clearly aspherical. By now, the blast wave has passed the inner ring, which is starting to fade, and is interacting with more distant materials. The present program will use the Cosmic Origins Spectrograph and the Space Telescope Imaging Spectrograph to obtain ultraviolet and optical spectra of the ejecta and the ring, probing the composition and enabling detailed modelling of nucleosynthesis. Overall, these observations provide crucial insight into the earliest stages of formation of a supernova remnant.

GO 15075: The CGM of Massive Galaxies: Where Cold Gas Goes to Die?


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 is tied very closely to how gas is accreted, recycled, circulated through the halo and disk, 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 survey cold gas in the circumgalactic medium for a large sample of luminous red galaxies at redshifts z~0.5. The targets are drawn from the SDSS-III DR13 CMASS sample. All of these systems have background quasars lying at small angular separations, corresponding to linear separatiosn of ~150 kpc at distance of the target galaxies. Ground-based observations of those quasars indicate the presence of ionised magnesium (MgII) absorption due to halo gas associated with the foreground galaxy. COS will be used to probe the presence of hydrogen, through detections of the Lyman limit and absorption by Lyman alpha and other Lyman series lines, as well as probing ionised elements, such as C III, Si III and P VI.

GO 15141: The 6 pc DASH: A WFC3 1.6 micron Survey of the Orion Integral Shaped Filament


An image of the Orion Nebula superimposed on the 13CO map of Orion A (from this link ).
The Orion association is the largest nearby star-forming complex, providing a key laboratory for unlocking the secrets of star formation. As such, it has been subject to intense scrutiny at all wavelengths from both ground and space. Surveys at near-infrared and mid-infrared wavelenths, notably by Spitzer, have identified an extensive number of embedded sources, young stellar objects (YSOs) that are still accreting from the surrounding molecular gas. This proposal focuses on a 6 pc long filamentary structure in the Orion A molecular cloud, the complex that includes the Orion Nebula Cluster. this structrue sits behind the Orion Nebula at a distance of ~388 pc, and encompasses ~6000 solar masses of material. The WFC3-IR camera will be used to survey the filament for embedded stellar sources using the DASH technique, where the camera is stepped through a series of fields in a single orbit using gyro-control to define the pointings. Hubble's pointing accuracy is not as precise as under Fine Guidance Sensor control, but the multiple readouts obtained in the IR channel can be shifted to align the final composite frame. The increase in multiplexing will allow this prorgam to survey the full 6 pc x 0.9 pc structure.

Past weeks:
page by Neill Reid, updated 3/1/2018
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