This week on HST


HST Programs: January 29 - February 4 2018

Program Number Principal Investigator Program Title
14607 Eleonora Troja, University of Maryland Identify the signature of neutron star mergers through rapid Hubble observations of a short GRB
14624 Hector G. Arce, Yale University Taming the Flame: A Near-IR imaging study of the NGC 2024 (Flame Nebula) cluster
14634 Denis C Grodent, Universite de Liege HST-Juno synergistic approach of Jupiter's magnetosphere and ultraviolet auroras
14662 Luigi R. Bedin, Osservatorio Astronomico di Padova The end of the White Dwarf Cooling Sequences of Omega Centauri
14697 Bradley M Peterson, The Ohio State University A Cepheid Distance to NGC 4051
14728 John S. Gallagher, University of Wisconsin - Madison Hearts of Darkness: Compact Obscured Nuclei in S0/a Galaxies
14772 Bart P. Wakker, University of Wisconsin - Madison Observing gas in Cosmic Web filaments to constrain simulations of cosmic structure formation
14840 Andrea Bellini, Space Telescope Science Institute Schedule Gap Pilot
14849 Eric S. Perlman, Florida Institute of Technology The 3C111 Jet: X-ray Variability, Spectrum & Broadband SED
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?
15077 Tucker Jones, University of California - Davis Accurate Emission Line Diagnostics at High Redshift
15081 Andrew Robinson, Rochester Institute of Technology Revealing the circum-nuclear torus: HST imaging of active galaxies observed during a Spitzer reverberation mapping campaign
15113 Abhijit Saha, National Optical Astronomy Observatory, AURA Extending the DA white dwarf spectrophotometric network to the Southern Hemisphere
15115 John David Silverman, University of Tokyo Emergence of the supermassive black hole - galaxy mass relations at z > 1
15133 Peter Erwin, Max-Planck-Institut fur extraterrestrische Physik Solving the Mystery of Galaxy Bulges and Bulge Substructure
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
15162 Peter Blanchard, Harvard University Constraining the Late-Time Light Curve Behavior of Three Diverse Superluminous Supernovae
15171 Bryan Jason Holler, Space Telescope Science Institute The rotation period, orbit, and mass of Eris' satellite Dysnomia
15179 Ruth C. Peterson, SETI Institute Astrophysics Meets Atomic Physics: Fe I Line Identifications and Templates for Old Stellar Populations from Warm and Hot Stellar UV Spectra
15181 David J. V. Rosario, Durham Univ. AGN Before and After: Towards a balanced view of the connection between circumnuclear gas and nuclear black hole activity
15189 David John Wilson, The University of Warwick Post Common Envelope Binaries as probes of M dwarf stellar wind and habitable zone radiation environments
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
15238 Adam L. Kraus, University of Texas at Austin The IMF to Planetary Masses Across the Milky Way
15241 Kirsten L. Larson, California Institute of Technology Clumpy Star Formation in Local LIRGS
15242 Lucia Marchetti, Open University SNAPshot observations of the largest sample of lensed candidates in the Equatorial and Southern Sky identified with Herschel
15265 John Blakeslee, NRC Herzberg Institute of Astrophysics MASSIVE+: The Growth Histories of MASSIVE Survey Galaxies from their Globular Cluster Colors
15275 Karoline Gilbert, Space Telescope Science Institute Securing HST's UV Legacy in the Local Volume: Probing Star Formation and the Interstellar Medium in Low Mass Galaxies
15303 Chris D'Andrea, University of Pennsylvania Revealing the Environmental Dependence in Superluminous Supernovae Diversity
15328 Jessica Agarwal, Max Planck Institute for Solar System Research Orbital period and formation process of the exceptional binary asteroid system 288P
15344 David Jewitt, University of California - Los Angeles Centaurs and Activity Beyond the Water Sublimation Zone
15350 Walter Peter Maksym, Smithsonian Institution Astrophysical Observatory Resolved BPT Mapping of Nearby AGN
15424 William B. Sparks, Space Telescope Science Institute An intensive ultraviolet imaging campaign for Europa's plumes
15427 James M. Schombert, University of Oregon Exploring the Nature of Dark Matter Through Near-IR CMD's of LSB Galaxies

Selected highlights

GO 14662: The end of the White Dwarf Cooling Sequences of Omega Centauri


ACS imaging of the central regions of Omega Cen
Globular clusters are members of the Galactic halo population, which formed during the first extensive period of star formation in the Milky Way. As such, the properties of the 106 to 107 stellar constituents can provide crucial insight into the earliest stages of galaxy formation. Hubble has conducted a significant number of observing programs targeting these systems, with the majority designed to obtain moderately deep, multicolour imaging data of a range of clusters. Those programs probe evolved stars, on the red giant and horizontal branch, and generally extend only a few magnitudes below the main-sequence turnoff. Noetheless, the exqusite photometric precision offered by HST's camera has revealed that the majority of these systems have multiple stellar populations, rather than conforming to traditional single-burst formation models. A few clusters have been studied in detail - specifically, the two nearest clusters, NGC 6397, an extremely metal-poor cluster, and M4, a moderately metal-rich systems; Omega Centauri, one of the most massive clusters, perhaps even the remnant core of a dwarf galaxy; and 47 Tucanae, one of the higher metallicity systems, lying in the foreground of the Small Magellanic Cloud. Deep imaging of all four clusters has succeeded in clear detecion of the white dwarf cooling sequence in those clusters, and those data have been used to derive age estimates. The present program builds on past observations in aiming to probe the multiple white dwarf cooling sequences in Omega Cen. The WFC3/UVIS and ACS/WFC cameras will be used to obtain multi-colour imaging of the cluster. Those observations should enable measurement over the full extent of the white dwarf cooling sequences, offering the potential of resolving the nature and origin(s) of the distinct stellar populations.

GO 15171: The rotation period, orbit, and mass of Eris' satellite Dysnomia


Hubble Space Telescope images of Eris and Dysnomia
As is now well known, on 2006 the IAU changed pluto's status from the outermost planet in the solar system to a dwarf planet, and the largest currently-known member of the Kuiper. One of the main factors in adopting that revised classification was the discovery of several other large KBOs, at least comparable in size with Pluto. Those systems included Eris, discovered in 2005 by Mike Brown using the Palomar Schmidt telescope. Eris is probably slightly smaller than Pluto, with a diameter of ~2300 miles. Deep imaging with the Keck adaptive optics revealed that Eris has a companion, the moon Dysnomia. The system has since been imaged with Hubble, and the initial orbital measurements suggest that Eris is more massive (i.e. denser) than Pluto. The present program will use the Wide Fields camera 3 UVIS channel to monitor the system, providing both an improved determination of the relative orbits of the pair and potential measurment of the rotational period of Dysnomia through tracking photometric variations.

GO 15275: Securing HST's UV Legacy in the Local Volume: Probing Star Formation and the Interstellar Medium in Low Mass Galaxies


Subaru image of the Leo A dwarf galaxy, one of the galaxies targeted in this program
The Milky Way Galaxy is a member of a relatively sparse set of galaxies known as the Local Group. Fifty-four members are currently catalogued within ~1.5 Mpc., with the overwhelming majority being dwarf systems. The Milky Way and M31 are the two dominant members, with M33 the only other spiral system. Most of the dwarf galaxies are satellites of the three major systems, typically dwarf spheroidal systems that have exhausted most of their gaseous content and exhibit little or no current star formation. However, there are also a number of irregular dwarfs that are gas rich and exhibit ongoing star formation. Hubble is ideally suited to probing the characteristics of those systems, providing both unparalleled angular resolution to resolve the stellar populations and UV sensitivity to highlight actvie star formation regions. The present program is using Wide Field Camera 3 to obtain ultraviolet imaging of 22 low-mass, nearby (<3.5 Mpc) galaxies towards the edge of the Local Group. Combined with previous optical and near-IR imaging, the data will probe the star formation history in these systems, measure the UV flux, and map the dust distributions and composition.

GO 15242: SNAPshot observations of the largest sample of lensed candidates in the Equatorial and Southern Sky identified with Herschel


An ALMA/HST composite image of the lensed galaxy, SDP 81
Gravitational lensing is a consequence the theory of general relativity. Its importance as an astrophysical tool first became apparent with the realisation (in 1979) that the quasar pair Q0957+561 actually comprised two lensed images of the same background quasar. In the succeeding years, lensing has been used primarily to probe the mass distribution of galaxy clusters, using theoretical models to analyse the arcs and arclets that are produced by strong lensing of background galaxies, and the large-scale mass distribution, through analysis of weak lensing effects on galaxy morphologies. Gravitational lensing can also be used to investigate the mass distribution of individual galaxies. Until recently, the most common background sources that were being detected and investigates were quasars. Galaxy-galaxy lenses, however, offer a distinct advantage, since the background source is extended, and therefore imposes a stronger constraints on the mass distribution of the lensing galaxy than a point-source QSO. HST has carried out a number of programs following up candidate lenses identified from the Sloan Digital Sky Survey and based on sub-mm observation by the Herschel satellite. The present program aims to build on the latter sample by using Hubble Snapshot imaging with the F110W filter in the WFC3-IR camera to verify the nature of up to 200 lensing candidates from the major herschel extragalactic surveys.

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