HST this week: 135



This week on HST


HST Programs: May 14 - May 21, 2017

Program Number Principal Investigator Program Title
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
14114 Pieter van Dokkum, Yale University A Wide-Field WFC3 Imaging Survey in the COSMOS Field
14181 S Thomas Megeath, University of Toledo A Snapshot WFC3 IR Survey of Spitzer/Hershel-Identified Protostars in Nearby Molecular Clouds
14212 Karl Stapelfeldt, Jet Propulsion Laboratory A Snapshot Imaging Survey of Spitzer-selected Young Stellar Objects in Nearby Star Formation Regions*.t23
14241 Daniel Apai, University of Arizona Cloud Atlas: Vertical Cloud Structure and Gravity in Exoplanet and Brown Dwarf Atmospheres
14251 Amy E. Reines, National Optical Astronomy Observatory, AURA The Structures of Dwarf Galaxies Hosting Massive Black Holes
14594 Rich Bielby, Durham Univ. QSAGE: QSO Sightline And Galaxy Evolution
14606 Brooke Devlin Simmons, University of California - San Diego Secular Black Hole Growth and Feedback in Merger-Free Galaxies
14611 Or Graur, Harvard University Going gently into the night: constraining Type Ia supernova nucleosynthesis using late-time photometry
14612 Erich Karkoschka, University of Arizona Titan at Opposite Seasons Using STIS Image Cubes
14616 Simon Porter, Southwest Research Institute Primordial Triplicity: A Census of Hierarchical Triples in the Cold Classical Kuiper Belt
14618 Michael Shara, American Museum of Natural History Ultraviolet Flashers in M87: Rapidly Recurring Novae as SNIa Progenitors
14633 Kevin France, University of Colorado at Boulder A SNAP UV Spectroscopic Study of Star-Planet Interactions
14634 Denis C Grodent, Universite de Liege HST-Juno synergistic approach of Jupiter's magnetosphere and ultraviolet auroras
14636 Igor Dmitrievich Karachentsev, Russian Academy of Sciences, Special Astrophysical Obs. TRGB Distances to the Edge Between the Local Sheet and Virgo Infall: Last of the Low Hanging Fruit
14644 Pieter van Dokkum, Yale University Exploring the extremely low surface brightness sky: distances to 23 newly discovered objects in Dragonfly fields
14661 Michael H. Wong, University of California - Berkeley Wide Field Coverage for Juno (WFCJ): Jupiter's 2D Wind Field and Cloud Structure
14666 Stefano Casertano, Space Telescope Science Institute Astrometric Light Deflection Test of General Relativity for Non-spherical Bodies: Close Approach to Jupiter
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
14681 Alessandra Aloisi, Space Telescope Science Institute Tracing Galactic Outflows to the Source: Spatially Resolved Feedback in M83 with COS
14694 Stephan Robert McCandliss, The Johns Hopkins University SDSSCGB-46589.1 -- a Lyman Alpha Blob at Low Redshift?
14699 David Sobral, Lancaster University The hosts of the early ionized bubbles: the nature and diversity of the most luminous Lyman-alpha emitters at z~6-7
14717 Iair Arcavi, University of California - Santa Barbara What is Enhancing the Tidal Disruption Rate of Stars in Post-Starburst Galaxies?
14734 Nitya Kallivayalil, The University of Virginia Milky Way Cosmology: Laying the Foundation for Full 6-D Dynamical Mapping of the Nearby Universe
14738 Arunav Kundu, Eureka Scientific Inc. A Far Ultraviolet Study of Globular Clusters in NGC 3115
14762 Justyn Robert Maund, University of Sheffield A UV census of the sites of core-collapse supernovae
14767 David Kent Sing, University of Exeter The Panchromatic Comparative Exoplanetary Treasury Program
14806 Goeran Oestlin, Stockholm University SAFE: Star clusters, lyman Alpha and Feedback in Eso338-04
14810 John A. Biretta, Eureka Scientific Inc. High-Precision Proper Motions in the M87 Jet
14840 Andrea Bellini, Space Telescope Science Institute Schedule Gap Pilot
14892 Bruce McCollum, American University Determining the Progenitor of a Red Transient
14922 Patrick Kelly, University of California - Berkeley Probing the Nature of Dark Matter with Individual Stars Highly Magnified by a Galaxy Cluster
14923 Goeran Oestlin, Stockholm University LYCAT - LYman Continuum and Alpha in Tol1214-277
14928 Keith S. Noll, NASA Goddard Space Flight Center Orbit of the Patroclus-Menoetius Binary, a Lucy Mission Target

Selected highlights

GO 14633: A SNAP UV Spectroscopic Study of Star-Planet Interactions


SOHO image of an extremely strong solar flare
Stellar activity, whether through flares and coronal mass ejections, has the potential to affect the ability of life to evolve and survive on otherwise habitable planets in stellar systems. High energy radiation can lead to significant mutations, and particle ejections can actually strip the atmospheres of unfortunate planets. Previous HST programs have focused on low mass M dwarfs, the most populous stars in the galaxy, and systems where the habitable zone lies close to the parent star, with a correspondingly higher vulnerability. Those observations suggest evidence for interactions between the stellar transition region and the planets, with a correlation between the presence of high temperature emission lines (N V, C IV, Si IV) and the planetary mass and orbit i.e. suggestive of planetary interactions driving conditions in the stellar corona. The present SNAP program expand obsevations to higher-mass K dwarfs and solar-type G dwarfs that are known to harbour exoplanets, searching for similar correlations. The Cosmic Origins Spectrograph will be used to obtain UV spectra (1150-1450 Angstroms), providing a broad sampling of the range of activity levels among these dwarfs.

GO 14636 :TRGB Distances to the Edge Between the Local Sheet and Virgo Infall: Last of the Low Hanging Fruit


The galaxies within the Local Group
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. Moving beyond the Local Group, we encounter five further galaxy groups within ~3 Mpc: the M81 group, the Canes I group, the Maffei group, the Sculptor group and the NGC 5128 group ( see this link ). Beyond them lies the Virgo supercluster. HST is well suited to mapping the distance distribution of the inner groups: the high sensitivity of the Advanced Camera for Surveys and Wide-Field Camera 3 combined with the unparalleled angular resolution enables resolution of the most luminous stars; constructing the colour-magnitude provides access to a number of distance indicators, including the tip of the first red giant branch (RGB). Red giants have completed the core hydrogen-burning main-sequence stage of evolution and have moved to burning hydrogen in an inner shell. The maximum luminosity in this phase, and hence the location of the tip of the RGB, is set when the core reaches a sufficiently high temperature to ignite helium burning, the so-called helium flash. At that point, hydrogen shell-burning is extinguished, the star contracts and moves onto the horizontal branch. The present program focuses on 20 galaxies lying ion the so-called "Local Sheet" in the foreground of the Virgo cluster. These systems have expected distances of 6-8 Mpc., lying at the extremes of the current capabilities of the TPRG method with Hubble.

GO 14661: Wide Field Coverage for Juno (WFCJ): Jupiter's 2D Wind Field and Cloud Structure


Global map of Jupiter from OPAL's 2015 observations
The gas giants and ice giants in the outer system have extended, dynamic gaseous atmospheres that show a range of phenomena reflecting the underlying composition and cloud structure. These are generally driven by solar insolation, with the consequence that the frequency, scale and range of features diminishes from Jupiter through saturn and Uranus to Neptune. Monitoring the changes in the wide variety of features in these atmospheres can provide insight into the velocity structure and the energy sources.Hubble has been monitoring Jupiter, Uranus and Neptune over the last 2 years as part of the Outer Planets Atmospheric Legacy (OPAL) prorgam. Jupiter is receiving poarticular attention this year following the arrival of the Juno probe in 2016. NASA launched the JUpiter Near-polar Orbiter in 2011, and it will provide the first in situ measurements of Jupiter's magnetic field and polar magnetosphere since the Galileo satellite which actively monitored Jupiter from 1995 to 2003. Juno arrived at Jupiter on July 4th 2016 and entered a 53-day orbit. The present program is designed to support in situ measurements made with the IR imager/spectrometer and the Microwave Radiometer. The program targets Jupiter with a wide range of broad and narrow-band filters on Wide Field Camera 3.

GO 14922: Probing the Nature of Dark Matter with Individual Stars Highly Magnified by a Galaxy Cluster


Finding chart for the multiply imaged supernova, SN Refsdal, discovered in November 2014 in cluster MACJ1149
Throughout Cycles 21, 22 and 23, Hubble conducted deep imaging observations of six galaxy clusters as the Frontier Fields Director's Time program. Those observations have provided a basis for several synergistic programs. In particular, the observations enabled a search for supernovae at high redshifts, z> 1.5, aiming to set further constraints on dark energy and probing the frequency of supernovae as a function of redshift, the delay time and hence the likely progenitors.
In 2014, observations of the fourth cluster, MACSJ1149.5+2223, resulted in the detection of a particularly unusual object - multiple lensed images of a supernova in a redshift z=1.49 galaxy that is itself multiply lensed. Each of those images results from light following a different path due to the gravitational potential of the foreground cluster and galaxies. Dubbed Supernova Refsdahl, after the gravitational lensing pioneer, the original detections were followed over the course of their fading. But, more spectacularly, models of the cluster potential and the consequent light paths led to a prediction that the supernova should appear in one of the other lensed images of the parent galaxy in late 2015. The supernova was not present in observations obtained on November 14, 2015, but was detected in the December 11 observations, thus representing the first time that a supernova has been "predicted" successfully.Further observations are being obtained to monitor the light curve.
Subsequent observations have revealed a new variable object within the cluster, approximately 5 arcsec from Refsdahl. Dubbed "Icarus", models strongly suggest that the source originates from a single early-type star at edshift z~1.49 that is crossing a gravitational caustic, leading to an brightness amplfication of somehwere between 105 and 106. Subsequent observations, tracking the brightness evolution of Icarus, have revealed two new sources - "Chucky" and "Perdix". This behaviour may be providing insight on the nature of dark amtter, perhaps pointing to a granular structure that can produce successive microlensing events from a background star cluster. The present program will continue observations of MACS 1149 to track these events and monitor for new occurences.

Past weeks:
page by Neill Reid, updated 2 /1/2017
These pages are produced and updated on a best effort basis. Consequently, there may be periods when significant lags develop. we apologise in advance for any inconvenience to the reader.

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