Search Publications
First Determination of the True Mass of Coronal Mass Ejections: A Novel Approach to Using the Two STEREO Viewpoints
Vourlidas, Angelos; Colaninno, Robin C.
The twin Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) COR2 coronagraphs of the Solar Terrestrial Relations Observatory (STEREO) provide images of the solar corona from two viewpoints in the solar system. Since their launch in late 2006, the STEREO Ahead (A) and Behind (B) spacecraft have been slowly separating from Earth at…
The Hubble Sequence Beyond z = 2 for Massive Galaxies: Contrasting Large Star-forming and Compact Quiescent Galaxies
van Dokkum, Pieter G.; Franx, Marijn; Illingworth, Garth D. +2 more
We present Hubble Space Telescope NIC2 morphologies of a spectroscopic sample of massive galaxies at z ~ 2.3 by extending our sample of 9 compact quiescent galaxies (re ~ 0.9 kpc) with 10 massive emission-line galaxies. The emission-line galaxies are classified by the nature of their ionized emission; there are six star-forming galaxies…
HST/NICMOS Detection of HR 8799 b in 1998
Barman, Travis; Doyon, René; Marois, Christian +1 more
Three planets have been directly imaged around the young star HR 8799. The planets are 5-13 M Jup and orbit the star at projected separations of 24-68 AU. While the initial detection occurred in 2007, two of the planets were recovered in a reanalysis of data obtained in 2004. Here we present a detection of the furthest planet of that sy…
Subaru High-Resolution Spectroscopy of Star G in the Tycho Supernova Remnant
Schmidt, Brian P.; Asplund, M.; Nomoto, Ken'ichi +5 more
It is widely believed that Type Ia supernovae (SNe Ia) originate in binary systems where a white dwarf accretes material from a companion star until its mass approaches the Chandrasekhar mass and carbon is ignited in the white dwarf's core. This scenario predicts that the donor star should survive the supernova (SNe) explosion, providing an opport…
A Deep Hubble Space Telescope H-Band Imaging Survey of Massive Gas-Rich Mergers. II. The QUEST QSOs
Lutz, D.; Genzel, R.; Sturm, E. +11 more
We report the results from a deep Hubble Space Telescope (HST) NICMOS H-band imaging survey of 28 z < 0.3 QSOs from the Palomar-Green (PG) sample. This program is part of QUEST (Quasar/ULIRG Evolution Study) and complements a similar set of data on 26 highly nucleated ULIRGs presented in Paper I. Our analysis indicates that the fraction of QSOs…
An Analysis of the Shapes of Interstellar Extinction Curves. VI. The Near-IR Extinction Law
Fitzpatrick, E. L.; Massa, D.
We combine new observations from the Hubble Space Telescope's Advanced Camera of Survey with existing data to investigate the wavelength dependence of near-IR (NIR) extinction. Previous studies suggest a power law form for NIR extinction, with a "universal" value of the exponent, although some recent observations indicate that significant sight li…
Less Than 10 Percent of Star Formation in z ~ 0.6 Massive Galaxies is Triggered by Major Interactions
Papovich, Casey; Bell, Eric F.; Somerville, Rachel S. +26 more
Both observations and simulations show that major tidal interactions or mergers between gas-rich galaxies can lead to intense bursts of star formation. Yet, the average enhancement in star formation rate (SFR) in major mergers and the contribution of such events to the cosmic SFR are not well estimated. Here we use photometric redshifts, stellar m…
Variable Polarization Measured in the Prompt Emission of GRB 041219A Using IBIS on Board INTEGRAL
Götz, Diego; Laurent, Philippe; Lebrun, François +2 more
Polarization measurements provide a direct insight into the nature of astrophysical processes. Unfortunately, only a few instruments are available for this kind of measurement at γ-ray energies, and the sources need to be very bright. Gamma-ray bursts (GRBs) are ideal candidates due to their large flux over limited time intervals, maximizing the a…
The Detection of Inside-Out Disk Growth in M33
Dolphin, Andrew E.; Williams, Benjamin F.; Holtzman, Jon +2 more
We present resolved stellar photometry of four fields along the major axis of the M33 disk from images taken with the Advanced Camera for Surveys aboard the Hubble Space Telescope. The photometry provides a detailed census of the red clump in all fields and reaches the ancient main sequence in the outermost field. Through detailed modeling of the …
Globular Cluster Systems in Giant Ellipticals: The Mass/Metallicity Relation
Harris, William E.
Data from the Hubble Space Telescope taken with the Advanced Camera for Surveys/WFC camera have been used to investigate the globular cluster (GC) populations around six giant elliptical galaxies that are ~40 Mpc distant. From these six fields, imaged in B and I, a total of more than 15,000 candidate GCs have been measured, of which 8000 or more a…