Search Publications
The Chemical Properties of Low-redshift QSOs
Nagao, Tohru; Kim, Sang Chul; Woo, Jong-Hak +1 more
We investigate the chemical properties of low-z QSOs, using archival UV spectra obtained with the Hubble Space Telescope and International Ultraviolet Explorer for a sample of 70 Palomar-Green QSOs at z < 0.5. By utilizing the flux ratios of UV emission lines (i.e., N V/C IV, (Si IV+O IV])/C IV, and N V/He II) as metallicity indicators, we comp…
CoRoT 102918586: a γ Doradus pulsator in a short-period eccentric eclipsing binary
Gandolfi, D.; Rainer, M.; Montalbán, J. +2 more
Pulsating stars in eclipsing binary systems are powerful tools to test stellar models. Binarity enables us to constrain the pulsating component's physical parameters and this knowledge drastically improves the input physics for asteroseismic studies. The study of stellar oscillations then allows us to improve our understanding of stellar interiors…
The Surprising Absence of Absorption in the Far-ultraviolet Spectrum of Mrk 231
Lutz, D.; Genzel, R.; Maiolino, R. +11 more
Mrk 231, the nearest (z = 0.0422) quasar, hosts both a galactic-scale wind and a nuclear-scale iron low-ionization broad absorption line (FeLoBAL) outflow. We recently obtained a far-ultraviolet (FUV) spectrum of this object covering ~1150-1470 Å with the Cosmic Origins Spectrograph on board the Hubble Space Telescope. This spectrum is highly pecu…
Wind driven capillary-gravity waves on Titan's lakes: Hard to detect or non-existent?
Lorenz, R. D.; Lunine, J. I.; Hayes, A. G. +13 more
Saturn's moon Titan has lakes and seas of liquid hydrocarbon and a dense atmosphere, an environment conducive to generating wind waves. Cassini observations thus far, however, show no indication of waves. We apply models for wind wave generation and detection to the Titan environment. Results suggest wind speed thresholds at a reference altitude o…
Galaxy Interactions in Compact Groups. I. The Galactic Winds of HCG16
Kewley, Lisa J.; Dopita, Michael A.; Vogt, Frédéric P. A.
Using the WiFeS integral field spectrograph, we have undertaken a series of observations of star-forming galaxies in compact groups. In this first paper dedicated to the project, we present the analysis of the spiral galaxy NGC 838, a member of the Hickson Compact Group 16, and of its galactic wind. Our observations reveal that the wind forms an a…
Magnetic Structure Producing X- and M-class Solar Flares in Solar Active Region 11158
Choe, G. S.; Shiota, D.; Inoue, S. +2 more
We study the three-dimensional magnetic structure of the solar active region 11158, which produced one X-class and several M-class flares on 2011 February 13-16. We focus on the magnetic twist in four flare events, M6.6, X2.2, M1.0, and M1.1. The magnetic twist is estimated from the nonlinear force-free field extrapolated from the vector fields ob…
Gypsum, opal, and fluvial channels within a trough of Noctis Labyrinthus, Mars: Implications for aqueous activity during the Late Hesperian to Amazonian
Weitz, Catherine M.; Grant, John A.; Bishop, Janice L.
We investigate in detail the morphology, mineralogy, and stratigraphy of light-toned deposits within one trough of Noctis Labyrinthus, centered at -6.8°N, 261.1°E. CRISM spectra taken from light-toned layered deposits in the northern portion of the trough exhibit absorptions around 1.41, 1.92 and 2.21 µm, consistent with mixtures of opal and…
The Recurrent Nova T Pyx: Distance and Remnant Geometry from Light Echoes
Sokoloski, J. L.; Crotts, Arlin P. S.; Lawrence, Stephen +1 more
The recurrent nova T Pyxidis (T Pyx) is well known for its small binary separation, its unusually high luminosity in quiescence, and the spectacular Hubble Space Telescope (HST) images of its surrounding remnant. In 2011 April, T Pyx erupted for the first time since 1966. Here we describe HST observations in late 2011 of a transient reflection neb…
Deuterated water in the solar-type protostars NGC 1333 IRAS 4A and IRAS 4B
Codella, C.; Ceccarelli, C.; van Dishoeck, E. F. +19 more
Context. The measure of the water deuterium fractionation is a relevant tool for understanding mechanisms of water formation and evolution from the prestellar phase to the formation of planets and comets.
Aims: The aim of this paper is to study deuterated water in the solar-type protostars NGC 1333 IRAS 4A and IRAS 4B, to compare their HDO ab…
Herschel Observations of the W3 GMC: Clues to the Formation of Clusters of High-mass Stars
Martin, P. G.; Hill, T.; White, G. J. +22 more
The W3 GMC is a prime target for the study of the early stages of high-mass star formation. We have used Herschel data from the HOBYS key program to produce and analyze column density and temperature maps. Two preliminary catalogs were produced by extracting sources from the column density map and from Herschel maps convolved to 500 µm resol…