Search Publications
The 12C/13C Ratio on Titan from Cassini INMS Measurements and Implications for the Evolution of Methane
Nixon, Conor A.; Mousis, Olivier; Lunine, Jonathan I. +6 more
We have re-evaluated the Cassini Ion Neutral Mass Spectrometer (INMS) 12C/13C ratios in the upper atmosphere of Titan based on new calibration sensitivities and an improved model for the NH3 background in the 13CH4 mass channel. The INMS measurements extrapolated to the surface give a 12<…
X-Ray Emission from an Asymmetric Blast Wave and a Massive White Dwarf in the Gamma-Ray Emitting Nova V407 Cyg
Chomiuk, Laura; Mukai, Koji; Donato, Davide +2 more
Classical nova events in symbiotic stars, although rare, offer a unique opportunity to probe the interaction between ejecta and a dense environment in stellar explosions. In this work, we use X-ray data obtained with Swift and Suzaku during the recent classical nova outburst in V407 Cyg to explore such an interaction. We find evidence of both equi…
Radio Imaging of Shock-accelerated Electrons Associated with an Erupting Plasmoid on 2010 November 3
Krucker, Säm; Lin, R. P.; Bain, H. M. +1 more
We present observations of a metric type II solar radio burst that occurred on the 3rd of November 2010 in association with an erupting plasmoid. The eruption was well observed by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory and the Reuven Ramaty High Energy Solar Spectroscopic Imager, while the burst occurred in …
On the Doppler Velocity of Emission Line Profiles Formed in the "Coronal Contraflow" that Is the Chromosphere-Corona Mass Cycle
De Pontieu, Bart; McIntosh, Scott W.; Tian, Hui +1 more
This analysis begins to explore the complex chromosphere-corona mass cycle using a blend of imaging and spectroscopic diagnostics. Single Gaussian fits (SGFs) to hot emission line profiles (formed above 1 MK) at the base of coronal loop structures indicate material blueshifts of 5-10 km s-1, while cool emission line profiles (formed bel…
Transmission Spectroscopy of Exoplanet XO-2b Observed with Hubble Space Telescope NICMOS
Crouzet, N.; Burke, C.; Long, D. +1 more
Spectroscopy during planetary transits is a powerful tool to probe exoplanet atmospheres. We present the near-infrared transit spectroscopy of XO-2b obtained with Hubble Space Telescope NICMOS. Uniquely for NICMOS transit spectroscopy, a companion star of similar properties to XO-2 is present in the field of view. We derive improved star and plane…
High-resolution Reddening Map in the Direction of the Stellar System Terzan 5
Dalessandro, Emanuele; Mucciarelli, Alessio; Ferraro, Francesco R. +7 more
We have used optical images acquired with the Hubble Space Telescope to construct the first high-resolution extinction map in the direction of Terzan 5, a peculiar stellar system in the inner bulge of our Galaxy. The map has a spatial resolution of 8'' × 8'', over a total field of view of 200'' × 200''. The absorption clouds show a patchy structur…
On the Weak-wind Problem in Massive Stars: X-Ray Spectra Reveal a Massive Hot Wind in µ Columbae
Hamaguchi, Kenji; Huenemoerder, David P.; Ignace, Richard +4 more
µ Columbae is a prototypical weak-wind O star for which we have obtained a high-resolution X-ray spectrum with the Chandra LETG/ACIS instrument and a low-resolution spectrum with Suzaku. This allows us, for the first time, to investigate the role of X-rays on the wind structure in a bona fide weak-wind system and to determine whether there a…
The Size Evolution of Passive Galaxies: Observations from the Wide-Field Camera 3 Early Release Science Program
Holtzman, J. A.; O'Connell, R. W.; Walker, A. R. +28 more
We present the size evolution of passively evolving galaxies at z ~ 2 identified in Wide-Field Camera 3 imaging from the Early Release Science program. Our sample was constructed using an analog to the passive BzK galaxy selection criterion, which isolates galaxies with little or no ongoing star formation at z >~ 1.5. We identify 30 galaxies in…
Herschel Observations of Interstellar Chloronium
Menten, Karl M.; Nagy, Zsófia; Neufeld, David A. +21 more
Using the Herschel Space Observatory's Heterodyne Instrument for the Far-Infrared, we have observed para-chloronium (H2Cl+) toward six sources in the Galaxy. We detected interstellar chloronium absorption in foreground molecular clouds along the sight lines to the bright submillimeter continuum sources Sgr A (+50 km s-1<…
Broadband Spectroscopy Using Two Suzaku Observations of the HMXB GX 301-2
Rothschild, Richard E.; Fürst, Felix; Pottschmidt, Katja +5 more
We present the analysis of two Suzaku observations of GX 301-2 at two orbital phases after the periastron passage. Variations in the column density of the line-of-sight absorber are observed, consistent with accretion from a clumpy wind. In addition to a cyclotron resonance scattering feature (CRSF), multiple fluorescence emission lines were detec…