Search Publications
High-resolution XMM-Newton Spectroscopy of the Cooling Flow Cluster A3112
Loewenstein, Michael; Smith, Randall K.; Mushotzky, Richard +4 more
We examine high signal-to-noise XMM-Newton European Photon Imaging Camera (EPIC) and Reflection Grating Spectrometer (RGS) observations to determine the physical characteristics of the gas in the cool core and outskirts of the nearby rich cluster A3112. The XMM-Newton Extended Source Analysis Software data reduction and background modeling methods…
Titan's Bulk Composition Constrained by Cassini-Huygens: Implication for Internal Outgassing
Hersant, F.; Tobie, G.; Gautier, D.
In the present report, by using a series of data gathered by the Cassini-Huygens mission, we constrain the bulk content of Titan's interior for various gas species (CH4, CO2, CO, NH3, H2S, Ar, Ne, Xe), and we show that most of the gas compounds (except H2S and Xe) initially incorporated within…
Spitzer and Herschel Multiwavelength Characterization of the Dust Content of Evolved H II Regions
Bernard, J. -P.; Natoli, P.; Paladini, R. +8 more
We have analyzed a uniform sample of 16 evolved H II regions located in a 2° × 2° Galactic field centered at (l,b) = (30°, 0°) and observed as part of the Herschel Hi-GAL survey. The evolutionary stage of these H II regions was established using ancillary radio-continuum data. By combining Hi-GAL PACS (70 µm, 160 µm) and SPIRE (250 &mi…
A Stellar Dynamical Mass Measurement of the Black Hole in NGC 3998 from Keck Adaptive Optics Observations
Barth, Aaron J.; Sarzi, Marc; van den Bosch, Remco C. E. +1 more
We present a new stellar dynamical mass measurement of the black hole in the nearby, S0 galaxy NGC 3998. By combining laser guide star adaptive optics observations obtained with the OH-Suppressing Infrared Imaging Spectrograph on the Keck II telescope with long-slit spectroscopy from the Hubble Space Telescope and the Keck I telescope, we map out …
Herschel PACS and SPIRE Observations of Blazar PKS 1510-089: A Case for Two Blazar Zones
Szczerba, Ryszard; Nalewajko, Krzysztof; Madejski, Greg M. +5 more
We present the results of observations of blazar PKS 1510-089 with the Herschel Space Observatory PACS and SPIRE instruments, together with multiwavelength data from Fermi/LAT, Swift, SMARTS, and Submillimeter Array. The source was found in a quiet state, and its far-infrared spectrum is consistent with a power law with a spectral index of α ~= 0.…
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…