Search Publications
Compressible Kelvin-Helmholtz instability in supermagnetosonic regimes
Le Contel, O.; Califano, F.; Pegoraro, F. +2 more
We investigate the transition from submagnetosonic to supermagnetosonic regimes in the presence of a sheared flow and density variations typically observed between the solar wind and the Earth's magnetosphere. In particular, we show the possibility of generating quasi-perpendicular magnetosonic shock structures under typical conditions that can be…
Suzaku Observation of the Unidentified Very High Energy Gamma-Ray Source HESS J1702-420
Dotani, Tadayasu; Bamba, Aya; Ozaki, Masanobu +6 more
A deep X-ray observation of the unidentified very high energy (VHE) gamma-ray source HESS J1702
The Abundance of Boron in Diffuse Interstellar Clouds
Lambert, D. L.; Federman, S. R.; Sheffer, Y. +1 more
We present a comprehensive survey of boron abundances in diffuse interstellar clouds from observations made with the Space Telescope Imaging Spectrograph (STIS) of the Hubble Space Telescope. Our sample of 56 Galactic sight lines is the result of a complete search of archival STIS data for the B II λ1362 resonance line, with each detection confirm…
A comprehensive approach to analyzing the XMM-Newton data of Seyfert 1 galaxies
Santos-Lleó, M.; Krongold, Y.; Rodríguez-Pascual, P. +3 more
Aims: We seek a comprehensive analysis of all the information provided by the XMM-Newton satellite of the four Seyfert 1 galaxies ESO 359-G19, HE 1143-1810, CTS A08.12, and Mrk 110, including the UV range, to characterize the different components that are emitting and absorbing radiation in the vicinity of the active nucleus.
Methods: Th…
The data mining III: An analysis of 21 eclipsing binary light-curves observed by the INTEGRAL/OMC
Zasche, P.
Twenty-one eclipsing binaries were selected for an analysis from a huge database of observations made by the INTEGRAL/OMC camera. The photometric data were processed and analyzed, resulting in a first light-curve study of these neglected eclipsing binaries. In several systems from this sample even their orbital periods have been confirmed or modif…
Simulating the Effects of Initial Pitch-angle Distributions on Solar Flares
Reeves, Katharine K.; Martens, Petrus; Winter, Henry D.
In this work, we model both the thermal and non-thermal components of solar flares. The model we use, HYLOOP, combines a hydrodynamic equation solver with a non-thermal particle tracking code to simulate the thermal and non-thermal dynamics and emission of solar flares. In order to test the effects of pitch-angle distribution on flare dynamics and…
Speed Distributions of Merging X-Ray Sources During Chromospheric Evaporation in Solar Flares
Ning, Zongjun
We explore the speed distributions of X-ray source motions after the start of chromospheric evaporation in two Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) flares. First, we make CLEAN images at 15 energy bands with a 12 second integration window; then, we outline a flaring loop geometry to cover the looptop and footpoint sources …
Regolith depth growth on an icy body orbiting Saturn and evolution of bidirectional reflectance due to surface composition changes
Esposito, Larry W.; Elliott, Joshua P.
Using a Markov chain model, we consider the regolith growth on a small body in orbit around Saturn, subject to meteoritic bombardment, and assuming all impact ejecta are re-collected. We calculate the growth of regolith and the fractional pollution, assuming an initial pure ice body and amorphous carbon as a pollutant. We extend the meteorite flux…
AGN Unification at z ~ 1: u - R Colors and Gradients in X-Ray AGN Hosts
Kocevski, Dale D.; Bouwens, Rychard J.; McGrath, Elizabeth J. +8 more
We present uncontaminated rest-frame u - R colors of 78 X-ray-selected active galactic nucleus (AGN) hosts at 0.5 < z < 1.5 in the Chandra Deep Fields measured with Hubble Space Telescope (HST)/Advanced Camera for Surveys/NICMOS and Very Large Telescope/ISAAC imaging. We also present spatially resolved NUV - R color gradients for a subsample…
X-ray and optical observations of the closest isolated radio pulsar
Tiengo, A.; de Luca, A.; Mereghetti, S. +3 more
With a parallactic distance of 170 pc, PSR J2144-3933 is the closest isolated radio pulsar currently known. It is also the slowest (P= 8.51 s) and least energetic (? erg s-1) radio pulsar; its radio emission is difficult to account for with standard pulsar models, since the position of PSR J2144-3933 in the period-period derivative diag…