Search Publications
Discovery of a broad iron line in the black hole candidate Swift J1753.5-0127, and the disc emission in the low/hard state revisited
Mostafa, Reham; Hiemstra, Beike; Soleri, Paolo +3 more
We analysed simultaneous archival XMM-Newton and Rossi X-ray Timing Explorer observations of the X-ray binary and black hole candidate Swift J1753.5-0127. In a previous analysis of the same data, a soft thermal component was found in the X-ray spectrum, and the presence of an accretion disc extending close to the innermost stable circular orbit wa…
Hydrogen Lyman-α and Lyman-β spectral radiance profiles in the quiet Sun
Marsch, E.; Curdt, W.; Tian, H. +1 more
Aims: We extend earlier work by studying the line profiles of the hydrogen Lyman-α and Lyman-β lines in the quiet Sun. They were obtained quasi-simultaneously in a raster scan with a size of about 150'' × 120'' near disk center.
Methods: The self-reversal depths of the Ly-α and Ly-β profiles. we are quantified by measuring the maximum spectral…
Ionization processes in the atmosphere of Titan. II. Electron precipitation along magnetic field lines
Gronoff, G.; Lilensten, J.; Modolo, R.
Context: The Cassini probe regularly passes the vicinity of Titan, providing new insights into particle precipitation by use of its electron and ion spectrometers. A discrepancy between precipitation models and observations of electron fluxes has been found. This discrepancy was suspected to be caused by the geometry of the magnetic field.
Aim…
PHL 1092 as a transient extreme X-ray weak quasar
Brandt, W. N.; Fabian, A. C.; Boller, Th. +2 more
We report a dramatic variability event in the X-ray history of the narrow-line quasar PHL 1092 (z = 0.396). Our latest 2008 XMM-Newton observation reveals a flux drop of ~200 with respect to the previous observation performed about 4.5 yr earlier, and a drop of ~135 with respect to its historical flux. Despite the huge X-ray variation, the UV flux…
A comparison of the formation and evolution of magnetic flux ropes in solar coronal mass ejections and magnetotail plasmoids
Moldwin, M. B.; Linton, M. G.
Solar coronal mass ejections and their interplanetary counterparts often show evidence of a twisted flux rope structure that is nearly identical, though of vastly different spatial scale, to plasmoids observed in the Earth's magnetotail. This paper reviews the current understanding of flux rope formation, morphology, and evolution in coronal mass …
On the Nonrelativistic Origin of Red-skewed Iron Lines in Cataclysmic Variable, Neutron Star, and Black Hole Sources
Laurent, Philippe; Titarchuk, Lev; Shaposhnikov, Nikolai
We perform the analysis of the iron Kα lines detected in three sources representing three types of accreting compact sources: cataclysmic variable (CV) GK Per, neutron star (NS) Serpens X-1, and black hole (BH) GX 339-4. We find, using data from Epic-PN Camera onboard XMM-Newton observatory, that the iron Kα emission line in …
Redshift Evolution in the Iron Abundance of the Intracluster Medium
Bregman, Joel N.; Anderson, Michael E.; Mullis, C. R. +1 more
Clusters of galaxies provide a closed box within which one can determine the chemical evolution of the gaseous baryons with cosmic time. We studied this metallicity evolution in the hot X-ray emitting baryons through an analysis of XMM-Newton observations of 29 galaxy clusters in the redshift range, 0.3 < z < 1.3. Taken alone, this data set …
Surface elements and landing strategies for small bodies missions - Philae and beyond
Ulamec, Stephan; Biele, Jens
The investigation of small bodies, comets and asteroids, can contribute substantially to our understanding of the formation and history of the Solar System. In-situ observations by Landers play a prominent role in this field. The Rosetta Lander - Philae - is currently on its way to comet 67P/Churyumov-Gerasimenko. It will land in November 2014 and…
Integral field optical spectroscopy of a representative sample of ULIRGs. I. The data
Colina, L.; Monreal-Ibero, A.; Arribas, S. +1 more
Context: Ultraluminous infrared galaxies (ULIRGs) are among the brightest objects in the local Universe. They are powered by strong star formation and/or an AGN. As a result of the merger process, they are also likely to be the progenitors of elliptical galaxies. The study of the structure and kinematics of samples of local ULIRGs is necessary to …
The first cyclotron harmonic of 4U 1538-52
Torrejón, J. M.; Camero-Arranz, A.; Kreykenbohm, I. +3 more
Context: Cyclotron resonant scattering features are an essential tool for studying the magnetic field of neutron stars. The fundamental line provides a measure of the field strength, while the harmonic lines provide information about the structure and configuration of the magnetic field. Until now only a handful of sources are known to display mor…