Search Publications

Active galaxy 4U 1344-60: did the relativistic line disappear?

Bianchi, S.; Guainazzi, M.; Piconcelli, E. +4 more

Context. X-ray bright active galactic nuclei represent a unique astrophysical laboratory for studying accretion physics around super-massive black holes.
Aims: 4U 1344-60 is a bright Seyfert galaxy which revealed relativistic reflection features in the archival XMM-Newton observation.
Methods: We present the spectroscopic results of new …

The Swift BAT Survey Detects Two Optical Broad Line, X-Ray Heavily Obscured Active Galaxies: NVSS 193013+341047 and IRAS 05218-1212

Reynolds, Christopher S.; Mushotzky, Richard F.; Winter, Lisa M. +2 more

The Swift Burst Alert Telescope (BAT) is discovering interesting new objects while monitoring the sky in the 14-195 keV band. Here we present the X-ray properties and spectral energy distributions (SEDs) for two unusual active galactic nucleus sources. Both NVSS 193013+341047 and IRAS 05218-1212 are absorbed, Compton-thin, but heavily obscured (N …

Tracing colliding winds in the ultraviolet line orbital variability of gamma-ray binaries

McSwain, M. Virginia; Dubus, Guillaume; Szostek, Anna

Gamma-ray binaries emit most of their radiated power beyond ∼10 MeV. The non-thermal emission is thought to arise from the interaction of the relativistic wind of a rotation-powered pulsar with the stellar wind of its massive (O or Be) companion star. A powerful pulsar creates an extended cavity, filled with relativistic electrons, in the radiativ…

Sub-arcsecond radio and optical observations of the likely counterpart to the gamma-ray source 2FGL J2056.7+4939

Luque-Escamilla, P. L.; Martí, J.; Muñoz-Arjonilla, A. J. +1 more

We have searched and reviewed all multi-wavelength data available for the region towards the gamma-ray source 2FGL J2056.7+4939 in order to constrain its possible counterpart at lower energies. As a result, only a point-like optical/infrared source with flat-spectrum radio emission is found to be consistent with all X-ray and gamma-ray error circl…

XMM-Newton confirmation of a new intermediate polar: XMMU J185330.7-012815

Hui, C. Y.; Sriram, K.; Choi, C. -S.

We report on the results of a detailed spectro-imaging and temporal analysis of an archival XMM-Newton observation of a new intermediate polar XMMU J185330.7-012815. Its X-ray spectrum can be well described by a multitemperature thermal plasma model with the K lines of heavy elements clearly detected. Possible counterparts of XMMU J185330.7-012815…

Titan through time: Formation, evolution and fate

Nixon, Conor A.; Lorenz, Ralph D.

Interball-1 observations of flux transfer events

Sibeck, D. G.; Korotova, G. I.; Petrov, V. I.

We present the results of a survey of 807 FTEs observed by Interball-1 on the mid- and high-latitude dayside and flank magnetopause. Dayside magnetosheath events show a strong tendency to occur for southward magnetosheath magnetic fields suggesting origin via component (or perhaps antiparallel) reconnection near the equatorial plane. Flank FTEs oc…

Monte-Carlo Simulations of the Suzaku-XRS Residual Background Spectrum

Piro, L.; Santangelo, A.; Mitsuda, K. +7 more

Cryogenic micro-calorimeters are suitable to detect small amounts of energy deposited by electromagnetic and nuclear interactions, which makes them attractive in a variety of applications on ground and in space. The only X-ray micro-calorimeter that operated in orbit to date is the X-Ray Spectrometer on-board of the Japanese Suzaku satellite. We d…

A multifrequency approach of the cosmological parameter estimation in the presence of extragalactic point sources

Aghanim, N.; Douspis, M.; Finelli, F. +4 more

We present a multifrequency approach which optimizes the constraints on cosmological parameters with respect to extragalactic point source and secondary anisotropy contamination on small scales. We model with a minimal number of parameters the expected dominant contaminations in intensity, such as unresolved point sources and the thermal Sunyaev-Z…

Star formation history and environment of the dwarf galaxy UGCA 92

Makarova, Lidia; Makarov, Dmitry; Savchenko, Sergey

We present a quantitative star formation history of the nearby dwarf galaxy UGCA 92. This irregular dwarf is situated in the vicinity of the Local Group of galaxies in a zone of strong Galactic extinction (IC 342 group of galaxies). The galaxy was resolved into stars, including the old red giant branch, with HST/ACS. We constructed a model of the …