Search Publications
Obscured Sources and Supergiant Fast X-ray Transients: New Classes of High Mass X-ray Binaries
Chaty, S.
A new type of high-energy binary systems has been revealed by the INTEGRAL satellite. These sources are in the course of being unveiled by means of multi-wavelength optical, near-and mid-infrared observations. Among these sources, two distinct classes are appearing: the first one is constituted of intrinsically obscured high-energy sources, of whi…
INTEGRAL and Swift Observations of Blazars in Outburst
Ghisellini, G.; Pian, E.; Foschini, L.
The blazars 3C 454.3, PKS 0537-441 and PKS 2155-304 are traditionally known to be among the most active sources of this class. They emit at all frequencies, up to gamma-rays, and are good probes of multiwavelength nuclear variability. The first two also have luminous broad emission line regions. We have recently monitored them with various facilit…
Soft Gamma Repeaters: New Results and Surprises from Swift, INTEGRAL, and the Interplanetary Network
Hurley, K.
The history and observational properties of the soft gamma repeaters are reviewed. Over the past decades, we have gone from viewing these objects as a special class of cosmic gamma-ray burst, to seeing them as one manifestation of magnetars. There is now a solid body of multi-wavelength observations, as well as some more controversial properties. …
New Results on Cataclysmic Variables Observed by INTEGRAL
Gális, R.; Hudec, R.; Šimon, V. +1 more
The results of investigations of cataclysmic variables and related objects with the ESA INTEGRAL satellite mostly within the Core Programme are presented and discussed. It is evident that the INTEGRAL satellite serves as an efficient tool to study some of these objects, especially those containing a magnetic white dwarf.
X-Ray and Optical Followup of Gamma-Ray (up to TeV) Sources
Masetti, N.
The imaging capabilities of the INTEGRAL and HESS observatories allow the study of hard X-ray and TeV sources with unprecedented positional accuracy. Here I review the multiwavelength followup studies which are currently being performed on the unidentified sources detected by these facilities in order to unveil their actual nature.
Microquasars: A Brief Overview and a Snapshot of GRS 1915+105 with INTEGRAL
Rodriguez, J.; Hannikainen, D. C.
Microquasars, sources of relativistic motion, have generated a lot of interest since their discovery. In this paper we shall briefly review some general properties of microquasars, and then focus on some recent observations of one of the more notorious microquasars, GRS 1915+105.
High Resolution and Broad Band Spectra of Low Mass X-ray Binaries: a Comparison between Black Holes and Neutron Stars
Iaria, Rosario; Di Salvo, Tiziana; Burderi, Luciano +1 more
A common question about compact objects in high energy astrophysics is whether it is possible to distinguish black hole from neutron star systems with some other property that is not the mass of the compact object. Up to now a few characteristics have been found which are typical of neutron stars (like quasi periodic oscillations at kHz frequencie…
The MEGA Project for Medium Energy Gamma-ray Astronomy
Hartmann, D. H.; Ajello, M.; Di Cocco, G. +22 more
The Medium Energy Gamma-ray Astronomy (MEGA) telescope concept will soon be proposed as a MIDEX mission. This mission would enable a sensitive all-sky survey of the medium-energy gamma-ray sky (0.4 50 MeV) and bridge the huge sensitivity gap between the COMPTEL and OSSE experiments on the Compton Gamma Ray Observatory and the visionary Advanced Co…
Millisecond Pulsar Population in the Galactic Center and High Energy Contributions
Wang, Wei
We propose that there possibly exists a population of millisecond pulsars in the Galactic center region. Millisecond pulsars (MSPs) could emit GeV gamma-rays through synchrotron-curvature radiation as predicted by outer gap models. In the same time, the compact wind nebulae around millisecond pulsars can emit X-rays though synchrotron radiation an…
Magnetars' Giant Flares: the Case of SGR 1806 20
Mereghetti, Sandro; Turolla, Roberto; Tiengo, Andrea +4 more
We report on the properties of the SGR 1806 20's Giant Flare occurred on 2004 December 27th, with particular interest on the pre and post flare intensity/hardness correlated variability. We show that these findings are consistent with the picture of a twisted internal magnetic field which stresses the star solid crust, until the latter is not able…