Search Publications
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…
Search for Dark Matter with GLAST
Morselli, Aldo
The detection of gamma-rays, antiprotons and positrons due to pair annihilation of dark matter particles in the Milky Way halo is a viable techniques to search for supersymmetric dark matter candidates. In particular the EGRET team has seen a convincing signal for a strong excess of emission from the Galactic center that has no simple explanation …
Cataclysmic Variables Observed with INTEGRAL
Simon, Vojtech; Hudec, René; Munz, Filip +1 more
We discuss selected results of observations of cataclysmic variables (CVs) and related objects by the instruments IBIS (far X-ray and gamma-ray imager) and OMC (Optical Monitoring Camera) onboard INTEGRAL. We concentrate on the analysis of the time behaviour of the intermediate polar (IP) V1223 Sgr, seen simultaneously by IBIS and OMC in a state w…
Unveiling the Nature of INTEGRAL Sources Through Optical Spectroscopy
Masetti, Nicola
Since its launch on October 2002 the INTEGRAL satellite is performing an deep survey of the hard X-ray sky with unprecedented sensitivity and positional accuracy. This allowed pinpointing, through positional cross-correlation with catalogs at longer wavelengths, possible optical/near-infrared candidates for the hard X-ray sources of still unknown …
Blazars and INTEGRAL
Pian, E.; Hudec, R.; Kubánek, P. +1 more
We refer to analysis of the ESA INTEGRAL satellite data for specific class of active galactic nuclei - blazars. These objects represent promising sources to be observed by INTEGRAL, especially during their active states. Suitable strategy for the future analysis is proposed and discussed.
Microquasars: What do radio and X-ray observations tell us?
Wu, Kinwah; Rodriguez, Jérôme; Vilhu, Osmi +4 more
Microquasars, or X-ray binaries exhibiting radio jets, have been observed extensively at all wavelengths for the past decade or so. Primarily, they have been observed in the X-ray regimes and the radio. In this paper we review the radio and the X-ray behavior of the first two superluminal microquasars, GRS 1915+105 and GRO J1655-40. We show how GR…