In the last decade a new population of X-ray transients has been discovered. They show anomalously low peak luminosities (2-10 keV) of 1E34 to 1E36 ergs/s. A large fraction of them is expected to harbor accreting neutron stars and black holes in binaries systems.These very faint X-ray binaries provide a new regime to study accretion onto compact objects, and therefore they can improve our understanding of accretion physics and binary evolution models. We report the study of the 2011 outburst evolution of the newly discovered black hole candidate X-ray binary Swift J1357.2-0933. We analyzed the Swift X-ray telescope and Ultraviolet/Optical telescope (UVOT) data taken during the outburst. The low column density towards the source and its proximity (~1.5 kpc) provides an exceptional opportunity to study the X-ray spectrum and the optical counterpart in unprecedented detail and search for features such as X-ray bursts, X-ray pulsations and eclipses/dips in the X-ray lightcurve. Its peak luminosity of ~1E35 ergs/s classifies the source as a very faint X-ray transient. If the black hole nature is confirmed, Swift J1357.2-0933 would be the first established black hole very-faint X-ray binary.
|Original language||English (US)|
|Journal||Half a Century of X-ray Astronomy, Proceedings of the conference held 17-21 September, 2012 in Mykonos Island, Greece|
|State||Published - Sep 1 2012|