Supergiant Fast X-ray Transients as transient sources in High Mass X-ray Binaries
Abstract
Supergiant Fast X-ray Transients (SFXTs) represent the most extreme case of X-ray variability in High Mass X-ray Binaries hosting blue supergiant companions. Mainly discovered thanks to the INTEGRAL monitoring of the Galactic plane, these hard X-ray transients display dynamic ranges which can span five orders of magnitude. This intensity variability is associated with accretion onto Galactic compact objects (mostly neutron stars) through a physical mechanism which is still poorly understood. A review of the current status of our understanding on these sources is presented and discussed. Finally, I present recent XMM-Newton results about the SFXT IGRJ16418-4532, proposing that its variability behavior is due to a transitional accretion regime, intermediate between pure wind accretion and Roche Lobe Overflow. This same regime could explain the X-ray activity of other "intermediate" SFXTs with narrow orbits.
Keywords
Cite
@article{arxiv.1111.5747,
title = {Supergiant Fast X-ray Transients as transient sources in High Mass X-ray Binaries},
author = {L. Sidoli},
journal= {arXiv preprint arXiv:1111.5747},
year = {2011}
}
Comments
Invited talk at the conference "The Extreme and Variable High Energy Sky", September 19-23, 2011, Chia Laguna, Sardegna (Italy). 8 pages, 3 figures, accepted for publication on PoS (PoS(Extremesky 2011)010)