Abstract:

Using Chandra, XMM and optical data (both photometric and spectroscopic), we studied the X-ray binary population in the Small Magellanic Cloud (SMC), down to an X-ray luminosity of ~4×10^33 erg s-1, thus allowing the investigation of the faintest of the high-mass Xraybinary populations. The regions were selected so as to have varying star formation histories, in order to investigate, using homogeneous and well defined samples, the connection between the Be- XRB phenomenon and SF history. The characterization of the X-ray sources discovered in our Chandra and XMM surveys and the selection of our sample of Be-XRBs, was based on a combination of X-ray and optical properties. We found that the number of Be/X-ray binaries (Be-XRBs) peaks at the age of 40-70 Myr ago. Finally, we constructed their X-ray luminosity function (XLF). There are very few X-ray sources above ~10^35 ergs^-1, which is consistent with the transient nature of Be X-ray binaries. There is also indication for a flattening of the XLF at ~10^35 ergs^-1, which would be consistent with the onset of the propeller effect.

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