Abstract:

We request multi-fiber optical spectroscopic observations (using the AAOmega/2dF spectrograph at AAT) of the central region of the Small Magellanic Cloud, in order to determine the donor type of the identified X-ray binaries (XRBs) detected in our large XMM survey of the same area. This way we will unambiguously classify the XRBs into Be (easily identifiable by their Hα emission) or supergiant systems. These observations will create a complete census of early-type line-emitting SMC stars down to V~19 mag, thus allowing to address: i) the fraction of early-type stars that exhibit Hα emission and the connection between their Hα excess and red excess or brightness, ii) the fraction of such sources that are observed in X-rays, which is important for constraining the formation rate of accreting binaries in an environment with well characterized stellar populations, and iii) the spectral-type distribution of low-luminosity XRBs.

Website