090057

We request 35ks exposure time to measure X-ray spectra of two prototypical massive binary Be stars with sdO companions. We aim to probe the theory which predicts that Be-type stars are the products of close binary evolution and that a significant fraction of them have hot companions which were stripped of hydrogen by a mass exchange. These hot ..stripped. companions with sdO spectral types drive stellar winds which could collide and interact with the Be star winds and disks and hence have unique signatures in their X-ray emission. The two prototypical Be+sdO systems phi Per and o Pup probe different orbital configurations primary.s spectral types and sdO-star mass. Comparative analysis of their X-ray spectra will uncover leading processes responsible for plasma heating in Be+sdO stars. [truncated! Please see actual data for full text]