GT Observations of Hot Stars: Tau Sco

GTTau Sco is an OB star which shows OVI superionization caused by Xrayionization and the Auger Ionization effect. It has a large Lx/Lbol ratio (ofabout 10E6) and an unusually hard Xray spectrum. It has been suggested thatclumps form in the stellar wind, stagnate and fall inward. Because of the highshock velocity that this model predicts, the temperatures in the wind can beunusually hard: high enough that the XMM spectra should show lines of ionizationstages that can place strong constraints on the structure of the Xray formingregions of the star. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]