An X-ray Analysis of α Cru
M. Gorski1, R. Ignace2 and L.M. Oskinova3
2 East Tennessee State University, USA
3 Institut für Physik und Astronomie, Universität Potsdam, Germany
The star α Cru is an early B type subgiant star recently observed by the Chandra Space Telescope. This star is of particular interest due to the observed x-ray emission produced by shocks that form in the stellar wind. We observe hydrogen like O VIII and helium like O VII spectral lines in the Low Energy Transmission Grating spectrum. The O VII produces characteristic triplet line. We provide an analysis of the helium like triplet that explains the conditions in the stellar wind where that line emission is formed. α Cru is also an ultraviolet bright star, so an International Ultraviolet Explorer observation is used to explain the effect of ultraviolet pumping on the forbidden component of the α triplet line. The data appear basically consistent with theoretical models of shocks in stellar winds by Owocki, Castor, & Rybicki (1988) and Feldmeier et al. (1997).