New Insights into the X-ray Sources in Hot Star Winds
Nathan A. Miller, Joseph P. Cassinelli (University of Wisconsin-Madison), Wayne L. Waldron (Emergent-IT), Joseph J. MacFarlane (Prism Computational Sciences) David H. Cohen (Swarthmore College, Prism Computational Sciences )
Abstract
The HETG X-ray emission-line spectra of hot stars have revealed a
suprising diversity of characteristics. Although all the early-type
stars we have observed have shown extremely broad emission lines
(
500-1000 km s-1 HWHM), only
Puppis has shown
the line-centroid blue-shifting expected from wind optical depth
effects. Using helium-like ion line diagnostics, it appears that the
hardest X-rays in both
Pup and
Ori originate close to
their photospheres, a region where it would be difficult to form
strong shocks. The hard X-ray emission from
Ori originates
from a distance roughly corresponding to its close companion star, so
binary wind effects are discussed as a possible additional X-ray
source.
CATEGORY: NORMAL STARS AND WHITE DWARFS