Document Type
Article
Publication Date
10-20-2006
Published In
Astrophysical Journal
Abstract
We discuss new methods of measuring and interpreting the forbidden-to-intercombination line ratios of heliumlike triplets in the X-ray spectra of O- type stars, including accounting for the spatial distribution of the X-ray-emitting plasma and using the detailed photospheric UV spectrum. Measurements are made for four O stars using archival Chandra HETGS data. We assume an X- ray-emitting plasma spatially distributed in the wind above some minimum radius R-0. We find minimum radii of formation typically in the range of 1.25 < R-0 / R-* < 1.67, which is consistent with results obtained independently from line profile fits. We find no evidence for anomalously low f / i ratios, and we do not require the existence of X-ray-emitting plasmas at radii that are too small to generate sufficiently strong shocks.
Recommended Citation
M. A. Leutenegger et al.
(2006).
"Measurements And Analysis Of Helium-Like Triplet Ratios In The X-Ray Spectra Of O-Type Stars".
Astrophysical Journal.
Volume 650,
Issue 2.
1096-1110.
DOI: 10.1086/507147
https://works.swarthmore.edu/fac-physics/17
Comments
This work is freely available courtesy of IOP Publishing and the American Astronomical Society.