X-ray Spectroscopy of the Contact Binary VW Cephei
Abstract
Short-period binaries represent extreme cases in the generation of stellar coronae via a rotational dynamo. Such stars are important for probing the origin and nature of coronae in the regimes of rapid rotation and activity saturation. VW Cep (P=0.28 d) is a relatively bright, partially eclipsing, and very active object. Light curves made from Chandra/HETGS data show flaring and rotational modulation, but no eclipses. Velocity modulation of emission lines indicates that one component dominates the X-ray emission. The emission measure is highly structured, having three peaks. Helium-like triplet lines give electron densities of about 3.0E+10 - 18.0E+10 /cm^3. We conclude that the corona is predominantly on the polar regions of the primary star and compact.
Cite
@article{arxiv.astro-ph/0606690,
title = {X-ray Spectroscopy of the Contact Binary VW Cephei},
author = {David P. Huenemoerder and Paola Testa and Derek L. Buzasi},
journal= {arXiv preprint arXiv:astro-ph/0606690},
year = {2008}
}
Comments
Accepted for publication in the Astropysical Journal, 23 June 2006; 22 pages, 15 figures