Chandra/HETGS Observations of the Capella System: the Primary as a Dominating X-ray Source
Astrophysics
2009-11-11 v1
Abstract
Using the Chandra/High Energy Transmission Grating Spectrometer (hereafter HETGS) we have detected Doppler motion of Capella's X-ray emission lines in the 6 -- 25AA wave-band. The observed motion follows the expected orbital motion of Capella's primary. This finding implies that the primary G8 III star, not the secondary G1 III star in the Hertzsprung gap, has been the dominant source of hot 10^{6.8} -- 10^{7}K plasma at least in the last six years. In addition, the results demonstrate the long-term stability of the HETGS and demonstrate small uncertainties of 25 and 33 km/s in the velocity determination with the HEG and MEG, respectively.
Cite
@article{arxiv.astro-ph/0605383,
title = {Chandra/HETGS Observations of the Capella System: the Primary as a Dominating X-ray Source},
author = {Kazunori Ishibashi and Daniel Dewey and David P. Huenemoerder and Paola Testa},
journal= {arXiv preprint arXiv:astro-ph/0605383},
year = {2009}
}
Comments
4 pages, 4 figures, accepted by Astrophysical Journal Letters