Doppler Modulation of X-ray lines in Cygnus X-3
Astrophysics
2009-11-07 v2
Abstract
We measured Doppler shifts of three bright spectral lines in the X-ray emission from Cygnus X-3 as recorded by the Chandra X-Ray Observatory. Doppler shifts of lines associated with Si XIV and S XVI exhibit orbital modulation. The magnitude and phasing of this modulation relative to the orbital ephemeris indicate the location of the source of this emission within the wind emanating from the compact object's companion. These observations enable us to make an indirect measurement of the separation of the two stars. Under certain assumptions our observation of a line associated with Fe XXV also limits the mass of the compact object M < 3.6 MSun.
Cite
@article{arxiv.astro-ph/0301554,
title = {Doppler Modulation of X-ray lines in Cygnus X-3},
author = {Michael J. Stark and Malinda Saia},
journal= {arXiv preprint arXiv:astro-ph/0301554},
year = {2009}
}
Comments
7 pages, 3 figures, Accepted for publication in The Astrophysical Journal Letters