X-ray observations of 4 Draconis: symbiotic binary or cataclysmic triple?
Abstract
We present the first X-ray observations of the 4 Draconis system, consisting of an M3III giant with a hot ultraviolet companion. It has been claimed that the companion is itself an AM Her-type binary system, an identification that places strong constraints on the evolution of cataclysmic variables. We find that the X-ray properties of 4 Draconis are consistent with the presence of an accreting white dwarf, but not consistent with the presence of an AM Her system. We conclude that 4 Dra is therefore most-likely a symbiotic binary containing a white dwarf accreting material from the wind of the red giant. The X-ray spectrum of 4 Dra is sometimes dominated by partially-ionised photoelectric absorption, presumably due to the wind of the red giant. We note that X-ray monitoring of such systems would provide a powerful probe of the wind and mass-loss rate of the giant, and would allow a detailed test of wind accretion models.
Cite
@article{arxiv.astro-ph/0309410,
title = {X-ray observations of 4 Draconis: symbiotic binary or cataclysmic triple?},
author = {Peter J. Wheatley and Koji Mukai and Domitilla de Martino},
journal= {arXiv preprint arXiv:astro-ph/0309410},
year = {2016}
}
Comments
6 pages, 6 figures, accepted for publication in MNRAS