Andrzej A. Zdziarski, Joanna Mikolajewska, Krzysztof Belczynski
The Galactic X-ray binary Cyg X-3 consists of a compact object wind-fed by a Wolf-Rayet (WR) star. We determine its binary parameters and the mass-loss rate. Using the published infrared and X-ray data, we calculate the mass ratio and inclination. Then we fit the dependence of the mass-loss rate on the mass for WR stars of the WN type, and take into account a relation between the mass-loss rate and the binary period derivative, observed to be >0 in Cyg X-3. This allows us to solve for the masses, inclination and mass-loss rate in the system. Our obtained mass-loss rate is almost identical to that from two independent estimates and consistent with other ones, which strongly supports the validity of this solution. We obtain the WR and compact object masses as 10.3(-2.8,+3.9), 2.4(-1.1,+2.1) solar masses, respectively. Thus, either a neutron star or a low-mass black hole can be present. However, the radio, infrared and X-ray properties of the system suggest that the compact object is a black hole.
View original:
http://arxiv.org/abs/1208.5455
No comments:
Post a Comment