Parameters of the x-ray binary system Vela X-1 (4U 0900-40 = HD 77581)
Abstract
The inverse problem of the interpretation of optical light curves of the X-ray binary system Vela X-1 has been solved in the framework of the model of a close binary system with an accretion disk surrounding the compact object, revolving around the tidally distorted optical star on an eccentric orbit. It is shown that the parameter of the critical lobe filling μ of the optical star is close to unity only in the orbit periastron. For the most part of the orbital period the optical star has μ ≡ 0.93 - 0.96, i.e. the accretion onto the neutron star is mainly from a stimulated stellar wind of the optical star. The best description of the observations by a theoretical light curve takes place if the neutron star is surrounded by the accretion disk with a small radius rd ≡ 0.02 a (where a is the semimajor axis of the system) and with the optical luminosity close to zero. The obtained parameters of Vela X-1 are i = 73±3°, q = 0.074±0.014, MX = 1.8±0.5 M_sun;, Mopt = 24.3±2.7 M_sun;, if e = 0.08 and ωX = 111°.
- Publication:
-
Astronomicheskii Zhurnal
- Pub Date:
- August 1986
- Bibcode:
- 1986AZh....63..711K
- Keywords:
-
- Accretion Disks;
- Light Curve;
- Stellar Orbits;
- X Ray Binaries;
- Neutron Stars;
- Stellar Luminosity;
- Stellar Models;
- Astrophysics