Magnetic braking in low-mass X-ray binaries.
Abstract
It is pointed out that the cool main-sequence components of cataclysmic binaries and low-mass X-ray binaries will undergo rotational braking by a magnetically coupled stellar wind, in a way similar to single main-sequence stars. Since the low-mass components of close binaries are forced by tidal forces to remain in corotation, this leads to a loss of orbital angular momentum from the system, and to an enhanced mass-transfer rate. Using the empirical braking law for cool main-sequence stars, it is found that in systems with secondary mases equal to, or greater than 0.3 to 0.5 solar masses the induced mass-transfer rate is larger than that produced by gravitational radiation losses. For a secondary mass of 0.8 solar masses, a mass transfer rate of 10 to the -8.5th is achieved, sufficient to power the brightest low mass X-ray binaries.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- July 1981
- Bibcode:
- 1981A&A...100L...7V
- Keywords:
-
- Binary Stars;
- Stellar Magnetic Fields;
- Stellar Mass Accretion;
- Stellar Rotation;
- X Ray Binaries;
- X Ray Sources;
- Angular Momentum;
- Gravitational Effects;
- Gravitational Waves;
- Magnetic Effects;
- Main Sequence Stars;
- Mass Transfer;
- Spin Reduction;
- Stellar Temperature;
- Stellar Winds;
- Astrophysics