Star-disc interactions near a massive black hole
Abstract
The possibility that stars in the nuclei of galaxies could be 'ground down' into short-period orbits, by interaction with a disk around a central massive black hole is examined. A star on a highly eccentric orbit, which passed close to the hole, would lose energy and momentum in passing through the disk. The cumulative effect of many passages would bring the star into a circular orbit corotating with the disk. The star would then either open up a gap in the disk (if the disk is thinner than the star's Roche radius and the viscosity in the disk is sufficiently low), or accrete material from the disk. By these processes, stars could, without prior disruption, acquire orbits whose binding energy to the hole greatly exceeds their self-binding energy, and may even be relativistic. There are possible implications for the fueling and variability of AGN. In particular, a star on a tight bound orbit could modulate the luminosity in a periodic fashion.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- June 1991
- DOI:
- 10.1093/mnras/250.3.505
- Bibcode:
- 1991MNRAS.250..505S
- Keywords:
-
- Active Galactic Nuclei;
- Black Holes (Astronomy);
- Gravitational Effects;
- Stellar Orbits;
- Stellar Luminosity;
- Stellar Mass Accretion;
- Astrophysics