Cosmological accretion disks driven by radiation drag.
Abstract
The accretion disk driven by the radiation drag which is exerted by the isotropic cosmic background radiation is analyzed. From a viewpoint of timescales, the drag force seems more efficient than the α-viscosity to transfer angular momenta in high redshifts greater than 200. Steady accretion due to the radiation drag is possible both for a point-mass and dark-matter potentials if the drag coefficient is constant. In the former case, the solution can connect to the center. Also, the non-steady evolution is numerically investigated. The cosmological collapse of a density fluctuation leads to a rigidly rotating accretion disk in a dark-matter potential. The disk shrinks through the angular momentum loss due to the drag. Consequently, the disk evolves into an optically-thick, self-gravitating disk, which is gravitationally unstable for non-axisymmetric modes.
- Publication:
-
Basic Physics of Accretion Disks
- Pub Date:
- 1996
- Bibcode:
- 1996bpad.conf..203U
- Keywords:
-
- Radiation Pressure: Accretion Disks;
- Accretion Disks: Cosmological Models;
- Accretion Disks: Hydrodynamics