Stationary spherical accretion into black holes II. Theory of optically thick accretion.
Abstract
The problem of spherical, steadystate, optically thick accretion into black holes is solved. The integral curves of the differential equations describing the problem are analyzed, and a oneparameter family of critical points is found where the inflow velocity equals the isothermal sound speed. A complete set of boundary conditions is obtained which the solution must satisfy at the black hole horizon, and it is shown that these, as well as the requirement that the solution pass through a critical point, determine a unique solution to the problem. A generalization of the Bondi critical point constraint is found which arises in the adiabatic accretion problem and which is effective at the point where the inflow velocity equals the adiabatic sound speed, and it is shown that this point can be regarded as a diffused critical point. The analysis yields a simple expression for the diffusive luminosity at radial infinity, and the critical point structure is explained.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 June 1982
 DOI:
 10.1093/mnras/199.4.833
 Bibcode:
 1982MNRAS.199..833F
 Keywords:

 Astrophysics;
 Black Holes (Astronomy);
 Critical Point;
 Gravitation Theory;
 Stellar Mass Accretion;
 Adiabatic Conditions;
 Interstellar Gas;
 Optical Thickness;
 Steady State;
 Stellar Envelopes;
 Astrophysics;
 Accretion:Black Holes