Disk-accretion onto a black hole. I. Time-averaged structure of accretion disk

An analysis is given of the time-averaged structure of a disk of material accreting onto a black hole. The analysis is valid even if the disk is highly dynamical. It assumes only that the hole is stationary and axially symmetric (e.g., that it is a Kerr hole); that the disk lies in the equatorial plane of the hole, with its material moving in nearly geodesic circular orbits; that the disk is thin; and that radial heat transport is negligible compared with heat losses through the surface of the disk. The most important result of the analysis is an explicit, algebraic expression for the radial dependence of the time-averaged energy flux emitted from the disk's surface, F(r). Subject headings: binaries - black holes