DYNAMICS OF ROTATING ACCRETION FLOWS IRRADIATED BY A QUASAR

摘要

We study the axisymmetric, time-dependent hydrodynamics of rotating flows that are under the influence of super-massive black hole gravity and radiation from an accretion disk surrounding the black hole (BH). This work is an extension of the earlier work presented by Proga, in which nonrotating flows were studied. Here, we consider effects of rotation, a position-dependent radiation temperature, density at large radii, and uniform X-ray background radiation. As in the nonrotating case, the rotating flow settles into a configuration with two components, (1) an equatorial inflow and (2) a bipolar inflow/outflow with the outflow leaving the system along the pole. However, with rotation the flow does not always reach a steady state. In addition, rotation reduces the outflow collimation and the outward flux of mass and kinetic energy. Moreover, rotation increases the outward flux of the thermal energy and can lead to fragmentation and time variability of the outflow. We also show that a position-dependent radiation temperature can significantly change the flow solution, In particular, the inflow in the equatorial region can be replaced by a thermally driven outflow. Generally, as has been discussed and shown in the past, we find that self-consistently determined preheating/ cooling from the quasar radiation can significantly reduce the rate at which the central BH is fed with matter. However, our results also emphasize a little-appreciated feature. Namely, quasar radiation drives a nonspherical, multitem-perature, and very dynamic flow. These effects become dominant for luminosities in excess of 0.01 of the Eddington luminosity.