Wind interactions above accretion discs - A model for broad-line regions and collimated outflow

In the present study of the interaction of a wind from an active galactic nucleus with a Compton heating-induced wind from an accretion disk, the nuclear wind is understood to be supersonic and spherically symmetric initially. The disk wind arises when the disk surface is exposed to a hard and powerful X-ray source. The interaction classes are identified on the basis of the relation between the pressure p(b) on the disk surface and the corresponding thermal and ram pressures, p(t) and p(r), in the nuclear wind: (1) for p(b) greater than p(r), the nuclear wind is shocked within the inner radius of the disk wind and high velocity winds are collimated via the twin-exhaust mechanism; (2) for p(b) between p(r) and p(t), as p(r)/p(b) increases, the interface becomes more oblique to the nuclear wind and closer to the disk; and (3) for p(t) greater than p(b), the disk wind is suppressed.