The relationship between accretion disks and jets

Recent results are reported from a program of large-scale numerical simulation of accretion and jet flows utilizing a code that computes 3-d MHD in full general relativity. We find that outflows arise as a direct consequence of accretion and have a generic geometric form: a funnel along the black hole rotation axis that has very low matter density but strong helical magnetic fields, surrounded by a funnel-wall flow of much greater matter density. Large-scale field is created spontaneously in the funnel as a consequence of accretion, despite the absence of large-scale field originally. Coronal pressure both accelerates and collimates the funnel-wall outflow. The strength of all quantities associated with the outflow is a strongly increasing function of black hole spin parameter a/M. Measured in terms of conventional rest-mass efficiency, both the matter and the electromagnetic components of the outflow can be comparable in power to the radiation expected from the accretion disk.