Magnetohydrodynamic Origin of Jets from Accretion Disks

摘要

The jets observed to emanate from many compact accreting objects may arise from the twisting of a magnetic field threading a differentially rotating accretion disk which acts to magnetically extract angular momentum and energy from the disk. Two main regimes have been discussed, hydromagnetic outflows, which have a significant mass flux and have energy and angular momentum carried by both matter and electromagnetic field and, Poynting outflows, where the mass flux is negligible and energy and angular momentum are carried predominantly by the electromagnetic field. Here, we give an overview of theoretical and simulation studies of non-relativistic hydromagnetic and Poynting jets and new theoretical work on relativistic Poynting jets from accretion disks.