Magnetic field advection in weakly magnetised viscous resistive accretion disks: Numerical simulations

Abstract

Observations of jets from accretion disks have constrained the launching radius to be confined to a zone close to the centre of the disk. The time evolution of a viscous, resistive accretion disk with a radially varying magnetisation distribution is studied. The magnetic field is advected into the centre of the disk over two accretion timescales. The magnetic field distribution evolves towards a power law. The field lines bend sharply near the disk surface. A super-fast magnetosonic wind is launched from the innermost region of the disk due to numerical effects.