Dynamics of Magnetic Loops in the Coronae of Accretion Disks

Abstract

Axisymmetric magnetohydrodynamic (MHD) simulations are used to study the evolution of general magnetic eld congurations where a magnetic eld B threads di erent radii of a di erentially rotating accretion disk. The di erential rotation of the footpoints of B eld loops at di erent radii on the disk surface causes a twisting of the coronal magnetic eld, an increase in the coronal magnetic energy, and an opening of the loops in the region where the magnetic pressure is larger than the matter pressure