Numerical simulation of the formation of shock waves in thin accretion disks and the resulting angular momentum transport

Two-dimensional numerical simulations of the formation and propagation of shocks inside a Keplerian disk and their effects on the transport of angular momentum have been performed in order to explore dissipation in shock waves as a possible mechanism for the apparent high viscosity in thin accretion disks. It is found that nonaxisymmetric perturbations produce spiral shaped waves inside the disk, and that the radial behavior of the wave amplitudes can be determined by the position of the corotation radius and the dissipation. Waves moving away from the corotation radius show a strong steepening, along with the formation of shock fronts. Perturbations from the outside are shown to be more efficient for the formation of shock waves in a disk than disturbances initiated from the inside.