STABILITY OF AN ISOTHERMAL MAGNETIZED ACCRETION DISK WITH CAUSALLY LIMITED VISCOSITY AND RADIAL VISCOUS FORCE

The stability of an isothermal, magnetized, radial viscosity and causa lly limited viscosity accretion disk is examined in this paper. We fin d that the viscous modes are always stable throughout the disk, and th at the magneto-acoustic modes are pulsationally unstable. We also get some useful instability conditions. The numerical calculation results show that the Mach numbers do affect the instabilities of the disk. Th e radial viscosity damps the instability and the magnetic field enhanc es the instability of the radial oscillation. Our results are useful f or understanding the time variations of AGN.