The radial-azimuthal instability of a radiation-pressure-dominated accretion disk with advection

A radial-azimuthal instability analysis of a radiation-pressure-dominated a ccretion disk with advection is presented. We find that the including of a very little advection has significant effect on two acoustic modes, which a re no longer complex conjugates of each. other. With the increase of azimut hal perturbations, the thermal mode becomes more unstable and the viscous m ode more stable, but there has no effect on acoustic mode. For geometricall y slim and advection-dominated disks, the azimuthal perturbation and increa sing of advection do not affect the stability of all the modes.