Radiatively Driven Mass Accretion onto Galactic Nuclei by Circumnuclear Starbursts

We examine the radiatively driven mass accretion onto galactic nuclei due to the intensive radiation from circumnuclear starbursts. The radiation from a starburst not only contracts an inner gas disk by the radiation flux force, but also extracts angular momenta due to the relativistic radiation drag, thereby inducing an avalanche of the surface layer of disk. The present radiatively driven mass accretion may provide a physical mechanism which enables mass accretion from 100 pc scales down to pc, and it can eventually link to an advection-dominated viscous accretion onto a massive black hole. The radiation-hydrodynamical and self-gravitational instabilities of the disk are briefly discussed. In particular, the radiative acceleration possibly builds up a dusty wall, which provides another version for the formation of an obscuring torus.