SELF-REGULATED ACCRETION DISKS

We consider a class of fully self-gravitating accretion disks, for whi ch efficient cooling mechanisms are assumed to maintain the disk close to the margin of Jeans instability. For such self-regulated disks, th e equations become very simple in the outer regions, where the angular momentum convective transport approximately balances the viscous tran sport. These latter equations are shown to lead naturally to a self-si milar solution with a flat rotation curve, with a circular velocity pr oportional to (M)(1/3) and an essentially fixed opening angle.