Winds from Hot Accretion Disks

Hydrodynamical winds from hot accretion disks around compact objects are investigated using a simplified model. The flow pattern above the disk is solved assuming that specific angular momentum is conserved along a stream line and that the radial component of the gravitational force balances the centrifugal force everywhere. An isothermal or polytropic relation is also assumed. It is shown that there exists a critical solution for which the flow is subsonic at the disk plane and becomes supersonic beyond the critical point. The mass-loss rate is calculated for the critical solution, and it turns out to be comparable to the accretion rate if the temperature is near the virial temperature. Thus wind loss will significantly affect the properties of hot two-temperature accretion disks.