Neutrino-Dominated Accretion and Supernovae

We suggest that part of the infalling material during the core-collapse of a massive star goes into orbit around the compact core to form a hot, dense, centrifugally-supported accretion disk whose evolution is strongly influenced by neutrino interactions. Under a wide range of conditions, this neutrino-dominated accretion flow will be advection-dominated and will develop a substantial outflowing wind. We estimate the energy carried out in the wind and find that it exceeds $10^{50}$ erg for a wide range of parameters and even exceeds 10^{51} erg for reasonable parameter choices. We propose that the wind energy will revive a stalled shock and will help produce a successful supernova explosion. We discuss the role of the disk wind in both prompt and delayed explosions. While both scenarios are feasible, we suggest that a delayed explosion is more likely, and perhaps even unavoidable. Finally, we suggest that the disk wind may be a natural site for r-process nucleosynthesis.