Revival of a stalled supernova shock by neutrino heating

Abstract

The mechanism for revival of a stalled supernova shock found by Wilson(1982) in a computation is analyzed. Neutrinos from the hot, inner coreof the supernova are absorbed in the outer layers, and although onlyabout 0.1 percent of their energy is so absorbed, this is enough toeject the outer part of the star and leave only enough mass to form aneutron star. The neutrino absorption is independent of the density ofmaterial. After the shock recedes to some extent, neutrino heatingestablishes a sufficient pressure gradient to push the material beyondabout 150 km outward, while the material further in falls rapidly towardthe core. This makes the density near 150 km decrease spectacularly,creating a quasi-vacuum in which the pressure is mainly carried byradiation. This is a perfect condition to make the internal energy ofthe matter sufficient to escape from the gravitational attraction of thestar. The net energy of the outgoing shock is about 4 x 10 to the 50thergs.