A two-dimensional supernova model with rotation and nuclear burning

Abstract

The final evolution of a rotating 25 M 0 star is considered. Previous one-dimensional calculations of core collapse in this star have found a weak bounce at nuclear density that, at least in models constructed thus far, does not appear capable of ejecting matter or producing an optical supernova display. When the post-core-bounce evolution is recalculated including rotation in a two-dimensional model, however, we find that a supernova explosion can result. The explosion mechanism is a rotationally induced bounce in the equatorial plane amplified by the energy liberated from nuclear burning. Both explosive nuclear burning and rotation appear to be integral elements in this model, and neither one alone will suffice. In a typical explosion, outward kinetic energies in excess of 10 50 ergs are developed, and more than 0.5 M 0 of mantle material reaches escape velocity, including a substantial fraction of nuclei freshly synthesized by explosive oxygen burning. Mass ejection is initially centered in the equatorial plane, and supernova remnants with toroidal symmetry are a possible outcome. Large amounts of angular momentum remaining in the collapsed remnant, which may become a black hole, appear favorable for gravitational wave generation. Nucleosynthesis and the sensitivity of model results to assumed parameterization are discussed.