Anisotropic Neutrino Radiation in Rotational Core Collapse

We have done a series of two-dimensional hydrodynamic simulations of the rotational collapse of a supernova core and estimated the anisotropy of neutrino radiation from nonspherical neutrino spheres. We have employed a realistic equation of state and approximated electron captures and neutrino transport by the so-called leakage scheme. We have calculated heating rates outside the neutrino sphere, assuming that neutrinos are emitted isotropically from each point on the neutrino sphere. We have found that neutrinos heat matter near the rotational axis more strongly than those near the equatorial plane. This might induce a globally anisotropic explosion.