Three-dimensional Core-Collapse Supernova Simulations on the Yin-Yang Grid

Abstract

We perform a set of neutrino-driven core collapse supernova simulations in three dimensions studying the hydrodynamical neutron star (NS) kick mechanism. The computational cost is reduced significantly with the help of an axis-free overlapping grid technique in spherical geometry called the “Yin-Yang” grid. Our simulations follow the evolution of core collapse supernovae from 15 ms after bounce until approximately 1.4 s later. For the first time in three dimensions, our results produce neutron star kick velocities up to ˜600 km/s. Such a high kick velocity results from the highly asymmetric mass distribution in the post-shock region exerting a net gravitational pull on the proto-neutron star on a timescale of a few seconds. With this kick scenario proposed by Scheck et al., NS recoil velocities larger than ˜1000 km/s might as well be possible but require a larger set of models for statistical reasons (connected with the stochastic development of asymmetries). Our simulations also confirm an enhanced production of heavy elements in the direction roughly opposite to the NS recoil direction. This produces a detectable hemispheric asymmetry in the distribution of heavy elements which can be used to constrain the NS kick mechanism.