Three-Dimensional General Relativistic Simulations of Core-Collapse Supernovae

Despite decades of effort, the explosion mechanism of core-collapse supernovae is still not well understood. Spherically-symmetric models fail to explode, suggesting that multi-dimensional effects are of crucial importance. Studies in axisymmetry (2D) reveal that the standing accretion shock instability (SASI) and neutrino-driven convection are pivotal ingredients for successful explosions. Axisymmetry, however, is a rather poor approximation of this scenario. 3D studies, on the other hand, are still in their infancy and employ crude approximations. As a result, the exact role of the SASI and convection is still not well established. In this talk, I will present our study of the 3D hydrodynamics of the post-bounce phase of the collapse of a 27 solar-mass star. We perform 3D general-relativistic simulations with a neutrino leakage/heating scheme. In our simulations, neutrino-driven convection becomes the dominant instability and leads to large-scale non-oscillatory deformations of the shock front, resulting in strongly aspherical explosions. Low-l-mode SASI oscillations are present in our models, but saturate at small amplitudes.