Neutrino-driven turbulent convection and standing accretion shock instability in three-dimensional core-collapse supernovae

Abstract

We conduct a series of numerical experiments into the nature of three-dimensional (3D) hydrodynamics in the postbounce stalled-shock phase of core-collapse supernovae using 3D general-relativistic hydrodynamic simulations of a 27-M progenitor star with a neutrino leakage/heating scheme. We vary the strength of neutrino heating and nd three cases of 3D dynamics: (1) neutrino-driven convection, (2) initially neutrino-driven convection and subsequent development of the standing accretion shock instability (SASI), (3) SASI dominated evolution. This con rms previous 3D results of Hanke et al. (2013), ApJ 770:66 and Couch & Connor (2014), ApJ 785:123. We carry out simulations with resolutions di ering by up to a factor of 4 and demonstrate that low resolution is arti cially favorable for explosion in the 3D convection-dominated case, since it decreases the e ciency of energy transport to small scales. Low resolution results in higher radial convective uxes of energy and enthalpy, more fully buoyant mass, and stronger neutrino heating. In the SASI-dominated case, lower resolution damps SASI oscillations. In the convection-dominated case, a quasi-stationary angular kinetic energy spectrum E(`) develops in the heating layer. Like other 3D studies, we nd E(`) / `����1 in the \inertial range," while theory and local simulations argue for E(`) / `����5=3. We argue that current 3D simulations do not resolve the inertial range of turbulence and are a ected by numerical viscosity up to the energy containing scale, creating a \bottleneck" that prevents an e cient turbulent cascade