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 find 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 confirms previous 3D results of Hanke et al. (2013), ApJ 770:66 and Couch & Connor (2014), ApJ 785:123. We carry out simulations with resolutions differing by up to a factor of ∼4 and demonstrate that low resolution is artificially favorable for explosion in the 3D convection-dominated case, since it decreases the efficiency of energy transport to small scales. Low resolution results in higher radial convective fluxes 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 find 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 affected by numerical viscosity up to the energy containing scale, creating a "bottleneck" that prevents an efficient turbulent cascade.

General-Relativistic Three-Dimensional Multi-Group Neutrino Radiation-Hydrodynamics Simulations of Core-Collapse Supernovae

“…As some of us found in the parameterized 3D simulations of Abdikamalov et al (2015), lower resolution appears to be more favorable for shock runaway for simulations near the threshold of explosion (cf. Radice et al 2016).…”

“…We draw from Woosley et al (2002) the progenitor model s27, which has been studied in a number of previous works (e.g., Müller et al 2012a;Hanke et al 2013;Ott et al 2013;Couch & O'Connor 2014;Abdikamalov et al 2015). In all simulations, we employ the = K 220 MeV 0 variant of the equation of state of Lattimer & Swesty (1991) .…”

“…The total energy is directly related to the effective turbulent pressure, which can contribute significantly to the total pressure in the postshock region and aid shock expansion. Abdikamalov et al (2015) suggested that the resolution dependence of CCSN simulations is due to differences in the spectrum of turbulence with different effective numerical viscosities. However, their Figure 13 shows little resolution dependence on the turbulent kinetic energy at the large energy-containing scales that contributed most to the turbulent pressure.…”

The Development of Explosions in Axisymmetric Ab Initio Core-Collapse Supernova Simulations of 12–25 Stars

“…The dynamic behavior of the accretion shock has not received the attention afforded the SASI and convection, but previous analyses using tracer particles from CHIMERA simulations has shown that much of the matter passing through the shock is directed toward the proto-NS in accretion streams (Chertkow et al 2012;Lentz et al 2012a). We notethat the one or two accretion streams that dominate the accretion in 2D simulations is not characteristic of 3D simulations, which exhibit more numerous but weaker accretion streams Tamborra et al 2013Tamborra et al , 2014Takiwaki et al 2014;Tamborra et al 2014;Abdikamalov et al 2015;Lentz et al 2015).…”

The two promising scenarios to explode core collapse supernovae

“…In addition to the pre-collapse turbulence, there are post-collapse instabilities in the post-shock inflow toward the neutron star, such as due to heating by neutrinos, and in particular the standing accretion shock instability (SASI; e.g., Blondin et al 2003;Blondin & Mezzacappa 2007;Fernández 2010;Burrows et al 1995;Janka & Mueller 1996;Buras et al 2006a,b;Ott et al 2008;Marek & Janka 2009;Iwakami et al 2014;Abdikamalov et al 2015;Fernández 2015). Most relevant to the jittering jets scenario are the spiral modes of the SASI that carry local angular momentum variations.…”