Three‐Dimensional Simulations of Standing Accretion Shock Instability in Core‐Collapse Supernovae

Abstract

We have studied nonaxisymmetric standing accretion shock instabilities, or SASI, using three-dimensional (3D) hydrodynamical simulations. This is an extension of our previous study of axisymmetric SASI. We have prepared a spherically symmetric and steady accretion flow through a standing shock wave onto a protoYneutron star, taking into account a realistic equation of state and neutrino heating and cooling. This unperturbed model is meant to represent approximately the typical postbounce phase of core-collapse supernovae. We then added a small perturbation ($1%) to the radial velocity and computed the ensuing evolutions. Both axisymmetric and nonaxisymmetric perturbations have been imposed. We have applied mode analysis to the nonspherical deformation of the shock surface, using spherical harmonics. We have found that (1) the growth rates of SASI are degenerate with respect to the azimuthal index m of the spherical harmonics Y m l , just as expected for a spherically symmetric background; (2) nonlinear mode couplings produce only m ¼ 0 modes for axisymmetric perturbations, whereas m 6 ¼ 0 modes are also generated in the nonaxisymmetric cases, according to the selection rule for quadratic couplings; (3) the nonlinear saturation level of each mode is lower in general for 3D than for 2D, because a larger number of modes contribute to turbulence in 3D; (4) low-l modes are dominant in the nonlinear phase; (5) equipartition is nearly established among different m modes in the nonlinear phase; (6) spectra with respect to l obey power laws with a slope slightly steeper for 3D; and (7) although these features are common to the models with and without a shock revival at the end of the simulation, the dominance of low-l modes is more remarkable in the models with a shock revival.

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

“…A fourth group has used a version of the Zeus-MP code (Hayes et al 2006;Iwakami et al 2008Iwakami et al , 2009a for hydrodynamics and the IDSA scheme for neutrino transport (Liebendörfer et al 2009), which we will refer to as "Zeus +IDSA." Zeus+IDSA is fully Newtonian and the transport omits inelastic (energy exchanging) scattering in favor of the elastic versions.…”

On the Impact of Three Dimensions in Simulations of Neutrino-Driven Core-Collapse Supernova Explosions

“…A number of early 3D simulations utilized the smoothed-particle hydrodynamics approximation (Fryer & Warren 2002, 2004Fryer & Young 2007), which has certain disadvantages over grid-based codes (see, e.g., Plewa 2001;Agertz et al 2007;McNally et al 2012;Sijacki et al 2012). Studies of the SASI have made various approxima-tions to achieve 3D simulations (Blondin & Mezzacappa 2007;Iwakami et al 2008Iwakami et al , 2009Fernández 2010). Simulations neglecting the effects of neutrinos and employing a simplified equation of state (EOS) have been used to study the amplification of magnetic fields in 3D (Endeve et al 2010(Endeve et al , 2012.…”

Systematic features of axisymmetric neutrino-driven core-collapse supernova models in multiple progenitors

“…For low-mass progenitors with O-NeMg core, the neutrino mechanism works successfully to explode in one-dimensional (1D) simulations because of the tenuous envelope (Kitaura et al 2006). For more massive progenitors with iron core, multi-dimensional (multi-D) effects such as neutrino-driven convection (e.g., Bethe 1990;Herant et al 1994;Burrows et al 1995;Janka & Müller 1996;Müller & Janka 1997) and the standing-accretion-shock-instability (SASI, Blondin et al 2003;Foglizzo et al 2006;Foglizzo et al 2007;Ohnishi et al 2006;Blondin & Mezzacappa 2007;Iwakami et al 2008;Iwakami et al 2009;Fernández & Thompson 2009;Hanke et al 2012; 2012; Couch 2013;Fernández et al 2014, see Foglizzo et al 2015 for a review) have been suggested to help the onset of the neutrino-driven explosion. Recently this has been confirmed by a number of self-consistent two-(2D) and three-dimensional (3D) simulations (e.g., Buras et al 2006;Ott et al 2008;Marek & Janka 2009;Bruenn et al 2013;Suwa et al 2010;Suwa et al 2014;Müller et al 2012a;Müller et al 2013;Takiwaki et al 2012;Takiwaki et al 2014;Hanke et al 2013;Dolence et al 2014;Bruenn et al 2014;Müller & Janka 2014, see Mezzacappa et al 2015Burrows 2013;Kotake et al 2012 for recent review)).…”