Turbulent magnetic field amplification from spiral SASI modes in core-collapse supernovae

TL;DR

This paper introduces MHD simulations of core-collapse supernovae, demonstrating how spiral SASI modes can generate turbulent magnetic fields, which may influence neutron star magnetization but do not alter shock evolution.

Contribution

The study implements MHD in an astrophysical code and explores magnetic field amplification by spiral SASI modes in supernova simulations, revealing turbulence-driven magnetic growth.

Findings

Shear flows from spiral SASI amplify magnetic fields.

Magnetic amplification does not significantly change shock evolution.

SASI may contribute to neutron star magnetization.

Abstract

We describe the initial implementation of magnetohydrodynamics (MHD) in our astrophysical simulation code \genasis. Then, we present MHD simulations exploring the capacity of the stationary accretion shock instability (SASI) to generate magnetic fields by adding a weak magnetic field to an initially spherically symmetric fluid configuration that models a stalled shock in the post-bounce supernova environment. Upon perturbation and nonlinear SASI development, shear flows associated with the spiral SASI mode contributes to a widespread and turbulent field amplification mechanism. While the SASI may contribute to neutron star magnetization, these simulations do not show qualitatively new features in the global evolution of the shock as a result of SASI-induced magnetic field amplification.