The Dynamics of Neutrino-Driven Supernova Explosions after Shock Revival in 2D and 3D

TL;DR

This study compares 2D and 3D neutrino-driven supernova explosion simulations, revealing that 3D models exhibit more steady and rapid energy growth, while 2D models face energy and outflow limitations due to instabilities and flow dynamics.

Contribution

It provides detailed 2D and 3D simulation analysis of supernova explosions, highlighting the differences in explosion energy growth and the impact of instabilities on outflows.

Findings

3D models show faster, steadier energy growth

2D models have unsteady energy growth and lower outflow rates

Rayleigh-Taylor instability hampers 2D explosion energy growth

Abstract

We study the growth of the explosion energy after shock revival in neutrino-driven explosions in two and three dimensions (2D/3D) using multi-group neutrino hydrodynamics simulations of an $11.2 M_\odot$ star. The 3D model shows a faster and steadier growth of the explosion energy and already shows signs of subsiding accretion after one second. By contrast, the growth of the explosion energy in 2D is unsteady, and accretion lasts for several seconds as confirmed by additional long-time simulations of stars of similar masses. Appreciable explosion energies can still be reached, albeit at the expense of rather high neutron star masses. In 2D, the binding energy at the gain radius is larger because the strong excitation of downward-propagating g-modes removes energy from the freshly accreted material in the downflows. Consequently, the mass outflow rate is considerably lower in 2D than in 3D. This is only partially compensated by additional heating by outward-propagating acoustic waves in 2D. Moreover, the mass outflow rate in 2D is reduced because much of the neutrino energy deposition occurs in downflows or bubbles confined by secondary shocks without driving outflows. Episodic constriction of outflows and vertical mixing of colder shocked material and hot, neutrino-heated ejecta due to Rayleigh-Taylor instability further hamper the growth of the explosion energy in 2D. Further simulations will be necessary to determine whether these effects are generic over a wider range of supernova progenitors.