Oblique Shock Breakout in Supernovae and Gamma-Ray Bursts: II. Numerical Solutions For Non-Relativistic Pattern Speeds

TL;DR

This paper presents two-dimensional numerical simulations of non-radial shock emergence in supernovae and related phenomena, revealing complex flow patterns, shock curvature, and flow disturbances that influence ejecta speeds and shock breakout emissions.

Contribution

It introduces detailed 2D simulations of non-radial shock breakout in non-relativistic supernova models, analyzing flow dynamics and boundary effects with implications for radiation and gravity influences.

Findings

Shock front curves toward the stellar surface.

Flow around shock emergence is non-steady and non-self-similar.

Waves and vortices originate near shock breakout region.

Abstract

Non-spherical explosions develop non-radial flows as the pattern of shock emergence progresses across the stellar surface. In supernovae these flows can limit ejecta speeds, stifle shock breakout emission, and cause collisions outside the star. Similar phenomena occur in stellar and planetary collisions, tidal disruption events, accretion-induced collapses, and propagating detonations. We present two-dimensional, nested-grid Athena simulations of non-radial shock emergence in a frame comoving with the breakout pattern, focusing on the adiabatic, non-relativistic limit in a plane stratified envelope. We set boundary conditions using a known self-similar solution and explore the role of box size and resolution on the result. The shock front curves toward the stellar surface, and exhibits a kink from which weak discontinuities originate. Flow around the point of shock emergence is neither perfectly steady nor self-similar. Waves and vortices, which are not predominantly due to grid effects, emanate from this region. The post-shock flow is deflected along the stellar surface, and its pressure disturbs the stellar atmosphere upstream of the emerging shock. We use the numerical results and their analytical limits to predict the effects of radiation transfer and gravity, which are not included in our simulations.