Multidimensional Radiation Hydrodynamics Simulations of Supernova 1987A Shock Breakout

TL;DR

This study presents the first 2D multi-wavelength radiation hydrodynamics simulations of SN 1987A's shock breakout, revealing how pre-supernova environments and multidimensional mixing influence the emission characteristics and asymmetry of the explosion.

Contribution

It introduces detailed 2D simulations of SN 1987A's shock breakout considering various circumstellar environments and highlights the impact of multidimensional mixing on shock dynamics and emission.

Findings

Breakout lasts about an hour with peak luminosity ~4×10^{46} erg/s.

The dominant emission band shifts from X-ray to UV around 3 hours post-breakout.

Pre-explosion environment significantly affects the breakout emission features.

Abstract

Shock breakout is the first electromagnetic signal from supernovae (SNe), which contains important information on the explosion energy and the size and chemical composition of the progenitor star. This paper presents the first two-dimensional (2D) multi-wavelength radiation hydrodynamics simulations of SN 1987A shock breakout by using the $\texttt{CASTRO}$ code with the opacity table, $\texttt{OPAL}$, considering eight photon groups from infrared to X-ray. To investigate the impact of the pre-supernova environment of SN 1987A, we consider three possible circumstellar medium (CSM) environments: a steady wind, an eruptive mass loss, and the existence of a companion star. In sum, the resulting breakout light curve has an hour duration and its peak luminosity of $\sim 4\times 10^{46}\,\rm{erg\,s^{-1}}$ then following a decay rate of $\sim 3.5\,\rm{mag\,hour^{-1}}$ in X-ray. The dominant band transits to UV around 3 hours after the initial breakout, and its luminosity has a decay rate of $\sim 1.5\,\rm{mag\,hour^{-1}}$ that agrees well with the observed shock breakout tail. The detailed features of breakout emission are sensitive to the pre-explosion environment. Furthermore, our 2D simulations demonstrate the importance of multidimensional mixing and its impacts on shock dynamics and radiation emission. The mixing emerging from the shock breakout may lead to a global asymmetry of SN ejecta and affect its later supernova remnant formation.