Multi-wavelength Signatures of Supernova Shock Breakout from Red Supergiants in Two Dimensions

TL;DR

This study uses two-dimensional radiation hydrodynamic simulations to analyze supernova shock breakout from red supergiants, revealing how radiation precursors and circumstellar media influence observable breakout emissions.

Contribution

It introduces 2D simulations of supernova shock breakout considering circumstellar media, showing effects of radiation precursors and fluid instabilities on breakout signatures.

Findings

Radiation precursors can drive fluid instabilities and alter the photosphere.

Breakout luminosities reach ~10^{44} erg/s, longer and fainter than 1D models.

Dense circumstellar media extend the breakout rise time.

Abstract

We present new two-dimensional radiation hydrodynamic simulations of supernova shock breakout from red supergiants using the $\texttt{CASTRO}$ code. Our progenitors are 20 and 25 M$_{\odot}$ solar-metallicity stars evolved from the zero-age main sequence with $\texttt{MESA}$ and exploded in one dimension using $\texttt{FLASH}$. We consider a range of circumstellar media (CSM) produced by stellar winds to investigate how pre-explosion mass-loss affects shock breakout. The multigroup flux-limited diffusion scheme in $\texttt{CASTRO}$ captures the interaction between the explosion shock, its radiation precursor, and the surrounding CSM. We find that strong radiation precursors, generated by radiation leakage behind the shock, can drive fluid instabilities and move the effective photosphere outward before the shock reaches the stellar surface. The resulting breakout emissions reach peak luminosities of ${\sim}10^{44}$ erg s$^{-1}$ with full-width half-maximum durations of 1-3 hr, , fainter and longer than previous 1D models. The light-curve colors gradually evolve from blue to red after the peak. The 25 M$_{\odot}$ model with explosion energy $E \sim 1.69\times10^{51}$ erg produces ${\sim}$10-30\% higher maximum luminosity than the 20 M$_{\odot}$ model with $E \sim 1.09\times10^{51}$ erg. The dense CSM further extends the breakout rise time by increasing the photon diffusion. These results provide new constraints on red supergiant atmospheres and mass-loss histories prior to core collapse.