Multidimensional Radiation Hydrodynamics Simulations of SN 1987A Shock Breakout

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) multiwavelength radiation hydrodynamics simulations of SN 1987A shock breakout by using the CASTRO code with the OPAL opacity table considering eight photon groups from infrared to X-ray. To investigate the impact of the pre-SN environment of SN 1987A, we consider three possible circumstellar medium 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-long duration and a peak luminosity of ∼4 × 1046 erg s−1, with a decay rate of ∼3.5 mag hr−1 in X-ray. The dominant band transits to UV around 3 hr after the initial breakout, and its luminosity has a decay rate of ∼1.5 mag hr−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 SN remnant formation.