Matter Mixing in Aspherical Core-collapse Supernovae: Three-dimensional Simulations with Single Star and Binary Merger Progenitor Models for SN 1987A

TL;DR

This study uses 3D hydrodynamic simulations to explore matter mixing in aspherical core-collapse supernovae, highlighting the significance of binary merger progenitors and bipolar explosion geometries in matching observed features of SN 1987A.

Contribution

It introduces a detailed 3D simulation framework comparing multiple progenitor models, emphasizing the effectiveness of binary merger progenitors in reproducing supernova observations.

Findings

Binary merger progenitor models best reproduce high-velocity $^{56}$Ni features.

Aspherical bipolar explosions align with observed supernova asymmetries.

The model predicts the explosion axis, neutron star kick velocity, and direction.

Abstract

We perform three-dimensional hydrodynamic simulations of aspherical core-collapse supernovae focusing on the matter mixing in SN 1987A. The impacts of four progenitor (pre-supernova) models and parameterized aspherical explosions are investigated. The four pre-supernova models include a blue supergiant (BSG) model based on a slow merger scenario developed recently for the progenitor of SN 1987A (Urushibata et al. 2018). The others are a BSG model based on a single star evolution and two red supergiant (RSG) models. Among the investigated explosion (simulation) models, a model with the binary merger progenitor model and with an asymmetric bipolar-like explosion, which invokes a jetlike explosion, best reproduces constraints on the mass of high velocity $^{56}$Ni, as inferred from the observed [Fe II] line profiles. The advantage of the binary merger progenitor model for the matter mixing is the flat and less extended $\rho \,r^3$ profile of the C+O core and the helium layer, which may be characterized by the small helium core mass. From the best explosion model, the direction of the bipolar explosion axis (the strongest explosion direction), the neutron star (NS) kick velocity, and its direction are predicted. Other related implications and future prospects are also given.