Effects of Dimensionality on Pair-Instability Supernova Explosions

TL;DR

This study investigates how the dimensionality of simulations (1D, 2D, 3D) affects the explosion dynamics and light curves of pair-instability supernovae, revealing minimal impact on observable light curve shapes.

Contribution

It provides the first systematic comparison of PISN explosion simulations across multiple dimensions, highlighting the effects of mixing on ejecta structure.

Findings

Multidimensional simulations show slightly shallower abundance gradients.

Synthetic light curves are largely unaffected by simulation dimensionality.

Mixing at shell boundaries is enhanced in higher-dimensional models.

Abstract

Since the emergence of the new class of extremely bright transients, super-luminous supernovae (SLSNe), three main mechanisms to power their light curves (LCs) have been discussed. They are the spin-down of a magnetar, interaction with circumstellar material, and the decay of large amounts of radioactive nickel in pair-instability supernovae (PISNe). Given the high degree of diversity seen within the class, it is possible that all three mechanisms are at work. PISN models can be self- consistently simulated from the main sequence phase of very massive stars (VMS) through to their explosion. These models robustly predict large amounts of radioactive nickel and thus very luminous SN events. However, PISN model LCs evolve more slowly than even the slowest evolving SLSNe. Multidimensional effects on the ejecta structure, specifically the mixing of radioactive nickel out to large radii, could alleviate this discrepancy with observation. Here we explore the multidimensional effects on the LC evolution by simulating the explosion phase in 1D, 2D, and 3D. We find that the ejecta from the multidimensional simulations have slightly shallower abundance gradients due to mixing at shell boundaries. We compute synthetic LCs whose shapes show no discernible differences due to the multidimensional effects.