Fast evolving pair-instability supernova models: evolution, explosion, light curves

TL;DR

This study re-examines pair-instability supernova models using advanced simulations, revealing high-mass, high-metallicity progenitors can produce fast-evolving Type I PISNe that may explain some superluminous supernovae.

Contribution

It introduces updated PISN models with detailed progenitor evolution, explosion simulations, and light curve analysis, challenging previous assumptions about PISN incompatibility with SLSNe.

Findings

High-mass, high-metallicity models produce faster PISNe.

Some PISNe can match observed SLSNe light curves.

Uncertainties in modeling affect light curve predictions.

Abstract

With an increasing number of superluminous supernovae (SLSNe) discovered the question of their origin remains open and causes heated debates in the supernova community. Currently, there are three proposed mechanisms for SLSNe: (1) pair-instability supernovae (PISN), (2) magnetar-driven supernovae, and (3) models in which the supernova ejecta interacts with a circumstellar material ejected before the explosion. Based on current observations of SLSNe, the PISN origin has been disfavoured for a number of reasons. Many PISN models provide overly broad light curves and too reddened spectra, because of massive ejecta and a high amount of nickel. In the current study we re-examine PISN properties using progenitor models computed with the GENEC code. We calculate supernova explosions with FLASH and light curve evolution with the radiation hydrodynamics code STELLA. We find that high-mass models (200 and 250 solar masses) at relatively high metallicity (Z=0.001) do not retain hydrogen in the outer layers and produce relatively fast evolving PISNe Type I and might be suitable to explain some SLSNe. We also investigate uncertainties in light curve modelling due to codes, opacities, the nickel-bubble effect and progenitor structure and composition.