Life and Death of Very Massive Stars

TL;DR

This paper investigates the evolution and final fate of very massive stars (150-320 solar masses), focusing on how mass loss and rotation influence whether they end as supernovae or pair-instability supernovae, with implications for early universe stellar populations.

Contribution

It provides new stellar evolution models that incorporate mass loss and rotation effects on very massive stars at different metallicities, predicting their ultimate explosive outcomes.

Findings

Most very massive stars at solar metallicity end as type Ic supernovae.

Stars with low metallicity may retain enough mass to produce pair-instability supernovae.

First stellar generations likely did not produce observable PISN signatures.

Abstract

We recently determined the mass of the most massive star known to the date, R136a1 with a mass at birth 320 times the mass of our sun, as well as the mass of several other stars that are more massive than 150 M. Such massive stars (~150-300 M) may end their life as pair-instability supernovae (PISN) if they retain enough mass until they die. We have calculated a grid of stellar evolution models in order to investigate the impact of mass loss and rotation on the evolution and fate of these very massive stars. As mass loss is very strong at solar metallicity, our models predict that most of the very massive stars will die as type Ic SNe. Only slowly and non-rotating stars at metallicities below that of the LMC might retain enough mass to produce a PISN. This would mean that the first stellar generations might have produced PISN although their chemical signature is not observed in extremely metal poor stars in the halo of our galaxy.