The effects of convection criteria on the evolution of population III stars and the detectability of their supernovae

TL;DR

This study models Population III star evolution and their supernovae, highlighting how convection criteria influence outcomes and estimating the observability of these early cosmic explosions.

Contribution

It provides detailed evolution models for Pop III stars using different convection criteria and links these models to supernova observability predictions.

Findings

Evolution is highly sensitive to convection criterion choice.

The 40 M$_\odot$ Schwarzschild model yields the brightest supernova peak.

At redshift z=15, the 60 M$_\odot$ model's brightness rivals the 40 M$_\odot$ model.

Abstract

The first stars continue to elude modern telescopes, but much has been accomplished in observing the glow of the first galaxies. As detection capabilities improve we will eventually resolve these galaxies, but hopes of observing an individual star remains dim for the foreseeable future. However, our first view of an individual first star may be possible due to its explosion. In this work, we present evolution calculations for Population III (Pop III) stars and their subsequent supernovae explosions. Our evolution models include a mass range of 15 - 100 M$_\odot$, each with initial heavy element abundance Z = 10-14. Our models are evolved from pre-main sequence through formation of an iron core, and thus near to core collapse. We find that modelling the evolution of these stars is very sensitive to the choice of convection criterion; here we provide evolution results using both the Schwarzschild and Ledoux criteria. We also use the final structure from our models for numerical simulation of their supernovae light curves using a radiation hydrodynamics code. In doing so, we estimate a lower bound of initial model mass that may be possible to observe in the near future. We also find that our 40 M$_\odot$ Schwarzschild evolution model produces the brightest supernova peak and statistically should be the most frequently observed. At our highest redshift z= 15, only the 60 M$_\odot$ Schwarzschild model at peak magnitude starts to rival the 40 M$_\odot$ model in brightness.