Finding the First Cosmic Explosions. IV. 90 - 140 M$_{\odot}$ Pair-Instability Supernovae

TL;DR

This paper explores the potential for observing pair-instability supernovae from 90-140 solar mass Population III stars, which are more common than previously thought, using numerical simulations and upcoming telescopes.

Contribution

It presents new simulations of lower-mass pair-instability supernovae and discusses their observability, expanding understanding of early universe stellar explosions.

Findings

Supernovae from 90-140 M$_{ ext{sun}}$ stars are detectable at high redshifts.

These supernovae can be distinguished from more massive ones by their light curves.

They provide insights into first galaxy stellar populations and cosmic star formation.

Abstract

Population III stars that die as pair-instability supernovae are usually thought to fall in the mass range of 140 - 260 M$_{\odot}$. But several lines of work have now shown that rotation can build up the He cores needed to encounter the pair instability at stellar masses as low as 90 $_{\odot}$. Depending on the slope of the initial mass function of Population III stars, there could be 4 - 5 times as many stars from 90 - 140 $_{\odot}$ in the primordial universe than in the usually accepted range. We present numerical simulations of the pair-instability explosions of such stars performed with the MESA, FLASH and RAGE codes. We find that they will be visible to supernova factories such as Pan-STARRS and LSST in the optical out to z $\sim$ 1 - 2 and to JWST and the 30 m-class telescopes in the NIR out to $z \sim$ 7 - 10. Such explosions will thus probe the stellar populations of the first galaxies and cosmic star formation rates in the era of cosmological reionization. These supernovae are also easily distinguished from more massive pair-instability explosions, underscoring the fact that there is far greater variety to the light curves of these events than previously understood.