Can very massive stars avoid Pair-instability Supernovae?

TL;DR

This study investigates whether very massive primordial stars can avoid pair-instability supernovae by examining the effects of rotation, magnetic fields, and anisotropic mass loss, finding that certain conditions can prevent such explosions.

Contribution

It introduces a model showing that rotation, magnetic fields, and anisotropic winds can enable very massive Population III stars to evade pair-instability supernovae.

Findings

A 150 solar mass Population III star with specific rotation and magnetic conditions avoids pair instability.

Magnetic fields and wind anisotropy significantly influence core mass and stability.

The results suggest some primordial stars may not produce pair-instability supernovae, explaining observational absence.

Abstract

Very massive primordial stars ($140 M_{\odot} < M < 260 M_{\odot}$) are supposed to end their lives as pair-instability supernovae. Such an event can be traced by a typical chemical signature in low metallicity stars, but at the present time, this signature is lacking in the extremely metal-poor stars we are able to observe. Does it mean that those very massive objects did not form, contrarily to the primordial star formation scenarios? Could they avoid this tragical fate? We explore the effects of rotation, anisotropic mass loss and magnetic fields on the core size of a very massive Population III model, in order to check if its mass is sufficiently modified to prevent the pair instability. We obtain that a Population III model of $150 M_{\odot}$ with $\upsilon/\upsilon_{\rm crit}=0.56$ computed with the inclusion of wind anisotropy and Tayler-Spruit dynamo avoids the pair instability explosion.