The Final Fate of Supermassive $M \sim 5 \times 10^4 \; M_\odot$ Pop III Stars: Explosion or Collapse?

TL;DR

This study explores whether supermassive Population III stars around 5 x 10^4 solar masses undergo supernova explosions or collapse, using detailed simulations, and finds explosions are unlikely in non-rotating cases but possible with slow rotation.

Contribution

The paper provides the first detailed simulation-based analysis of supermassive Pop III star explosions, considering relativistic effects and rotation, challenging previous assumptions about their fate.

Findings

No explosion in non-rotating models.

Possible explosion with slow rotation.

Implications for early universe black hole formation.

Abstract

We investigate the possibility of a supernova in supermassive ($5 \times 10^4 \;M_\odot$) population III stars induced by a general relativistic instability occurring in the helium burning phase. This explosion could occur via rapid helium burning during an early contraction of the isentropic core. Such an explosion would be visible to future telescopes and could disrupt the proposed direct collapse formation channel for early universe supermassive black holes. We simulate first the stellar evolution from hydrogen burning using a 1D stellar evolution code with a post Newtonian approximation; at the point of dynamical collapse, we switch to a 1D (general relativistic) hydrodynamics code with the Misner-Sharpe metric. In opposition to a previous study, we do not find an explosion in the non rotating case, although our model is close to exploding for a similar mass to the explosion in the previous study. When we include slow rotation, we find one exploding model, and we conclude that there likely exist additional exploding models, though they may be rare.