Protostellar Feedback Halts the Growth of the First Stars in the Universe

TL;DR

This study uses radiation-hydrodynamics simulations to show that protostellar radiation halts the growth of the first stars at around 43 solar masses, influencing early universe evolution.

Contribution

It provides the first detailed simulation demonstrating how protostellar feedback limits the mass of primordial stars, challenging previous assumptions of extremely massive first stars.

Findings

Protostellar radiation evaporates the accretion disk at 43 solar masses.

Massive primordial stars may be less than previously thought.

These stars' masses could explain the absence of pair-instability supernova signatures.

Abstract

The first stars fundamentally transformed the early universe by emitting the first light and by producing the first heavy elements. These effects were predetermined by the mass distribution of the first stars, which is thought to have been fixed by a complex interplay of gas accretion and protostellar radiation. We performed radiation-hydrodynamics simulations that followed the growth of a primordial protostar through to the early stages as a star with thermo-nuclear burning. The circumstellar accretion disk was evaporated by ultraviolet radiation from the star when its mass was 43 times that of the Sun. Such massive primordial stars, in contrast to the often postulated extremely massive stars, may help explain the fact that there are no signatures of the pair-instability supernovae in abundance patterns of metal-poor stars in our galaxy.