The Maximum Mass of Population III Stars (The Earliest Stars)

THE MASS OF THE FIRST STARS

Author:

1. Hajime Susa (a)

Affiliation:

a. Department of Physics, Konan University, Okamoto, Kobe, Japan

Abstract:

We perform a three-dimensional radiation hydrodynamics simulation to investigate the formation of the first stars from the initial collapse of a primordial gas cloud to the formation and growth of protostars. The simulation is integrated until ~0.1 Myr after the formation of the primary protostar, by which time the protostars have already settled onto the main sequence. This work represents the first attempt at simulating the first episodes of star formation, taking into account the ultraviolet radiative feedback effect from multiple protostars as well as the three-dimensional effects of the fragmentation of the accretion disk. We find that the mass accretion onto Population III protostars is significantly suppressed by their radiative feedback. As a result, we find five stars formed in this particular simulation. The final masses of the stars are less than 60 M ☉, including a star of 4.4 M ☉. Formation of such a star hints at the existence of even lower-mass stars that would live today.