The mass of first stars

Abstract

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