Studying the Effect of Radiation Pressure on Evolution of a Population III Stellar Cluster

Abstract Recent numerical simulations have shown that the unstable disk within the central regime of the primordial gas cloud fragments to form multiple protostars on several scales. Their evolution depends on the mass accretion phenomenon, interaction with the surrounding medium and radiative feedback respectively. In this work, we use a fast semianalytical framework in order to model multiple protostars within a rotating cloud, where the mass accretion is estimated via a Bondi–Hoyle flow and the feedback process is approximated through radiation pressure. We observe that while some of the evolving protostars possibly grow massive (≈1–75 M ⊙ ) via accretion and mergers, a fraction of them (≈20%) are likely to be ejected from the parent cloud with a mass corresponding to M * ≲ 0.8 M ⊙ . These low-mass protostars may be considered as the potential candidates to enter the zero-age-main-sequence phase and possibly survive until the present epoch.