The extended star formation history of the first generation of stars and the reionization of cosmic hydrogen

Abstract

Population III star formation (SF) is thought to be quenched when the metallicity of the star-forming gas has reached a critical level. At high redshift, when the general intergalactic medium (IGM) was enriched with metals, the fraction of primordial gas that had already collapsed in minihalos was significantly larger than the fraction of primordial gas that had already been involved in Population III SF. We argue that this reservoir of minihalo gas remained largely in a metalfree state until these minihalos merged into large systems and formed stars. As a result, the era of Population III SF was significantly prolonged, leading to a total integrated Population III SF an order of magnitude l..