We study the thermal evolution of star-forming clouds in the primordial halos at , considering the effect of the cosmic microwave background (CMB). The CMB inhibits the formation of H2 via the photodissociation of H-, resulting in a higher temperature than in the standard evolution of the first stars at . At , the cloud evolves almost isothermally at high temperature, and supermassive stars () are formed by direct collapse.
和 英 