Theoretical Astrophysics Colloquia

50th Colloquium

IMF transition across various environments in the early universe

Ito Mana

Tohoku University


Abstract
We study the thermal evolution of star-forming clouds in the primordial halos at $z>100$, 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 $z<100$. At $z>500$, the cloud evolves almost isothermally at high temperature, and supermassive stars ($\sim 10^5 M_\odot$) are formed by direct collapse.


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