Formation of the First Supermassive Black Holes

Abstract

Understanding the emergence of the first supermassive black holes, and hence the first quasars, is a crucial ingredient for models of reionization and galaxy formation. I review recent progress in simulating their formation out of primordial, pure hydrogen-helium gas at redshifts ~ 10. The predicted host systems are early dwarf galaxies with total masses ~ 10⁸ M_⊙. To be able to form seed black holes, with typical mass ~ 10⁶M_⊙, the dwarf galaxy must have avoided previous or concurrent episodes of star formation. The associated feedback effects would otherwise have prevented the effective assembly of gas in the center of the halo potential well. Such a comprehensive suppression of star formation could have been accomplished in rare cosmic environments where a strong UV background had photodissociated any molecular hydrogen which is the only viable coolant in metal-free gas.