Supermassive Black Hole Accretion and Growth

The formation, accretion and growth of supermassive black holes in the early universe are investigated. The accretion rate ${\dot M}$ is calculated using the Bondi accretion rate onto black holes. Starting with initial seed black holes with masses $M_{\rm BH}\sim 10^2-10^3M_{\odot}$, the Bondi accretion rate can evolve into a supermassive black hole with masses $M_{\rm BH}\sim 10^9-10^{10}M_{\odot}$ and with a young quasar lifetime $\sim 10^5-10^6$ years by super-Eddington accretion.