event
Tuesday 26 Jan 2021: [Journal Club] Title: Evolving rapidly accreting supermassive primordial stars with MESA
Nicholas Herrington - University of Exeter
Zoom 11:15-11:45
Observations suggest that the first quasars illuminated the universe as early as 650 million years after the big bang (redshift z ~ 6-8). These monstrous objects host central supermassive black holes (SMBHs) of mass > 10^9 solar masses. The first stars in our universe are thought to have ignited relatively close in time to these quasar observations (z ~ 15-25). This leads to the question of how did the first quasars form so early on in the history of the universe? Star formation in the early universe was chaotic, the primordial soup of gas present after the big bang enables the formation of massive metal free stars. Cosmological simulations of the first halos collapsing to dense stellar objects suggest that in the presence of strong UV fluxes, a primordial halo can grow to significant masses leading to catastrophic infall to a massive central star that experiences inflow rates of up to 1 solar mass per year. A massive star subjected to these inflow rates is built up to supermassive size relatively quickly, collapsing to a massive black hole at the end of its life. Our models show the evolution from birth to death of primordial stars that are subjected to accretion rates of 0.001 – 1 solar mass per year throughout their lifetime.
