The Final Fates of Accreting Supermassive Stars

Understand

The formation of supermassive stars (SMSs) via rapid mass accretion and their direct collapse into black holes (BHs) is a promising pathway for sowing seeds of supermassive BHs in the early universe.

• We calculate the evolution of rapidly accreting SMSs by solving the stellar structure equations including nuclear burning as well as general relativistic (GR) effects up to the onset of the collapse.
• We find that such SMSs have less concentrated structure than fully-convective counterpart, which is often postulated for non-accreting ones.
• This effect stabilizes the stars against GR instability even above the classical upper mass limit $\gtrsim 10^5~M_\odot$ derived for the fully-convective stars.