Dr. Kohei Inayoshi (Columbia)

University of Florida Astronomy Colloquium - Feb. 11th, 2015

Formation of supermassive black hole seeds in first galaxies

Recent observations reveal the existence of supermassive black holes (SMBH) with > 10^9 Msun in the early universe with redshift z>7. The existence of high-z SMBHs puts strong constraints on the origins and formation pathways of SMBHs because the time required to form such massive objects from stellar-mass seed BHs becomes longer than the Hubble time at z>7. As a solution for this problem, formation of massive seed BHs via the collapse of supermassive stars (SMSs; >10-5 Msun) has been invoked. I will discuss our recent works about the necessary condition to form SMSs and gravitational collapse of a massive primordial cloud in the first galaxy.