TY - GEN
T1 - Supermassive black hole formation by the cold accretion shocks in the first galaxies
AU - Inayoshi, K.
AU - Omukai, K.
PY - 2012/12/1
Y1 - 2012/12/1
N2 - We propose a new scenario for supermassive star (SMS; ≳10 5M⊙) formation in shocked regions of colliding cold accretion flows near the centers of first galaxies. When the post-shock density is high enough for collisionally exciting H2 rovibrational levels (≳104cm-3), enhanced H2 collisional dissociation suppresses the gas to cool below 8000 K. In this case, the layer fragments into massive clouds (≳105M⊙), which collapse isothermally (∼ 8000 K) by the Lyα cooling without subsequent fragmentation. As an outcome, SMSs are expected to form and evolve eventually to seeds of supermassive black holes. By calculating thermal evolution of the shocked gas, we delimit the range of post-shock conditions for the SMS formation. We also find that metal enrichment does not affect the SMS forming condition for ≲10-3Z⊙ if metals are in the gas phase.
AB - We propose a new scenario for supermassive star (SMS; ≳10 5M⊙) formation in shocked regions of colliding cold accretion flows near the centers of first galaxies. When the post-shock density is high enough for collisionally exciting H2 rovibrational levels (≳104cm-3), enhanced H2 collisional dissociation suppresses the gas to cool below 8000 K. In this case, the layer fragments into massive clouds (≳105M⊙), which collapse isothermally (∼ 8000 K) by the Lyα cooling without subsequent fragmentation. As an outcome, SMSs are expected to form and evolve eventually to seeds of supermassive black holes. By calculating thermal evolution of the shocked gas, we delimit the range of post-shock conditions for the SMS formation. We also find that metal enrichment does not affect the SMS forming condition for ≲10-3Z⊙ if metals are in the gas phase.
KW - Pop III stars
KW - first galaxies
KW - supermassive black holes
UR - http://www.scopus.com/inward/record.url?scp=84875538217&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84875538217&partnerID=8YFLogxK
U2 - 10.1063/1.4754373
DO - 10.1063/1.4754373
M3 - Conference contribution
AN - SCOPUS:84875538217
SN - 9780735410923
T3 - AIP Conference Proceedings
SP - 309
EP - 312
BT - First Stars IV - From Hayashi to the Future -
T2 - 1st Stars IV: From Hayashi to the Future
Y2 - 21 May 2012 through 25 May 2012
ER -