Supermassive black hole formation by the cold accretion shocks in the first galaxies

K. Inayoshi, K. Omukai

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


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.

Original languageEnglish
Title of host publicationFirst Stars IV - From Hayashi to the Future -
Number of pages4
Publication statusPublished - 2012 Dec 1
Externally publishedYes
Event1st Stars IV: From Hayashi to the Future - Kyoto, Japan
Duration: 2012 May 212012 May 25

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616


Other1st Stars IV: From Hayashi to the Future


  • Pop III stars
  • first galaxies
  • supermassive black holes

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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