論文

査読有り
2016年12月

COSMOLOGICAL SIMULATIONS OF EARLY BLACK HOLE FORMATION: HALO MERGERS, TIDAL DISRUPTION, AND THE CONDITIONS FOR DIRECT COLLAPSE

ASTROPHYSICAL JOURNAL
  • Sunmyon Chon
  • ,
  • Shingo Hirano
  • ,
  • Takashi Hosokawa
  • ,
  • Naoki Yoshida

832
2
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.3847/0004-637X/832/2/134
出版者・発行元
IOP PUBLISHING LTD

Gravitational collapse of a massive primordial gas cloud is thought to be a promising path for the formation of supermassive black holes in the early universe. We study conditions for the so-called direct collapse (DC) black hole formation in a fully cosmological context. We combine a semianalytic model of early galaxy formation with halo merger trees constructed from dark matter N-body simulations. We locate a total of 68 possible DC sites in a volume of 20h-1Mpcon a side. We then perform hydrodynamics simulations for 42 selected halos to study in detail the evolution of the massive clouds within them. We find only two successful cases where the gas clouds rapidly collapse to form stars. In the other cases, gravitational collapse is prevented by the tidal force exerted by a nearby massive halo, which otherwise should serve as a radiation source necessary for DC. Ram pressure stripping disturbs the cloud approaching the source. In many cases, a DC halo and its nearby light source halo merge before the onset of cloud collapse. When the DC halo is assembled through major mergers, the gas density increases rapidly to trigger gravitational instability. Based on our cosmological simulations, we conclude that the event rate of DC is an order of magnitude smaller than reported in previous studies, although the absolute rate is still poorly constrained. It is necessary to follow the dynamical evolution of a DC cloud and its nearby halo(s) in order to determine the critical radiation flux for DC.

リンク情報
DOI
https://doi.org/10.3847/0004-637X/832/2/134
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000389049800005&DestApp=WOS_CPL
URL
http://orcid.org/0000-0003-3127-5982
ID情報
  • DOI : 10.3847/0004-637X/832/2/134
  • ISSN : 0004-637X
  • eISSN : 1538-4357
  • ORCIDのPut Code : 48854055
  • Web of Science ID : WOS:000389049800005
  • BibTex Code : 2016ApJ...832..134C

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