論文

査読有り
2017年3月

Do stellar winds prevent the formation of supermassive stars by accretion?

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
  • Daisuke Nakauchi
  • ,
  • Takashi Hosokawa
  • ,
  • Kazuyuki Omukai
  • ,
  • Hideyuki Saio
  • ,
  • Ken'ichi Nomoto

465
4
開始ページ
5016
終了ページ
5025
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1093/mnras/stw3114
出版者・発行元
OXFORD UNIV PRESS

Supermassive stars (SMSs; similar to 10(5)M(circle dot)) formed from metal-free gas in the early Universe attract attention as progenitors of supermassive black holes observed at high redshifts. To form SMSs by accretion, central protostars must accrete at as high rates as similar to 0.1-1M(circle dot)yr(-1). Such protostars have very extended structures with bloated envelopes, like supergiant stars, and are called supergiant protostars (SGPSs). Under the assumption of hydrostatic equilibrium, SGPSs have density-inverted layers, where the luminosity becomes locally super-Eddington, near the surface. If the envelope matter is allowed to flow out, however, a stellar wind could be launched and hinder the accretion growth of SGPSs before reaching the supermassive regime. We examine whether radiation-driven winds are launched from SGPSs by constructing steady and spherically symmetric wind solutions. We find that the wind velocity does not reach the escape velocity in any case considered. This is because once the temperature falls below similar to 10(4) K, the opacity plummet drastically owing to the recombination of hydrogen and the acceleration ceases suddenly. This indicates that, in realistic non-steady cases, even if outflows are launched from the surface of SGPSs, they would fall back again. Such a 'wind' does not result in net mass-loss and does not prevent the growth of SGPSs. In conclusion, SGPSs will grow to SMSs and eventually collapse to massive black holes of similar to 10(5)M(circle dot), as long as the rapid accretion is maintained.

Web of Science ® 被引用回数 : 6

リンク情報
DOI
https://doi.org/10.1093/mnras/stw3114
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000395170200091&DestApp=WOS_CPL
URL
http://orcid.org/0000-0003-3127-5982