論文

査読有り
2003年4月

Criticality and convergence in Newtonian collapse

PHYSICAL REVIEW D
  • T Harada
  • ,
  • H Maeda
  • ,
  • B Semelin

67
8
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1103/PhysRevD.67.084003
出版者・発行元
AMER PHYSICAL SOC

We study through numerical simulation the spherical collapse of isothermal gas in Newtonian gravity. We observe a critical behavior which occurs at the threshold of gravitational instability leading to core formation. This was predicted in a previous work by two of the present authors. We describe it in detail in this work. For a given initial density profile, we find a critical temperature T*, which is of the same order as the virial temperature of the initial configuration. For the exact critical temperature, the collapse converges to a self-similar form, the first member in Hunter's family of self-similar solutions. For a temperature close to T*, the collapse first approaches this critical solution. Later on, in the supercritical case (T<T*), the collapse converges to another self-similar solution, which is called the Larson-Penston solution. In the subcritical case (T>T*), the gas bounces and disperses to infinity. We find two scaling laws with respect to \T-T*\: one for the collapsed mass in the supercritical case and the other, which was not predicted before, for the maximum density reached before dispersal in the subcritical case. The value of the critical exponent is measured to be similar or equal to0.11 in the supercritical case, which agrees well with the predicted value similar or equal to0.10567. These critical properties are quite similar to those observed in the collapse of a radiation fluid in general relativity. We study the response of the system to temperature fluctuation and discuss astrophysical implications for the interstellar medium structure and for the star formation process. Newtonian critical behavior is important not only because it provides a simple model for general relativity but also because it is relevant for astrophysical systems such as molecular clouds.


リンク情報
DOI
https://doi.org/10.1103/PhysRevD.67.084003
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000182728200037&DestApp=WOS_CPL
ID情報
  • DOI : 10.1103/PhysRevD.67.084003
  • ISSN : 2470-0010
  • eISSN : 2470-0029
  • Web of Science ID : WOS:000182728200037

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