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Star Formation Driven by Thermal-Chemical Instability in a Pre-Galactic Gas Cloud

Published online by Cambridge University Press:  04 August 2017

Yutaka Sabano
Affiliation:
Astronomical Institute, Faculty of Science, Tohoku University, Sendai, Japan
Makoto Tosa
Affiliation:
Astronomical Institute, Faculty of Science, Tohoku University, Sendai, Japan

Extract

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The hydrogen molecule would work as an efficient coolant in a pre-galactic medium which is free from heavy elements. It is shown by linear perturbation analysis that molecular reactions lead to a thermal instability of condensation mode (Sabano and Yoshii 1977, Yoshii and Sabano 1979, Silk 1983). In the present paper we study the nonlinear growth of perturbations by a one-dimensional simulation of gas dynamics, which includes molecular reactions as well as an energy equation. We numerically follow the time-evolution of a spherically symmetric perturbation, which is superposed on initially uniform medium under free-fall contraction, by a Lagrangian hydrodynamical programme with an artificial viscosity (Richtmyer and Morton 1967).

Type
I. Star Forming Processes in the Solar Neighborhood
Copyright
Copyright © Reidel 1987 

References

Richtmyer, R.D., and Morton, K.W.: 1967, Difference Methods for Initial-Value Problems, 2nd ed., Interscience Publ., New York, Ch. 12.Google Scholar
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Silk, J.: 1983, Monthly Notices Roy. Astron. Soc. 205, 705.CrossRefGoogle Scholar
Yoshii, Y., and Sabano, Y.: 1979, Publ. Astron. Soc. Japan 31, 505.Google Scholar