Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-12T12:30:09.276Z Has data issue: false hasContentIssue false
  • English
  • Français

Some Salient Features of Evolving Models of Interstellar Clouds

Published online by Cambridge University Press:  14 August 2015

S. P. Tarafdar ,
S. K. Ghosh ,
K. R. Heere  and
S. S. Prasad
S. P. Tarafdar
Affiliation:
Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Bombay 400005, India
S. K. Ghosh
Affiliation:
Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Bombay 400005, India
K. R. Heere
Affiliation:
Science Applications International Corporation, Los Altos, California, USA
S. S. Prasad
Affiliation:
Space Science Center, University of Southern California, University Park, Los Angeles, CA, USA

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Difficulties faced by various models of interstellar clouds have been discussed. A new evolutionary model which uses energy equation instead of empirical temperature-density relation used in earlier models has been presented. This calculation shows that for a given initial density, the collapsing cloud has a minimum mass which is significantly smaller than the Jean's mass. The clouds with larger mass than the critical mass continue collapsing and physical and chemical evolution remain similar to earlier evolving models. Clouds with mass smaller than the critical mass initially collapse but ultimately bounce back, producing physically similar clouds in collapsing and expanding phases. The chemical evolution in these two physically similar clouds is different mainly due to differences in their lifetime. The lifetime of this oscillating cloud is also longer than the collapsing cloud.

Type
Joint Discussions
Information
Highlights of Astronomy , Volume 8: Highlights of Astronomy. As presented at the XXth General Assembly of the IAU, 1988 , 1989 , pp. 345 - 355
Copyright
Copyright © Kluwer 1989

References

Black, J. H. (1987) in Vardya, M. S. and Tarafdar, S. P. (eds.), IAU Symposium 120, Astrochemistry, Reidel, Dordrecht, p. 217.Google Scholar
Black, J. H. (1988) Highlights of Astronomy, vol. 8, p.Google Scholar
Boland, W. and de Jong, T. (1982) Ap. J. 261, 110.Google Scholar
Boland, W. and de Jong, T. (1984) Astr. Ap. 134, 87.Google Scholar
Dalgarno, A. (1987a) in Morfill, G. and Scholer, M. S. (eds.), Physical Processes in Interstellar Clouds, Reidel, Dordrecht, p.219.Google Scholar
Dalgarno, A. (1987b) in Kingston, A. E. (ed.), Recent Studies in Atomic and Molecular Processes, Plenum Press London, p. 51.Google Scholar
De Jong, T, Dalgarno, A. and Boland, W. (1980) Astr. Ap. 91, 68.Google Scholar
D’Hendecourt, L. B., Allamandola, L. J., Baas, F. and Greenberg, J. M. (1982) Astr. Ap. 109, L12.Google Scholar
Gerola, H. and Gllassgold, A. E. (1978) Ap. J. Suppl. 37, 1.CrossRefGoogle Scholar
Graedel, T. E., Langer, W. D.and Frerking, M. A. (1982) Ap. J. Suppl. 48, p. 321.CrossRefGoogle Scholar
Hallenback, D. J.and Salpeter, E. E. 1970, J. Chem. Phys. 53, p. 79.Google Scholar
Hartquist, T. W. (1987), in Vardya, M. S. and Tarafdar, S. P. (eds.), IAU Symposium 120, Astrochemistry, Reidel, Dordrecht, p. 297.Google Scholar
Herbst, E. (1987) in Vardya, M. S. and Tarafdar, S. P. (eds.), IAU Symposium 120, Astrochemistry, Reidel, Dordrecht, p. 235.Google Scholar
Herbst, E. and Leung, C. M. (1986a) M.N.R.A.S. 222, 689.Google Scholar
Herbst, E. and Leung, C. M. (1986b), Ap. J. 310, 378.Google Scholar
Irvine, W. M., Goldsmith, P. F.and Hjalmarson, A. (1987) in Hollenbach, D.J. and Thronson, H. A. Jr. (eds). Interstellar Processes, Reidel, Dordrecht), p. 561.Google Scholar
Langer, W. D.and Graedel, T. E. (1987), in Vardya, M. S. and Tarafdar, S. P. (eds.), IAU Symposium 120, Astrochemistry, Reidel, Dordrecht), p. 305.CrossRefGoogle Scholar
Leger, A., Jura, M. and Omont, A. (1985) Astr Ap. 144, 147.Google Scholar
Millar, T. J. (1988) Highlights of Astronomy, Vol. 8, p.Google Scholar
Millar, T. J.and Freeman, A. (1984), M.N.R.A.S. 207, 405; 425.CrossRefGoogle Scholar
Millar, T. J.and Nejad, L. A. M. (1985) M.N.R.A.S. 217, 507.CrossRefGoogle Scholar
Prasad, S. S. (1987) in Vardya, M. S. and Tarafdar, S. P. (eds). IAU Symposium 120, Astrochemistry, Reidel, Dordrecht), p. 259.Google Scholar
Prasad, S. S.and Huntress, W. T. (1980) Ap. J. Suppl. 43, 1.Google Scholar
Prasad, S. S., Tarafdar, S. P. Villere, K. R.and Huntress, W. T. Jr. (1987), in Hollenbach, D. J. and Thronson, H. A. Jr. (eds.), Interstellar Processes, Reidel, Dordrecht), p. 631.Google Scholar
Suzuki, H. (1983) Ap. J. 272, 579.CrossRefGoogle Scholar
Tarafdar, S. P., Prasad, S. S., Huntress, W. T. Villere, K. R.and Black, D. C. (1985) Ap. J. 289, 220.Google Scholar
van Dishoeck, E. F. (1988a), in Millar, T. J. and Williams, D. A. (eds.), Reaction Rate Coefficients in Astrophysics, (in press).Google Scholar
Dishoeck, van (1988b) Highlights of Astronomy, vol. 8, p.Google Scholar
van Dishoeck, E. F.and Black, J. H. (1986) Ap. J. Suppl. 62, 109.Google Scholar
Viala, Y. P. (1986) Astr. Ap. Suppl. 64, 391 Google Scholar
Viala, Y. P., Roueff, E. and Abgrall, H. 1987, Astr. Ap. Watt, G. D. (1983) M.N.R.A.S. 205, 321.Google Scholar
Williams, D.A. and Hartquist, T. W. (1984) M.N.R.A.S. 210, 141.Google Scholar
Winnewisser, G. and Herbst, E. (1987).Topics in Current Chemistry 139, 121.Google Scholar
Wootten, A. (1987) in Vardya, M. S. and Tarafdar, S. P. (eds.), IAU Symposium 120, Astrochemistry, Reidel, Dordrecht, p.311.Google Scholar