Hostname: page-component-848d4c4894-sjtt6 Total loading time: 0 Render date: 2024-06-22T11:17:35.106Z Has data issue: false hasContentIssue false

On the Genetic Relation Between Interstellar Clouds and Dust Clouds

Published online by Cambridge University Press:  14 August 2015

Frank H. Shu*
Affiliation:
State University of New York at Stony Brook, N. Y., U.S.A.

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.

We propose that many of the denser dust clouds represent transient stages between the initiation of gravitational collapse of ordinary interstellar clouds by passage through a spiral galactic shock and the appearance of a stellar association. The interstellar gas is not processed at too rapid a rate (1) because the time spent between galactic shocks is appreciably longer than the free-fall collapse time of a typical dust cloud, and (2) because only a small fraction of the total mass of gas of a given collapsing cloud is converted into stars – the rest is presumably redispersed by various dynamical processes which accompany the formation of massive stars. We note that the residue of atomic hydrogen observed to exist in dark dust clouds is compatible with the interpretation that they are transient objects whose lifetimes are not longer than ~ 107 yr.

Type
Part V Distribution of Dust and Gas
Copyright
Copyright © Reidel 1973 

References

Hollenbach, D. J., Werner, M. W., and Salpeter, E. E.: 1971, Astrophys. J. 163, 165.Google Scholar
Hughes, M. P., Thompson, A. R., and Colvin, R. S.: 1971, Astrophys. J. Suppl. 23, 323.Google Scholar
Knapp, G. R.: 1972, unpublished , .Google Scholar
Lillie, C. F. and Witt, A. N.: 1973, this volume, p. 115.CrossRefGoogle Scholar
Lynds, B. T.: 1962, Astrophys. J. Suppl. 7, 1.Google Scholar
Lynds, B. T.: 1970, in Becker, W. and Contopoulos, G. (eds.), ‘The Spiral Structure of Our Galaxy’, IAU Symp. 38, 26.Google Scholar
Lynds, B. T.: 1972, in Evans, D. E. (ed.), ‘External Galaxies and Quasi-Stellar Objects’, IAU Symp. 44, 56.Google Scholar
Menon, T. K.: 1962, Astrophys. J. 135, 394.CrossRefGoogle Scholar
Raimond, E.: 1965, Bull. Astron. Inst. Neth. 18, 191.Google Scholar
Roberts, W. W.: 1969, Astrophys. J. 158, 123.Google Scholar
Shu, F. H., Milione, V., Gebel, W., Yuan, C., Goldsmith, D. W., and Roberts, W. W.: 1972, Astrophys. J. 173, 557.Google Scholar
Solomon, P. M. and Werner, M. W.: 1971 Astrophys. J. 165, 41.CrossRefGoogle Scholar
Witt, A. N.: 1973, this volume, p. 53.Google Scholar