Hostname: page-component-848d4c4894-wg55d Total loading time: 0 Render date: 2024-05-19T01:35:07.478Z Has data issue: false hasContentIssue false
  • English
  • Français

Theoretical Processes in Star Formation

Published online by Cambridge University Press:  14 August 2015

L. Mestel
L. Mestel*
Affiliation:
Astronomy Centre, University of Sussex

Extract

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.

To bring out the basic problem of star formation, consider a non-rotating cosmical gas cloud which is free to contract and so to convert most of its gravitational energy into kinetic energy of mass motion. Fluid dynamical systems in general tend to dissipate their kinetic energy, and a diffuse gas cloud easily radiates excess heat. If the cloud did not break up into fragments, then the steady conversion of gravitational energy into radiation would lead ultimately into the formation of a compact massive body - perhaps a quasar - but not of a star cluster, which is maintained at a comparatively low mean density by random stellar kinetic energy. Thus the transition from a gravitationally-bound cloud of gas and dust into a bound star cluster - or a fortiori into an expanding O-B association - requires that gravitational energy released during collapse be conserved as the random macroscopic kinetic energy. It is very likely that star formation is often triggered by processes that are essentially dissipative, such as shocks following passage of the spiral wave, or cloud-cloud collisions; however, it is equally important to emphasise that we require at some stage a cut-off in kinetic energy dissipation. And indeed, once a cloud has been able to fragment into a group of self-gravitating blobs, each of small geometrical cross-section, the chance of inelastic collisions between blobs is sharply reduced.

Type
Research Article
Information
Symposium - International Astronomical Union , Volume 75: Star Formation , 1977 , pp. 213 - 232
Copyright
Copyright © Reidel 1977 

References

Arny, T. and Weissman, P. 1973, Astronom. J. 78, 309.CrossRefGoogle Scholar
Bisnovatyi-Kogan, G.S., Ruzmaikin, A.A. and Sunyaev, R.A. 1973, Astron. J. USSR 50, 210.Google Scholar
Bodenheimer, P. 1976, (private communication).Google Scholar
Bonnor, W.B. 1956, Mon. Not. R. Astr. Soc. 116, 351.Google Scholar
Cameron, A.G.W. 1962, Icarus 1, 13.Google Scholar
Cameron, A.G.W. 1972, in On the Origin of the Solar System, ed. Reeves, H. (C.N.R.S., Paris).Google Scholar
Chandrasekhar, S. and Fermi, E. 1953, Astrophys. J. 118, 116.CrossRefGoogle Scholar
Ebert, R. 1955, Z. f. Astrophys. 37, 217.Google Scholar
Ebert, R. 1964, Habilitationschrift, Un. Frankfurt-am-Main.Google Scholar
Ebert, R., von Hoerner, S. and Temesvary, S. 1960, Die Entstehung von Sternen (Springer-Verlag, Berlin).Google Scholar
Garlick, A.R. 1976, (preprint).Google Scholar
Gaustad, J.E. 1963, Astrophys. J. 138, 1050.CrossRefGoogle Scholar
Gillis, J., Mestel, L. and Paris, R.B. 1974, Astrophys. Sp. Sci. 27, 167.Google Scholar
Gillis, J., Mestel, L. and Paris, R.B. 1976 (in preparation).Google Scholar
Gold, T. 1972, High Energy Activity During the Late Phases of Stellar Evolution, Accademia dei Lincei, Rome.Google Scholar
Gold, T. 1974, Phil. Trans. R. Soc. Lond. A, 277, 453.Google Scholar
Hayakawa, S., Nishimura, S. and Takayanagi, K. 1961, Pub. Astr. Soc. Japan 13, 184.Google Scholar
Hoyle, F. 1953, Astrophys. J. 118, 513.Google Scholar
Hunter, C. 1962, Astrophys. J. 135, 594.Google Scholar
Hunter, C. 1963, Mon. Not. R. Astr. Soc. 126, 299.Google Scholar
Hunter, C. 1964, Astrophys. J. 139, 570.Google Scholar
Hutchins, J.B. 1976, Astrophys. J. 205, 103.Google Scholar
Kulsrud, R.M. 1971, Astrophys. J. 163, 567.Google Scholar
Layzer, D. 1963, Astrophys. J. 137, 351.Google Scholar
Levine, R.H. 1974, Astrophys. J. 190, 457.Google Scholar
Lin, C.C., Mestel, L. and Shu, F.H. 1965, Astrophys. J. 142, 1431.Google Scholar
Low, C. and Lynden-Bell, D. 1976, Mon. Not. R. Astr. Soc. 176, 367.CrossRefGoogle Scholar
Lynden-Bell, D. 1973, in Contopoulos, G., Hénon, M., Lynden-Bell, D., Dynamical Structure and Evolution of Stellar Systems, Saas-Fee Lectures.Google Scholar
Lynden-Bell, D. and Kalnajs, A.J. 1972, Mon. Not. R. Astr. Soc. 157, 1.Google Scholar
Lynden-Bell, D. and Pringle, J.E. 1974, Mon. Not. R. Astr. Soc. 168, 603.CrossRefGoogle Scholar
McCrea, W.H. 1953, Mon. Not. R. Astr. Soc. 113, 162.Google Scholar
McCrea, W.H. 1957, Mon. Not. R. Astr. Soc. 117, 562.CrossRefGoogle Scholar
McCrea, W.H. 1960, Proc. Roy. Soc. A 256, 245.Google Scholar
Markey, P. and Tayler, R.J. 1973, Mon. Not. R. Astr. Soc. 163, 77.CrossRefGoogle Scholar
Markkanen, T. 1976 (preprint).Google Scholar
Mestel, L. 1952, Mon. Not. R. Astr. Soc. 112, 583 and 598.Google Scholar
Mestel, L. 1954, Mon. Not. R. Astr. Soc. 114, 437.CrossRefGoogle Scholar
Mestel, L. 1960, Vistas in Astronomy 3, 296.Google Scholar
Mestel, L. 1963, Mon. Not. R. Astr. Soc. 126, 553.Google Scholar
Mestel, L. 1965, Quart. J. R. Astr. Soc. 6, 161 and 265.Google Scholar
Mestel, L. 1966, Mon. Not. R. Astr. Soc. 133, 265.Google Scholar
Mestel, L. 1969, in Plasma Instabilities in Astrophysics, ed. Tidman, D.A. and Wentzel, D.G. (Gordon and Breach, New York).Google Scholar
Mestel, L. 1976, IAU Colloquium No. 32, Physics of Ap Stars, ed. Weiss, W. W. (D. Reidel, Amsterdam).Google Scholar
Mestel, L. and Paris, R.B. 1976, (in preparation).Google Scholar
Mestel, L. and Spitzer, L. Jr. 1956, Mon. Not. R. Astr. Soc. 116, 583.Google Scholar
Mestel, L. and Strittmatter, P.A. 1967, Mon. Not. R. Astr. Soc. 137, 95.Google Scholar
Mouschovias, T. Ch. 1976a, Astrophys. J. 206, 753.CrossRefGoogle Scholar
Mouschovias, T. Ch. 1976b, Astrophys. J. 207, 141.Google Scholar
Mouschovias, T. Ch. 1976c, Astrophys. J. (in press).Google Scholar
Mouschovias, T. Ch. 1976d, (in preparation).Google Scholar
Nakano, T. 1976, Publ. Astron. Soc. Japan 28, 355.Google Scholar
Nakano, T. and Tademaru, E. 1972, Astrophys. J. 173, 87.Google Scholar
Oppenheimer, M. and Dalgarno, A. 1974, Astrophys. J. 192, 29.CrossRefGoogle Scholar
Paris, R.B. 1971, , Manchester University.Google Scholar
Parker, D.A. 1973, Mon. Not. R. Astr. Soc. 163, 41.CrossRefGoogle Scholar
Parker, D.A. 1974, Mon. Not. R. Astr. Soc. 168, 331.Google Scholar
Rees, M.J. 1976, Mon. Not. R. Astr. Soc. 176, 483.Google Scholar
Ruzmaikina, T.V. and Safronov, V.S. 1976, Astron. J.USSR. 53, 860.Google Scholar
Silk, J. 1976a,b, Astrophys. J. (in press).Google Scholar
Smith, R.C. and Wright, A.E. 1975, Mon. Not. R. Astr. Soc. 172, 221.Google Scholar
Spitzer, L. Jr. 1963, in Origin of the Solar System, ed. Jastrow, R. and Cameron, A.G.W. (Academic Press, New York).Google Scholar
Spitzer, L. Jr. 1968, in Nebulae and Interstellar Matter, ed. Middlehurst, B. M. and Aller, L. H. (University of Chicago Press, Chicago).Google Scholar
Stewart, J.M. 1975, Astron. Astrophys. 42, 95.Google Scholar
Stewart, J.M. 1976, Astron. Astrophys. 49, 39.Google Scholar
Strittmatter, P.A. 1966, Mon. Not. R. Astr. Soc. 132, 359.CrossRefGoogle Scholar
ter Haar, D. 1950, Astrophys. J. 111, 179.Google Scholar
Verschuur, G.L. 1969, in Plasma Instabilities in Astrophysics, ed. Tidman, D. A. and Wentzel, D. G. (Gordon and Breach, New York).Google Scholar
von Weizsäcker, C.F. 1944, Z. f. Astrophys. 22, 319.Google Scholar
von Weizsäcker, C.F. 1947, Z. f. Astrophys. 24, 181.Google Scholar
Vrba, F.J. 1976, , Un. of Arizona.Google Scholar
Vrba, F.J., Strom, S.E. and Strom, K.M. 1976, (preprint).Google Scholar
Wright, G.A.E. 1973, Mon. Not. R. Astr. Soc. 162, 359.Google Scholar