Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-30T07:42:17.876Z Has data issue: false hasContentIssue false

The Dynamical Evolution of Clusters of Galaxies

Published online by Cambridge University Press:  30 March 2016

Simon D.M. White*
Affiliation:
Institute of Astronomy, Cambridge, England

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.

Typical orbital periods for galaxies in rich clusters are observed to be several billion years. Consequently these large systems have had little time to come to equilibrium, and indeed if they formed from small initial density perturbations they must have taken a substantial fraction of the age of the Universe to separate from the Hubble flow and recollapse (Gunn and Gott 1972). Despite the relatively short time available, dynamical effects can cause appreciable evolution both in the distribution of galaxies within clusters and in the observable features of individual galaxies. The overall aspect of a cluster changes as violent relaxation irons out in homogeneities and establishes a relaxed core-halo structure. At the same time collisional relaxation causes massive galaxies to lose energy to lighter objects in an attempt to reach equipartition of kinetic energy, and to spiral towards the cluster centre. These processes are relatively easy to analyse in any particular scheme for cluster formation, and below we concentrate on comparing their predicted effects with observation.

Type
Joint Dicussions
Copyright
Copyright © Reidel 1977

References

Aarseth, S. J. and Lecar, M.: 1975, Ann. Rev. Astvon. Astvophys. 13, 1.Google Scholar
Austin, T. B. and Peach, J. V.: 1974, Mon. Not. Roy. astr. Soc. 168, 591.Google Scholar
Bahcall, N. A.: 1973, Astrophys. J. 183, 783.CrossRefGoogle Scholar
Biermann, C. and Silk, J.: 1976, Astron. and Astrophys. 48, 287.Google Scholar
Biermann, C.: 1976, Astron. and Astrophy. 48, 295.Google Scholar
Chandrasekhar, S.: 1942, Prinoiples of Stellar Dynamics, Dover, New York.Google Scholar
Gallagher, J. S. and Ostriker, J. P.: 1972, Astronom. J. 77, 288.Google Scholar
Gregory, S. A. and Tifft, W. G.: 1976, Astrophys. J. 205, 716.CrossRefGoogle Scholar
Gunn, J. E. and Gott, J. R.: 1972, Astrophys. J. 176, 1.Google Scholar
Oemler, A.: 1973, Astrophys. J. 180, 11.Google Scholar
Oemler, A.: 1974, Astrophys. J. 194, 1.CrossRefGoogle Scholar
Ostriker, J. P. and Tremaine, S. D.: 1975, Astrophys. J. 202, L113.Google Scholar
Peebles, P. J. E.: 1970, Astronom. J. 75, 13.CrossRefGoogle Scholar
Peebles, P. J. E.: 1971, Physical Cosmology, Princeton Univ. Press, Prinaeton.Google Scholar
Richstone, D. O.: 1976, Astrophys. J. 204, 642.Google Scholar
Rood, H. J., Page, T. L., Kintner, E. C. and King, I. R.: 1972, Astrophys. J., 175, 627.Google Scholar
Spitzer, L. and Baade, W.: 1951, Astrophys. J., 113, 413.Google Scholar
Tartar, J. and Silk, J.: 1974, Quart. J. Roy. astr. Soc. 15, 122.Google Scholar
White, S. D. M.: 1976a, Mon. Not. Roy. astr. Soc. 174, 19.CrossRefGoogle Scholar
White, S. D. M.: 1976b, Mon. Not. Roy. astr. Soc. in press.Google Scholar
White, S. D. M.: 1976c, Mon. Not. Roy. astr. Soc. in press.Google Scholar