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Merger Rates and Galaxy Formation

Published online by Cambridge University Press:  03 August 2017

Tapan K. Chatterjee
Tapan K. Chatterjee*
Affiliation:
Facultad de Ciencias, Fisico-Matematicas, Universidad A. Puebla, A.P. 1152 Puebla, MEXICO

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Observations indicate that the frequency of merging galaxies in the present epoch is ≈0.3%, and an extrapolation to past yields a frequency ≈5% (Toomre, 1977, Tremaine, 1980). Loosely bound pairs of galaxies that had separated to great distances in the general cosmic expansion and have lately fallen together again in comet-like plunging ellipses seem to be the most lucrative candidates for mergers. But could all ellipticals be merger remnants ? To study this problem we have determined the frequency of merging galaxies on the basis of the collision theory, by studying many collisions with different collision parameters and progenitor pairs (using the impulsive approximation) and compared the values so obtained with the observational ones. The mean values of the collision parameters favourable for mergers for different types of progenitor pairs are segregated from a statistical study of many collisions and are compared to the corresponding values in dense regions where a galaxy and its nearest neighbour can be visualised to form a loosely bound pair, to determine the corresponding frequencies. The theory and method is described in detail in Chatterjee, 1987, 1990, except that subsequently we have studied disk-disk mergers by using basically the same method.

Type
XI- Galaxy Evolution
Information
Symposium - International Astronomical Union , Volume 146: Dynamics of Galaxies and their Molecular Cloud Distributions , 1991 , pp. 377 - 378
Copyright
Copyright © Kluwer 1991 

References

Chatterjee, T.K., 1987 : Astrophys. Space Sci. 137, 267 CrossRefGoogle Scholar
Chatterjee, T.K., 1990 : in Sulentic, J.W. and Keel, W.C. (eds), “Paired and Interacting Galaxies”, IAU col. 124 (in press) Google Scholar
Schombert, J.M., 1987 : Astrophys. J. Suppl. 64, 643 CrossRefGoogle Scholar
Terlevich, , Davis, R., Faber, R.L., Burstein, S.M.D., 1981 : Mont. Not. Roy. Astron. Soc. 196, 381 CrossRefGoogle Scholar
Toomre, A., 1977 : in Tinsley, B.M. and Larson, R.B. (eds), “The Evolution of Galaxies and Stellar Populations”, Yale Univ. Obs. p. 401 Google Scholar
Tremaine, S.D., 1980 : in Fall, S.M. and Lynden-Bell, D. (eds.), “The structure and Evolution of Normal Galaxies”, Univ. of Cambridge Press, p. 67 Google Scholar
Villumsen, J., 1983 : Mon. Not Roy. Astron. Soc. 204 219 CrossRefGoogle Scholar
White, S.D.M., 1982 : in Martinet, L. and Mayor, M. (eds), “Morphology and Dynamics of Galaxies”, Geneva Obs. Switzerland, p. 390–406 Google Scholar