Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-25T15:58:57.168Z Has data issue: false hasContentIssue false

Formation of Double Galaxies by Tidal Capture

Published online by Cambridge University Press:  14 August 2015

S. M. Alladin
Affiliation:
Centre of Advanced Study in Astronomy, Osmania University, Hyderabad, India
A. Potdar
Affiliation:
Centre of Advanced Study in Astronomy, Osmania University, Hyderabad, India
K. S. Sastry
Affiliation:
Centre of Advanced Study in Astronomy, Osmania University, Hyderabad, India

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.

The conditions under which double galaxies may be formed by tidal capture are considered. Estimates for the increase in the internal energy of colliding galaxies due to tidal effects are used to determine the magnitudes Vcap and Vdis of the maximum relative velocities at infinite separation required for tidal capture and tidal disruption respectively. A double galaxy will be formed by tidal capture without tidal disruption of a component if Vcap > Vi and Vcap > Vdis where Vi is the initial relative speed of the two galaxies at infinite separation. If the two galaxies are of the same dimension, formation of double galaxies by tidal capture is possible in a close collision either if the two galaxies do not differ much in mass and density distribution or if the more massive galaxy is less centrally concentrated than the other. If we assume, as statistics suggest, that the mass of a galaxy is proportional to the square of its radius, it follows that the probability of the formation of double galaxies by tidal capture increases with the increase in mass of the galaxies and tidal disruption does not occur in a single collision for any distance of closest approach of the two galaxies.

Type
Part I/Spherical Systems
Copyright
Copyright © Reidel 1975 

References

Alladin, S. M.: 1965, Astrophys. J. 141, 768.CrossRefGoogle Scholar
Chandrasekhar, S.: 1939, An Introduction to the Study of Stellar Structure, University of Chicago Press, Chicago, Ch. 4.Google Scholar
Fish, R. A.: 1964, Astrophys. J. 139, 284.CrossRefGoogle Scholar
Potdar, A. and Ballabh, G. M.: 1974, Astrophys. Space Sci. 26, 353.CrossRefGoogle Scholar
Potdar, A.: 1974, ‘Tidal Force Effects in Clusters of Galaxies’, Osmania University ().Google Scholar
Rood, H. J.: 1965, ‘The Dynamics of the Coma Cluster of Galaxies’, University of Michigan ().Google Scholar
Sastry, K. S. and Alladin, S. M.: 1970, Astrophys. Space Sci. 7, 261.CrossRefGoogle Scholar
Sastry, K. S.: 1973, ‘Change in the Gravitational Energy of Galaxies due to Collisions and its Consequences’, Osmania University ().Google Scholar
Spitzer, L.: 1958, Astrophys. J. 127, 17.CrossRefGoogle Scholar
Toomre, A.: 1974, in Shakeshaft, J. R. (ed.), ‘The Formation and Dynamics of Galaxies’, IAU Symp. 58, 347.Google Scholar