Virialization in N-body models of the expanding universe. II. All pairs
A previous investigation of the virialization of isolated pairs of galaxies, by testing the end product of the N-body simulations of Efstathiou and Eastwood, is extended to include all pairs, regardless of isolation. It is found that the nonisolated pairs do not satisfy the classical virial theorem as well as isolated pairs, but masses can be estimated to an accuracy of factors of 1.5 for the 0 = 0.1 model and 2 for the 0 = 0.1 model and 2 for the 0 = 1.0 model, over a range of separations 25 < H0 < 100 km s . Peebles's ''cosmic virial theorem'' is found to give mass estimates to somewhat better accuracy on the same scales. The calculation of the relative acceleration between pairs of mass points in the model from the three-point correlation function, using its empirical relation to the two-point correlation function is shown to be valid to an accuracy of a factor approx.1.5. Therefore, if the same results hold for the real universe, estimates of 0 based on such virial analyses should be accurate to better than a factor of 2. Comparison with observations then leads to the conclusion that 0 > 1.
- Research Organization:
- Astronomy Program, State University of New York at Stony Brook; and Institute of Astronomy, University of Cambridge
- OSTI ID:
- 6175404
- Journal Information:
- Astrophys. J.; (United States), Vol. 296:2
- Country of Publication:
- United States
- Language:
- English
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