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| Paper: |
Mass-to-Light Ratio Measurements of Galaxies, Groups, and Clusters using the Numerical Action Method |
| Volume: |
209, Small Galaxy Groups, IAU Colloquium 174 |
| Page: |
445 |
| Authors: |
Shaya, Ed; Peebles, P. J. E.; Phelps, Steven; Tully, R. Brent |
| Abstract: |
The numerical action variational method (NAM) is an elegant, non-chaotic technique for calculating the trajectories of gravitating systems in a cosmological context. It has been used extensively for establishing orbits of Local Group galaxies in a series of papers (Peebles 1989, 1990, 1994, 1995) and for the Local Supercluster (Shaya, Peebles, & Tully 1995). Our repertoire of tools include code that holds present distances constant and predicts possible redshifts, one that holds present redshifts constant and predicts possible distances, and one that varies masses of each mass tracer and simultaneously satisfies both distance and redshift. Our results indicate a Ω0 = 0.2, a mass-to-light ratio of field galaxies in the range of 100 Modot / Lodot in blue light (t0 = 11 Gyr with no cosmological constant), but for the Virgo Cluster, the value is 6 or 7 times higher. The higher values of Ω0 determined from using the IRAS galaxy distributions may be a result of under weighting this important mass component of the universe plus a poor correlation between cluster and field galaxy distributions. |
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