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Paper: Masses and Mass Distributions of Galaxies Calculated Using Numerical Action and Proper Motions from SIM
Volume: 194, Working on the Fringe: Optical and IR Interferometry from Ground and Space
Page: 74
Authors: Shaya, E.; Phelps, S.; Peebles, P. J. E.; Tully, R. B.
Abstract: The Least Action Variational method is an elegant non-chaotic technique for calculating the full trajectories of systems in a cosmological context. It has been used extensively on the Local Group in a series of papers by Peebles and for the Local Supercluster by the authors. We are now extending this analysis to find the trajectories back to t = 0 for about 100 individual galaxies within 5 Mpc plus about 1200 groups of galaxies beyond this domain extending to 3000 km/s. Our repertory of tools include code that hold distances constant and predict possible redshift, one that holds redshifts fixed and predict possible distances, and one that iterates on distances until a best overall model is found. We are also developing a new action principal to directly determine possible individual galaxy masses and mass distributions from a set of observed distances, redshifts, and proper motions. Multiplicity of solutions that ordinarily arise are greatly reduced by the additional observational information. The addition of proper motions and accurate distances that will be obtained from SIM will allow calculation of the mass distribions of galaxies and of groups, detection of additional mass other than that of known galaxies, if it exists, and a rigorous testing of the basic theories of cosmological structure formation.
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