Statistical Analysis of the Galaxy Peculiar Velocity Field

NELSON D. PADILLA; MERCHÁN, MANUEL; DIEGO GARCIA LAMBAS

Workshop; 12th Potsdam Cosmology Workshop; 1997

We perform statistical analyses of the peculiar velocity field over samples of galaxies taken from Mark III catalog and N-body CDM COBE normalized numerical simulations with different values of the density parameters and cosmological constant. The statistical procedure analyzes the coherence of the flow as measured by the product of peculiar velocities of pairs of galaxies at different separations and their relative peculiar velocity distribution. In comparing models with observational data we have properly taken into account observational errors. We find that a 0.1 mag variation in the zero-point of the Tully-Fisher relation in addition to relative distance uncertainties ~= 15 % introduced in the Omega = 0.4 CDM model make statistical results comparable to observations. Models with large values of Omega ~= 0.8 may be ruled out with > 90 % statistical confidence.