Galaxies and Clusters of Galaxies in Observations and Numerical Models.

An analysis of the properties of 1157 galaxies, groups and clusters of galaxies confirms the dependence of the virial velocity on the halo mass with a single exponent and different values of km/s for galaxies with and km/s for galaxy clusters with . A single exponent confirms the high degree of universality of the dark matter halo formation processes, and the difference in values of corresponds to the well-known difference in the average densities of galaxies and galaxy clusters and introduces a new scale into the perturbation power spectrum. Modern numerical models using the power spectrum obtained from the WMAP and Planck observations reproduce well the observed properties of galaxy clusters, but cannot reproduce the observed parameters of galaxies. It is also shown that the cusp in the dark matter density profile leads to a finite density of gas and stars at the center of the halos (Burkert profile). [ABSTRACT FROM AUTHOR]