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Paper: The Role of the Dark Matter on the Formation of the Clusters of Galaxies
Volume: 176, Observational Cosmology: The Development of Galaxy Systems
Page: 210
Authors: Miranda, Oswaldo D.; de Araujo, José C. N.
Abstract: We present here preliminar results of studies concerning the dynamical evolution of primordial density perturbations with masses comparable to the groups and clusters of galaxies, that is, with masses ranging from 1012Modot to 1015 Modot. A spherical Lagrangian hydrodynamic code has been written to study the formation and evolution of these primordial perturbations, from the beginning of the recombination era (zrec ~1500) until the redshift when the collapse occurs. All the relevant processes are included in the calculations, as well as the expansion of the Universe. As initial condition we take different values for the Hubble constant, for the baryonic density parameter (Ω_B) and for the dark matter density parameter (ΩDM), as well as different density perturbation spectra, in order to see their influence on the behavior of the evolution of the objects that can collapse to form groups and clusters of galaxies. In particular, we find that the perturbations with dark matter collapse at higher redshift, when we compare the results with the purely baryonic models. As a general result we find that the distribution of the non-baryonic dark matter is more concentrated than the baryonic one. It is important to stress that we do not take into account the putative virialization of the non-baryonic dark matter, we just follow the time and spatial evolution of the density perturbation solving its hydrodynamical equations.
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