The patch like model of galaxies formation: the virial paradox, core-cusp and missing satellite problems

M. Demiański; A. Doroshkevich

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arXiv · 2009.04256

The patch like model of galaxies formation: the virial paradox, core-cusp and missing satellite problems

M. Demiański·A. Doroshkevich

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Abstract

The patch like model of the hierarchical galaxy formation in the $Λ$CDM cosmological model with small damping scale is considered. In this model galaxies and clusters of galaxies are identified with rare high density peaks, what suppresses the action of random factors in the vicinity of peaks and makes the process of halos formation more rapid and regular. High concentration of irregular subhalos surrounding the central peaks and their subsequent merging just after formation allows to consider this medium as a mixture of collisionless dispersed dark matter (DM) particles and collisional subhalos. Merging of these subhalos with the central dominating halo is accompanied by tidal destruction of the central cusp, what progressively shallows the density profile and promotes formation of super massive central black holes. In the framework of this model we can reproduce the observed correlation of mass and density of virialized galaxies and clusters of galaxies known as the virial paradox [4,5]. These correlations are closely linked with the composition of DM and the shape of the power spectrum what allows to restrict them using already available observations. These correlations put constraints on the HDM and WDM models and allow to test models of cosmological inflation. We confirm that the missing satellite problem is directly linked with the virial paradox and reheating of the Universe which increases temperature and entropy of the baryons, prevents formation of first stars and divides halos into two populations: the first one includes galaxies formed before reheating which are mainly concentrated in the vicinity of the massive ones while the second population -- numerous dark halos formed after reheating -- accumulates majority of DM but does not contain stars. Their spatial distribution is more homogeneous.

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M. Demiański, A. Doroshkevich. 2020-12-01. The patch like model of galaxies formation: the virial paradox, core-cusp and missing satellite problems. https://arxiv.org/abs/2009.04256

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