Density profiles of sub-halos and dSph galaxies of the Milky Way

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The leading idea of all structure formation theories is that structures were born from small perturbations in the otherwise uniform distribution of matter in the early universe, which is supposed to be, to a great extent, dark. Cold dark matter (CDM) cosmology, even if very successful overall, predicts a large number of sub-structures in a galaxy-sized halo. The predicted number is much larger than the number of observed dwarf galaxies (the cosmological "sub-structure crisis")- Furthermore, the theoretical sub-halos have cuspy density profiles in contradiction to the cored profiles observed in the dwarf satellite galaxies in the MW (the cosmological "core problem"). The present project addresses the following issues: 1. We aim to study the "core problem" with a semi-analytical model that lakes into account the effects of random angular momentum and angular momentum acquired by tidal interaction with neighbouring proto-structures. 2. We also aim to study if and how dynamical friction can change density profile shapes. 3. We want to gain insights in the physics underlying the density profiles predicted by simulations, and therewith 4. to study the controversial universality of dark matter halo profiles.