Baryons and Dark Matter Halo distribution in LCDM cosmology

PEDROSA, S.; TISSERA, P. B.; SCANNAPIECO, C.

Río de Janeiro, Brasil

Simposio; Stellar Populations:Planning for the next decade, IAU Symposium 262; 2009

IAU

We analyse the dark matter (DM) distribution in a ≈1012Mȯ halo extracted from a simulation consistent with the concordance cosmology, where the physics regulating the transformation of gas into stars was allowed to change producing galaxies with different morphologies. Although the DM profiles get more concentrated as baryons are collected at the centre of the haloes compared to a pure dynamical run, the total baryonic mass alone is not enough to fully predict the reaction of the DM profile. Our findings suggest that the response of the DM halo is driven by the history of assembly of baryons into a galaxy. The accretion of satellites could be associated with an expansion of the dark matter profiles, triggered by angular momentum transfer from the incoming satellites. However, we also found that these mechanism have different efficiencies which are set by the history of formation of the structure.