Thursday, July 12, 2012

1207.2468 (Alyson M. Brooks et al.)

Why Baryons Matter: The Kinematics of Dwarf Spheroidal Satellites    [PDF]

Alyson M. Brooks, Adi Zolotov
We use some of the highest resolution cosmological simulations ever produced of Milky Way-mass galaxies that include both baryons and dark matter to show that baryonic physics (energetic feedback from supernovae and subsequent tidal stripping) significantly reduces the dark matter mass in the central regions of luminous satellite galaxies. The reduced central masses of the simulated satellites reproduce the observed internal dynamics of Milky Way and M31 satellites as a function of luminosity. Including baryonic physics in Cold Dark Matter models naturally explains the observed low dark matter densities in the Milky Way's dwarf spheroidal population. Our simulations therefore resolve the tension between kinematics predicted in Cold Dark Mater theory and observations of satellites, without invoking alternative forms of dark matter.
View original: http://arxiv.org/abs/1207.2468

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