1210.2721 (Yao-Yuan Mao et al.)

Halo-to-Halo Similarity and Scatter in the Velocity Distribution of Dark Matter    [PDF]

Yao-Yuan Mao, Louis E. Strigari, Risa H. Wechsler, Hao-Yi Wu, Oliver Hahn

We examine the velocity distribution function (VDF) in Dark Matter (DM) halos from Milky Way (MW) to cluster mass scales. We identify an empirical model for the VDF with a wider peak and a steeper tail than a Maxwell--Boltzmann distribution, and discuss physical explanations. We quantify sources of scatter in the VDF of cosmological halos and their implication for direct detection of DM. Given modern simulations and observations, we find that the most significant uncertainty in the VDF of the MW arises from the unknown radial position of the solar system relative to the DM halo scale radius.

View original: http://arxiv.org/abs/1210.2721