English

The dynamical structure of dark matter halos with universal properties

Astrophysics 2011-02-11 v1

Abstract

NN-body simulations have unveiled several apparently universal properties of dark matter halos, including a cusped density profile, a power-law pseudo phase-space density ρ/σr3\rho/\sigma_r^3, and a linear βγ\beta-\gamma relation between the density slope and the velocity anisotropy. We present a family of self-consistent phase-space distribution functions F(E,L)F(E,L), based on the Dehnen-McLaughlin Jeans models, that incorporate these universal properties very accurately. These distribution functions, derived using a quadratic programming technique, are analytical, positive and smooth over the entire phase space and are able to generate four-parameter velocity anisotropy profiles β(r)\beta(r) with arbitrary asymptotic values β0\beta_0 and β\beta_\infty. We discuss the orbital structure of six radially anisotropic systems in detail and argue that, apart from its use for generating initial conditions for NN-body studies, our dynamical modeling provides a valuable complementary approach to understand the processes involved in the formation of dark matter halos.

Keywords

Cite

@article{arxiv.0809.0901,
  title  = {The dynamical structure of dark matter halos with universal properties},
  author = {Emmanuel Van Hese and Maarten Baes and Herwig Dejonghe},
  journal= {arXiv preprint arXiv:0809.0901},
  year   = {2011}
}

Comments

12 pages, 5 figures, accepted for publication in ApJ

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