{
  "id": "astro-ph/0510656",
  "version": "v1",
  "published": "2005-10-21T20:44:02.000Z",
  "updated": "2005-10-21T20:44:02.000Z",
  "title": "The velocity anisotropy - density slope relation",
  "authors": [
    "Steen H. Hansen",
    "Joachim Stadel"
  ],
  "comment": "15 pages, 7 figures",
  "journal": "JCAP 0605:014,2006",
  "doi": "10.1088/1475-7516/2006/05/014",
  "categories": [
    "astro-ph"
  ],
  "abstract": "One can solve the Jeans equation analytically for equilibrated dark matter structures, once given two pieces of input from numerical simulations. These inputs are 1) a connection between phase-space density and radius, and 2) a connection between velocity anisotropy and density slope, the \\alpha-\\beta relation. The first (phase-space density v.s. radius) has already been analysed through several different simulations, however the second (\\alpha-\\beta relation) has not been quantified yet. We perform a large set of numerical experiments in order to quantify the slope and zero-point of the \\alpha-\\beta relation. We find strong indication that the relation is indeed an attractor. When combined with the assumption of phase-space being a power-law in radius, this allows us to conclude that equilibrated dark matter structures indeed have zero central velocity anisotropy \\beta_0 = 0, central density slope of \\alpha_0 = -0.8, and outer anisotropy of \\beta_\\infty = 0.5.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2005-10-21T20:44:02.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "density slope relation",
      "equilibrated dark matter structures",
      "phase-space density",
      "zero central velocity anisotropy",
      "central density slope"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "IOP",
      "journal": "J. Cosmol. Astropart. Phys."
    },
    "note": {
      "typesetting": "TeX",
      "pages": 15,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 695906
    }
  }
}