{
  "id": "astro-ph/0509799",
  "version": "v1",
  "published": "2005-09-27T10:27:08.000Z",
  "updated": "2005-09-27T10:27:08.000Z",
  "title": "A universal density slope - velocity anisotropy relation",
  "authors": [
    "Steen H. Hansen",
    "Ben Moore",
    "Joachim Stadel"
  ],
  "comment": "4 pages, 1 figure, to appear in the XXIst IAP Colloquium \"Mass Profiles and Shapes of Cosmological Structures\", Paris 4-9 July 2005, France, (Eds.) G. Mamon, F. Combes, C. Deffayet, B. Fort, EAS Publications Series",
  "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 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. 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, central density slope of \\alpha_0 = -0.8, and outer anisotropy of approximately \\beta_\\infinity = 0.5.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2005-09-27T10:27:08.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "velocity anisotropy relation",
      "universal density slope",
      "equilibrated dark matter structures",
      "phase-space density",
      "zero central velocity anisotropy"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1051/eas:2006042"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 4,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 693315,
      "adsabs": "2006EAS....20...33H"
    }
  }
}