{
  "id": "astro-ph/0403352",
  "version": "v2",
  "published": "2004-03-15T20:30:10.000Z",
  "updated": "2004-03-16T20:29:22.000Z",
  "title": "Properties of Cold Dark Matter Halos at z>6",
  "authors": [
    "Renyue Cen",
    "Feng Dong",
    "Paul Bode",
    "Jeremiah P. Ostriker"
  ],
  "comment": "38 pages, submitted to ApJ, name revised (the first author name was wrong)",
  "categories": [
    "astro-ph"
  ],
  "abstract": "We compute the properties of dark matter halos with mass $10^{6.5}-10^9\\msun$ at redshift $z=6-11$ in the standard cold dark matter cosmological model, utilizing a very high resolution N-body simulation. We find that dark matter halos in these mass and redshift ranges are significantly biased over matter with a bias factor in the range 2-6. The dark matter halo mass function displays a slope of $2.05\\pm 0.15$ at the small mass end. We do not find a universal dark matter density profile. Instead, we find a significant dependence of the central density profile of dark matter halos on halo mass and epoch with $\\alpha_0=0.4-1.0$; the high-mass ($M\\ge 10^8\\msun$) low-redshift ($z\\sim 6$) halos occupy the high end of the range and low-mass ($M\\sim 10^{7}\\msun$) high-redshift ($z\\sim 11$) halos occupy the low end. Additionally, for fixed mass and epoch there is a significant dispersion in $\\alpha_0$ due to the stochastic assembly of halos. Our results fit a relationship of the form $\\alpha_0=0.75((1+z)/7.0)^{-1.25}(M/10^7\\msun)^{0.11(1+z)/7.0}$ with a dispersion about this fit of $\\pm 0.5$ and no systematic dependence of variance correlated with environment. The median spin parameter of dark matter halos is $0.03-0.04$ but with a large lognormal dispersion of $\\sim 0.4$. Various quantities are tabulated or fitted with empirical formulae.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2004-03-16T20:29:22.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "cold dark matter halos",
      "dark matter cosmological model",
      "dark matter density profile",
      "cold dark matter cosmological",
      "dark matter halo mass function"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 38,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 646312,
      "adsabs": "2004astro.ph..3352C"
    }
  }
}