{
  "id": "0803.0745",
  "version": "v2",
  "published": "2008-03-06T20:23:59.000Z",
  "updated": "2008-11-10T06:17:31.000Z",
  "title": "On the HI content, dust-to-gas ratio and nature of MgII absorbers",
  "authors": [
    "Brice Ménard",
    "Doron Chelouche"
  ],
  "comment": "9 pages, minor changes to match the version accepted for publication in MNRAS",
  "doi": "10.1111/j.1365-2966.2008.14225.x",
  "categories": [
    "astro-ph"
  ],
  "abstract": "We estimate the mean dust-to-gas ratio of MgII absorbers as a function of rest equivalent width W_0 and redshift over the range 0.5<z<1.4. Using the expanded SDSS/HST sample of low-redshift Lyman-alpha absorbers we first show the existence of a 8-sigma correlation between the mean hydrogen column density <N_HI> and W_0, an indicator of gas velocity dispersion. By combining these results with recent dust-reddening measurements we show that the mean dust-to-gas ratio of MgII absorbers does not appreciably depend on rest equivalent width. Assuming that, on average, dust-to-gas ratio is proportional to metallicity, we find its redshift evolution to be consistent with that of L^star galaxies from z=0.5 to 1.4 and we show that our constraints disfavor dwarf galaxies as the origin of such absorbers. We discuss other scenarii and favor galactic outflows from ~L^star galaxies as the origin of the majority of strong MgII absorbers. Finally, we show that, once evolutionary effects are taken into account, the Bohlin et al. relation between A_V and N_H is also satisfied by strong MgII systems down to lower column densities than those probed in our Galaxy.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2008-11-10T06:17:31.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "hi content",
      "mean dust-to-gas ratio",
      "rest equivalent width",
      "constraints disfavor dwarf galaxies",
      "gas velocity dispersion"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "Wiley-Blackwell",
      "journal": "Monthly Notices of the Royal Astronomical Society",
      "year": 2009,
      "month": "Mar",
      "volume": 393,
      "number": 3,
      "pages": 808
    },
    "note": {
      "typesetting": "TeX",
      "pages": 9,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 780792,
      "adsabs": "2009MNRAS.393..808M"
    }
  }
}