{
  "id": "1711.03919",
  "version": "v1",
  "published": "2017-11-10T17:00:59.000Z",
  "updated": "2017-11-10T17:00:59.000Z",
  "title": "EW[OIII] as an orientation indicator for quasars: implications for the torus",
  "authors": [
    "Susanna Bisogni",
    "Alessandro Marconi",
    "Guido Risaliti",
    "Elisabeta Lusso"
  ],
  "comment": "9 pages, 3 figures, accepted for publication in Frontiers in Astronomy and Space Sciences, Research Topic \"Quasars at all cosmic epochs\"; proceedings of the conference \"Quasars at all cosmic epochs\", held in Padova, April 2-7, 2017",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We present an analysis of the average spectral properties of 12,000 SDSS quasars as a function of accretion disc inclination, as measured from the equivalent width of the [O III] 5007{\\AA} line. The use of this indicator on a large sample of quasars from the SDSS DR7 has proven the presence of orientation effects on the features of UV/optical spectra, confirming the presence of outflows in the NLR gas and that the geometry of the BLR is disc-like. Relying on the goodness of this indicator, we are now using it to investigate other bands/components of AGN. Specifically, the study of the UV/optical/IR SED of the same sample provides information on the obscuring \"torus\". The SED shows a decrease of the IR fraction moving from face-on to edge-on sources, in agreement with models where the torus is co-axial with the accretion disc. Moreover, the fact we are able to observe the broad emission lines also in sources in an edge-on position, suggests that the torus is rather clumpy than smooth as in the Unified Model. The behaviour of the SED as a function of EW[OIII] is in agreement with the predictions of the clumpy torus models as well.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-11-10T17:00:59.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "orientation indicator",
      "implications",
      "average spectral properties",
      "accretion disc inclination",
      "broad emission lines"
    ],
    "tags": [
      "conference paper"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 9,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}