{
  "id": "astro-ph/0008394",
  "version": "v1",
  "published": "2000-08-24T23:34:34.000Z",
  "updated": "2000-08-24T23:34:34.000Z",
  "title": "Quasar-galaxy associations revisited",
  "authors": [
    "N. Benitez",
    "J. L. Sanz",
    "E. Martinez-Gonzalez"
  ],
  "comment": "9 pages, 6 figures, MNRAS accepted",
  "journal": "Mon.Not.Roy.Astron.Soc. 320 (2001) 241",
  "doi": "10.1046/j.1365-8711.2001.03936.x",
  "categories": [
    "astro-ph"
  ],
  "abstract": "Gravitational lensing predicts an enhancement of the density of bright, distant QSOs around foreground galaxies. We measure this QSO-galaxy correlation w_qg for two complete samples of radio-loud quasars, the southern 1Jy and Half-Jansky samples. The existence of a positive correlation between z~1 quasars and z~0.15 galaxies is confirmed at a p=99.0% significance level (>99.9%) if previous measurements on the northern hemisphere are included). A comparison with the results obtained for incomplete quasar catalogs (e.g. the Veron-Cetty and Veron compilation) suggests the existence of an `identification bias', which spuriously increases the estimated amplitude of the quasar-galaxy correlation for incomplete samples. This effect may explain many of the surprisingly strong quasar-galaxy associations found in the literature. Nevertheless, the value of w_qg that we measure in our complete catalogs is still considerably higher than the predictions from weak lensing. We consider two effects which could help to explain this discrepancy: galactic dust extinction and strong lensing.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2000-08-24T23:34:34.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "correlation",
      "incomplete quasar catalogs",
      "surprisingly strong quasar-galaxy associations",
      "galactic dust extinction"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 9,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 547252
    }
  }
}