{
  "id": "2001.05473",
  "version": "v1",
  "published": "2020-01-15T18:38:23.000Z",
  "updated": "2020-01-15T18:38:23.000Z",
  "title": "Metal enrichment in the circumgalactic medium and Lyα haloes around quasars at z $\\sim$3",
  "authors": [
    "Yucheng Guo",
    "Roberto Maiolino",
    "Linhua Jiang",
    "Kenta Matsuoka",
    "Tohru Nagao",
    "Oli Luiz Dors Junior",
    "Michele Ginolfi",
    "Nick Henden",
    "Jake Bennett",
    "Debora Sijacki",
    "Ewald Puchwein"
  ],
  "comment": "24 pages, 17 figures, submitted to the AAS journals",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "Deep observations have detected extended Ly{\\alpha} emission nebulae surrounding tens of QSOs at redshift 2 to 6. However, the metallicity of such extended haloes is still poorly understood. We perform a detailed analysis on a large sample of 80 quasars at z$\\sim$3 based on MUSE-VLT data. We find clear evidence of extended emission of the UV nebular lines C IV {\\lambda}1549 and He II {\\lambda}1640 for about 18$\\%$ of the sample, while C III] {\\lambda}1909 is only marginally detected in a few objects. By stacking the cubes we detect emission of C IV, He II and C III] out to a radius of about 45 kpc. C IV and He II show a radial decline much steeper than Ly{\\alpha}, while C III] shows a shallower profile similar to Ly{\\alpha} in the inner 45 kpc. We infer that the average metallicity of the circumgalactic gas within the central 30-50 kpc is $\\sim$0.5 solar, or even higher. However, we also find evidence of a component of the Ly{\\alpha} haloes, which has much weaker metal emission lines relative to Ly{\\alpha}. We suggest that the high metallicity of the circumgalactic medium within the central 30-50 kpc is associated with chemical pre-enrichment by past quasar-driven outflows and that there is a more extended component of the CGM that has much lower metallicity and likely associated with near-pristine gas accreted from the intergalactic medium. We show that our observational results are in good quantitative agreement with the expectations of the FABLE cosmological simulations.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2020-01-15T18:38:23.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "circumgalactic medium",
      "metal enrichment",
      "metallicity",
      "weaker metal emission lines relative",
      "past quasar-driven outflows"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 24,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}