{
  "id": "1611.02306",
  "version": "v1",
  "published": "2016-11-07T21:29:12.000Z",
  "updated": "2016-11-07T21:29:12.000Z",
  "title": "Coronal properties of the luminous radio-quiet quasar QSO B2202$-$209",
  "authors": [
    "E. S. Kammoun",
    "G. Risaliti",
    "D. Stern",
    "H. D. Jun",
    "M. Graham",
    "A. Celotti",
    "E. Behar",
    "M. Elvis",
    "F. A. Harrison",
    "G. Matt",
    "D. J. Walton"
  ],
  "comment": "8 pages, 4 figures, accepted for publication in MNRAS",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We present an analysis of the joint $XMM$-$Newton$ and $NuSTAR$ observations of the radio-quiet quasar QSO B2202$-$209. Using an optical observation from the Hale Telescope at the Palomar Observatory, we revise the redshift of the source from the previously reported $z=1.77$ to $z=0.532$, and we estimate the mass of the central black hole, $\\log (M_{\\rm BH}/M_{\\odot}) = 9.08 \\pm 0.18$. The X-ray spectrum of this source can be well described by a power-law of photon index $\\Gamma = 1.82 \\pm 0.05$ with $E_{\\rm cut} = 152_{-54}^{+103}\\,{\\rm keV}$, in the rest frame of the source. Assuming a Comptonisation model, we estimate the coronal temperature to be $kT_{\\rm e}=42\\pm 3 \\,{\\rm keV}$ and $kT_{\\rm e}= 56 \\pm 3\\,{\\rm keV}$ for a spherical and a slab geometry, respectively. The coronal properties are comparable to the ones derived for local AGN, despite a difference of around one order of magnitude in black hole mass and X-ray luminosity ($L_{2-10} = 1.93\\times 10^{45}\\,{\\rm erg\\,s^{-1}}$). The quasar is X-ray loud, with an unusually flat observed optical-to-X-ray spectral slope $\\alpha_{\\rm OX} = 1.00 \\pm 0.02$, and has an exceptionally strong optical [O III] line. Assuming that both the X-ray emission and the [O III] line are isotropic, these two extreme properties can be explained by a nearly edge-on disk, leading to a reduction in the observed UV continuum light.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2016-11-07T21:29:12.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "luminous radio-quiet quasar qso b2202",
      "coronal properties",
      "central black hole",
      "black hole mass",
      "optical-to-x-ray spectral slope"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 8,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}