{
  "id": "1002.1915",
  "version": "v1",
  "published": "2010-02-09T16:56:10.000Z",
  "updated": "2010-02-09T16:56:10.000Z",
  "title": "X/gamma-ray emission from hot accretion flows in AGNs",
  "authors": [
    "A. Niedzwiecki",
    "F. -G. Xie",
    "A. A. Zdziarski"
  ],
  "comment": "6 pages, proceedings of \"The Extreme sky: Sampling the Universe above 10 keV\"",
  "journal": "Proceedings of Science, PoS(extremesky2009)030",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We present preliminary results of our study of the impact of strong gravity effects on properties of the high energy radiation produced in accretion flows around supermassive black holes. We refine a model of the X-ray emission from a hot optically-thin flow by combining a fully general-relativistic (GR) hydrodynamical description of the flow with a fully GR description of Comptonization. We find that emission from a flow around a rapidly rotating black hole is dominated by radiation produced within the innermost few gravitational radii, the region where effects of the Kerr metric are strong. The X-ray spectrum from such a flow depends on the inclination angle of the line of sight to the symmetry axis, with higher angles characterised by a harder slope and a higher cut-off energy. Under the (reasonable) assumption that the equatorial plane of a rotating supermassive black hole is aligned with the surrounding torus, these predicted properties may provide a crucial extension of the unified model of AGNs, allowing to reconcile the model with systematic trends reported in a number of studies of the X-ray spectral properties of AGNs (indicating that type 2 objects are harder than type 1 and that the relative amount of the reflected radiation is larger in the latter). On the other hand, the model with a rapidly rotating black hole predicts larger apparent luminosities for objects observed at higher viewing angles, while an opposite property (i.e. type 1 objects being more luminous than type 2) was revealed in the Integral data.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2010-02-09T16:56:10.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "hot accretion flows",
      "x/gamma-ray emission",
      "predicts larger apparent luminosities",
      "black hole predicts larger",
      "hole predicts larger apparent"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 6,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 845388,
      "adsabs": "2009essu.confE..30N"
    }
  }
}