{
  "id": "1806.11444",
  "version": "v1",
  "published": "2018-06-29T14:37:08.000Z",
  "updated": "2018-06-29T14:37:08.000Z",
  "title": "The two Ultraluminous X-ray sources in the galaxy NGC 925",
  "authors": [
    "F. Pintore",
    "L. Zampieri",
    "S. Mereghetti",
    "A. Wolter",
    "G. Rodríguez",
    "G. L. Israel",
    "P. Esposito",
    "S. Paiano",
    "G. Trinchieri",
    "P. Ochner"
  ],
  "comment": "Accepted on MNRAS with very minor comments, 7 pages, 5 figures, 1 table",
  "categories": [
    "astro-ph.HE",
    "astro-ph.GA"
  ],
  "abstract": "NGC 925 ULX-1 and ULX-2 are two ultraluminous X-ray sources in the galaxy NGC 925, at a distance of 8.5 Mpc. For the first time, we analyzed high quality, simultaneous XMM-Newton and NuSTAR data of both sources. Although at a first glance ULX-1 resembles an intermediate mass black hole candidate (IMBH) because of its high X-ray luminosity ($(2$$-$$4)\\times10^{40}$ erg s$^{-1}$) and its spectral/temporal features, a closer inspection shows that its properties are more similar to those of a typical super-Eddington accreting stellar black hole and we classify it as a `broadened disc' ultraluminous X-ray source. Based on the physical interpretation of this spectral state, we suggest that ULX-1 is seen at small inclination angles, possibly through the evacuated cone of a powerful wind originating in the accretion disc. The spectral classification of ULX-2 is less certain, but we disfavour an IMBH accreting at sub-Eddington rates as none of its spectral/temporal properties can be associated to either the soft or hard state of Galactic accreting black hole binaries.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-06-29T14:37:08.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "ultraluminous x-ray source",
      "galaxy ngc",
      "accreting black hole binaries",
      "accreting stellar black hole",
      "super-eddington accreting stellar black"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 7,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}