{
  "id": "1307.3264",
  "version": "v3",
  "published": "2013-07-11T20:23:27.000Z",
  "updated": "2013-07-25T19:29:33.000Z",
  "title": "Gamma-ray observations of the microquasars Cygnus X-1, Cygnus X-3, GRS 1915+105, and GX 339-4 with the Fermi Large Area Telescope",
  "authors": [
    "Arash Bodaghee",
    "John A. Tomsick",
    "Katja Pottschmidt",
    "Jerome Rodriguez",
    "Joern Wilms",
    "Guy G. Pooley"
  ],
  "comment": "24 pages, 12 figures, 5 tables, accepted for publication in the Astrophysical Journal",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "Detecting gamma-rays from microquasars is a challenging but worthwhile endeavor for understanding particle acceleration, the jet mechanism, and for constraining leptonic/hadronic emission models. We present results from a likelihood analysis on timescales of 1 d and 10 d of ~4 years worth of gamma-ray observations (0.1-10 GeV) by Fermi-LAT of Cyg X-1, Cyg X-3, GRS 1915+105, and GX 339-4. Our analysis reproduced all but one of the previous gamma-ray outbursts of Cyg X-3 as reported with Fermi or AGILE, plus 5 new days on which Cyg X-3 is detected at a significance of ~5-sigma that are not reported in the literature. In addition, Cyg X-3 is significantly detected on 10-d timescales outside of known gamma-ray flaring epochs which suggests that persistent gamma-ray emission from Cyg X-3 has been detected for the first time. For Cyg X-1, we find three low significance excesses (~3-4-sigma) on daily timescales that are contemporaneous with gamma-ray flares reported (also at low significance) by AGILE. Two other microquasars, GRS 1915+105 and GX 339-4, are not detected and we derive 3-sigma upper limits of 2.3e-8 ph/cm2/s and 1.6e-8 ph/cm2/s, respectively, on the persistent flux in the 0.1-10 GeV range. These results enable us to define a list of the general conditions that are necessary for the detection of gamma-rays from microquasars.",
  "revisions": [
    {
      "version": "v3",
      "updated": "2013-07-25T19:29:33.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "fermi large area telescope",
      "gamma-ray observations",
      "microquasars cygnus",
      "persistent gamma-ray emission",
      "low significance excesses"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/0004-637X/775/2/98",
      "journal": "The Astrophysical Journal",
      "year": 2013,
      "month": "Oct",
      "volume": 775,
      "number": 2,
      "pages": 98
    },
    "note": {
      "typesetting": "TeX",
      "pages": 24,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1242383,
      "adsabs": "2013ApJ...775...98B"
    }
  }
}