{
  "id": "1203.3234",
  "version": "v1",
  "published": "2012-03-14T23:21:37.000Z",
  "updated": "2012-03-14T23:21:37.000Z",
  "title": "Fermi-LAT Discovery of GeV Gamma-ray Emission from the Vicinity of SNR W44",
  "authors": [
    "Yasunobu Uchiyama",
    "Stefan Funk",
    "Hideaki Katagiri",
    "Junichiro Katsuta",
    "Marianne Lemoine-Goumard",
    "Hiroyasu Tajima",
    "Takaaki Tanaka",
    "Diego Torres"
  ],
  "comment": "5 pages, accepted for publication in ApJL",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We report the detection of GeV gamma-ray emission from the molecular cloud complex that surrounds the supernova remnant (SNR) W44 using the Large Area Telescope (LAT) onboard Fermi. While the previously reported gamma-ray emission from SNR W44 is likely to arise from the dense radio-emitting filaments within the remnant, the gamma-ray emission that appears to come from the surrounding molecular cloud complex can be ascribed to the cosmic rays (CRs) that have escaped from W44. The non-detection of synchrotron radio emission associated with the molecular cloud complex suggests the decay of neutral pi mesons produced in hadronic collisions as the gamma-ray emission mechanism. The total kinetic energy channeled into the escaping CRs is estimated to be (0.3--3)x10^{50} erg, in broad agreement with the conjecture that SNRs are the main sources of Galactic CRs.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2012-03-14T23:21:37.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "gev gamma-ray emission",
      "snr w44",
      "fermi-lat discovery",
      "surrounding molecular cloud complex",
      "total kinetic energy"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/2041-8205/749/2/L35",
      "journal": "The Astrophysical Journal",
      "year": 2012,
      "month": "Apr",
      "volume": 749,
      "number": 2
    },
    "note": {
      "typesetting": "TeX",
      "pages": 5,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1093922,
      "adsabs": "2012ApJ...749L..35U"
    }
  }
}