{
  "id": "1001.3298",
  "version": "v1",
  "published": "2010-01-19T13:38:43.000Z",
  "updated": "2010-01-19T13:38:43.000Z",
  "title": "Observations of the Large Magellanic Cloud with Fermi",
  "authors": [
    "The Fermi/LAT collaboration",
    "A. A. Abdo"
  ],
  "comment": "15 pages, 10 figures, A&A, in press",
  "categories": [
    "astro-ph.HE",
    "astro-ph.GA"
  ],
  "abstract": "Context: The Large Magellanic Cloud (LMC) is to date the only normal external galaxy that has been detected in high-energy gamma rays. High-energy gamma rays trace particle acceleration processes and gamma-ray observations allow the nature and sites of acceleration to be studied. Aims: We characterise the distribution and sources of cosmic rays in the LMC from analysis of gamma-ray observations. Methods: We analyse 11 months of continuous sky-survey observations obtained with the Large Area Telescope aboard the Fermi Gamma-Ray Space Telescope and compare it to tracers of the interstellar medium and models of the gamma-ray sources in the LMC. Results: The LMC is detected at 33 sigma significance. The integrated >100 MeV photon flux of the LMC amounts to (2.6 +/- 0.2) * 10^-7 ph/cm2/s which corresponds to an energy flux of (1.6 +/- 0.1) * 10^-10 erg/cm2/s, with additional systematic uncertainties of ~16%. The analysis reveals the massive star forming region 30 Doradus as a bright source of gamma-ray emission in the LMC in addition to fainter emission regions found in the northern part of the galaxy. The gamma-ray emission from the LMC shows very little correlation with gas density and is rather correlated to tracers of massive star forming regions. The close confinement of gamma-ray emission to star forming regions suggests a relatively short GeV cosmic-ray proton diffusion length. Conclusions: The close correlation between cosmic-ray density and massive star tracers supports the idea that cosmic rays are accelerated in massive star forming regions as a result of the large amounts of kinetic energy that are input by the stellar winds and supernova explosions of massive stars into the interstellar medium.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2010-01-19T13:38:43.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "large magellanic cloud",
      "massive star forming region",
      "gamma rays trace particle",
      "rays trace particle acceleration",
      "cosmic-ray proton diffusion length"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1051/0004-6361/200913474",
      "journal": "Astronomy and Astrophysics",
      "year": 2010,
      "month": "Mar",
      "volume": 512
    },
    "note": {
      "typesetting": "TeX",
      "pages": 15,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 843224,
      "adsabs": "2010A&A...512A...7A"
    }
  }
}