{
  "id": "0908.1171",
  "version": "v2",
  "published": "2009-08-08T14:29:42.000Z",
  "updated": "2009-08-26T03:29:10.000Z",
  "title": "Fermi LAT Observation of Diffuse Gamma-Rays Produced Through Interactions between Local Interstellar Matter and High Energy Cosmic Rays",
  "authors": [
    "A. A. Abdo"
  ],
  "comment": "accepted for publication in the Astrophysical Journal. Revised according to the author proof.(correction of typos and minor revisions)",
  "journal": "Astrophys.J.703:1249-1256,2009",
  "doi": "10.1088/0004-637X/703/2/1249",
  "categories": [
    "astro-ph.HE",
    "astro-ph.GA"
  ],
  "abstract": "Observations by the Large Area Telescope (LAT) on the \\textit{Fermi} mission of diffuse $\\gamma$-rays in a mid-latitude region in the third quadrant (Galactic longitude $l$ from $200\\arcdeg$ to $260\\arcdeg$ and latitude $| b |$ from $22\\arcdeg$ to $60\\arcdeg$) are reported. The region contains no known large molecular cloud and most of the atomic hydrogen is within 1 kpc of the solar system. The contributions of $\\gamma$-ray point sources and inverse Compton scattering are estimated and subtracted. The residual $\\gamma$-ray intensity exhibits a linear correlation with the atomic gas column density in energy from 100 MeV to 10 GeV. The measured integrated $\\gamma$-ray emissivity is $(1.63 \\pm 0.05) \\times 10^{-26} {\\rm photons s^{-1} sr^{-1} H\\mathchar`-atom^{-1}}$ and $(0.66 \\pm 0.02) \\times 10^{-26} {\\rm photons s^{-1} sr^{-1} H\\mathchar`-atom^{-1}}$ above 100 MeV and above 300 MeV, respectively, with additional systematic error of $\\sim 10%$. The differential emissivity in 100 MeV--10 GeV agrees with calculations based on cosmic ray spectra consistent with those directly measured, at the 10% level. The results obtained indicate that cosmic ray nuclei spectra within 1 kpc from the solar system in regions studied are close to the local interstellar spectra inferred from direct measurements at the Earth within $\\sim 10%$.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2009-08-26T03:29:10.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "high energy cosmic rays",
      "fermi lat observation",
      "local interstellar matter",
      "diffuse gamma-rays",
      "cosmic ray nuclei spectra"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "journal": "The Astrophysical Journal",
      "year": 2009,
      "month": "Oct",
      "volume": 703,
      "number": 2,
      "pages": 1249
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 828138,
      "adsabs": "2009ApJ...703.1249A"
    }
  }
}