{
  "id": "0905.4400",
  "version": "v1",
  "published": "2009-05-27T12:32:51.000Z",
  "updated": "2009-05-27T12:32:51.000Z",
  "title": "Pulsed Gamma-rays from PSR J2021+3651 with the Fermi Large Area Telescope",
  "authors": [
    "A. A. Abdo"
  ],
  "comment": "Accepted by the Astrophysical Journal, 25 May 2009",
  "journal": "Astrophys.J.700:1059-1066,2009",
  "doi": "10.1088/0004-637X/700/2/1059",
  "categories": [
    "astro-ph.HE",
    "astro-ph.GA"
  ],
  "abstract": "We report the detection of pulsed gamma-rays from the young, spin-powered radio pulsar PSR J2021+3651 using data acquired with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). The light curve consists of two narrow peaks of similar amplitude separated by 0.468 +/- 0.002 in phase. The first peak lags the maximum of the 2 GHz radio pulse by 0.162 +/- 0.004 +/- 0.01 in phase. The integral gamma-ray photon flux above 100 MeV is (56 +/- 3 +/- 11) x 10^{-8} /cm2/s. The photon spectrum is well-described by an exponentially cut-off power law of the form dF/dE = kE^{-\\Gamma} e^(-E/E_c) where the energy E is expressed in GeV. The photon index is \\Gamma = 1.5 +/- 0.1 +/- 0.1 and the exponential cut-off is E_c = 2.4 +/- 0.3 +/- 0.5 GeV. The first uncertainty is statistical and the second is systematic. The integral photon flux of the bridge is approximately 10% of the pulsed emission, and the upper limit on off-pulse gamma-ray emission from a putative pulsar wind nebula is <10% of the pulsed emission at the 95% confidence level. Radio polarization measurements yield a rotation measure of RM = 524 +/- 4 rad/m^2 but a poorly constrained magnetic geometry. Re-analysis of Chandra data enhanced the significance of the weak X-ray pulsations, and the first peak is roughly phase-aligned with the first gamma-ray peak. We discuss the emission region and beaming geometry based on the shape and spectrum of the gamma-ray light curve combined with radio and X-ray measurements, and the implications for the pulsar distance. Gamma-ray emission from the polar cap region seems unlikely for this pulsar.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2009-05-27T12:32:51.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "fermi large area telescope",
      "pulsed gamma-rays",
      "gamma-ray emission",
      "fermi gamma-ray space telescope",
      "light curve"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "journal": "The Astrophysical Journal",
      "year": 2009,
      "month": "Aug",
      "volume": 700,
      "number": 2,
      "pages": 1059
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 821445,
      "adsabs": "2009ApJ...700.1059A"
    }
  }
}