TeV gamma-ray observations of Compton Gamma-Ray Observatory pulsars: Evidence against inverse Compton controlled outer gaps

1993
8 pages
Published in:
  • Astrophys.J. 418 (1993) 836-843

Citations per year

199419961998200020024021
Abstract: (ADS)
We present the first results of TeV gamma-ray observations of the Compton Gamma-Ray Observatory gamma-ray pulsar PSR 1706-44, indicating a spectral cutoff between ˜20 GeV and 600 GeV. Improved upper limits are also presented for the Vela pulsar and PSR 1509-58. These and other TeV results confirm similar cutoffs for these gamma-ray pulsars as well as for Geminga. The polar cap model predicts such a spectral cutoff due to magnetic pair production, whereas the outer gap model for Vela-type pulsars predicts a similar cutoff resulting from the maximum synchrotron energy in the outer gap. The spectral flattening below a certain minimum energy, seen from all of these pulsars, is also consistent with the outer gap prediction. The predicted fluxes of TeV gamma-rays for Vela and Geminga are, however, much larger than the observed upper limits. These TeV observations place constraints on any pulsar model which employs the inverse-Compton scattering of soft photons by primary TeV electrons at distances relatively far from the stellar surface.
  • photon: cosmic radiation
  • cosmic radiation: particle source
  • pulsar
  • cosmic radiation: energy spectrum
  • energy spectrum: cosmic radiation
  • cosmic radiation: flux
  • flux: cosmic radiation
  • upper limit
  • experimental results
  • bibliography
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