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The Spectrum of 1ES0229 + 200 and the Cosmic Infrared BackgroundAims. We reexamine the implications of the recent HESS observations of the blazar 1ES0229+200 for constraining the extragalactic mid-infrared background radiation. Methods. We examine the effect of gamma-ray absorption by the extragalactic infrared radiation on predicted intrinsic spectra for this blazar and compare our results with the observational data. Results. We find agreement with our previous results on the shape of the infrared spectral energy distribution, contrary to the recent assertion of the HESS group. Our analysis indicates that 1ES0229+200 has a very hard intrinsic spectrum with a spectral index between 1.1 +/- 0.3 and 1.5 0.3 in the energy range between 0.5 TeV and 15 TeV. Conclusions. Under the assumptions that (1) the models of Stecker et al. as derived from numerous detailed infrared observations are reasonable, and (2) spectral indexes in the range 1 < Gamma < 1.5 are obtainable from relativistic shock acceleration under the astrophysical conditions extant in blazar flares, the fits to the observations of 1ES0229+200 using our previous infrared spectral energy distributions are consistent with both the infrared and -ray observations. Our analysis presents evidence indicating that the energy spectrum of relativistic particles in 1ES0229+200 is produced by relativistic shock acceleration, producing an intrinsic gamma-ray spectrum with index 1 < Gamma < 1.5 and with no evidence of a peak in the spectral energy distribution up to energies approximately 15 TeV.
Document ID
20080038689
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Stecker, F. W.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Scully, S. T.
(James Madison Univ. Harrisonburg, VA, United States)
Date Acquired
August 24, 2013
Publication Date
January 1, 2008
Publication Information
Publication: Astronomy and Astrophysics
Publisher: EDP Sciences
Volume: 478
Subject Category
Astrophysics
Funding Number(s)
CONTRACT_GRANT: J-805
Distribution Limits
Public
Copyright
Other

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