Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Simultaneous Constraints on the Spectrum of the Extragalactic Background
  Light and the Intrinsic Tev Spectra of Mrk 421, Mrk 501, and H1426+428   Very high energy (~ TeV) $\gamma$-rays from blazars are attenuated by photons
from the extragalactic background light (EBL). Observations of blazars can
therefore provide an ideal opportunity for determining the EBL intensity if
their intrinsic spectrum is known. Conversely, knowledge of the EBL intensity
can be used to determine the intrinsic blazar spectrum. Unfortunately, neither
the EBL intensity nor the intrinsic blazar spectrum is known with high enough
precision to accurately derive one quantity from the other. In this paper we
use the most recent data on the EBL to construct twelve different realizations
representing all possible permutations between EBL limits and the detections in
the different wavelength regions. We use these realizations to explore the
effects of the EBL on the inferred spectra of blazars. In particular, we show
that the frequently cited "IR background-TeV gamma-ray crisis" does not exist,
and derive the intrinsic spectra and peak energies of the blazars Mrk 421, 501
and H1426+428 for EBL realizations that give rise to physically viable
intrinsic blazar spectra. We also show that the intrinsic spectrum of Mrk~421
during a period of intense flaring activity has a peak energy that seems to
shift to higher energies at higher flux states. Finally, we also explore the
effect of the uncertainties in the absolute calibration of the gamma-ray
energies on derived TeV opacities and the intrinsic blazar spectra.

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The categories of this paper are: nucl-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: math-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: econ
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The categories of this paper are: alg-geom
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The categories of this paper are: physics
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The categories of this paper are: hep-lat
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The categories of this paper are: funct-an
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The categories of this paper are: adap-org
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The categories of this paper are: nucl-th
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The categories of this paper are: q-alg
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-th
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The categories of this paper are: hep-ex
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The categories of this paper are: plasm-ph