Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Detection of VHE gamma-ray emission from the distant blazar 1ES 1101-232
  with H.E.S.S. and broadband characterisation   The blazar 1ES 1101-232 was observed with the High Energy Stereoscopic System
(H.E.S.S.) of Atmospheric Cherenkov Telescopes (ACT) in 2004 and 2005, for a
live time of 43 hours. VHE (E > 10^11 eV) gamma-rays were detected for the
first time from this object. VHE observations of blazars are used to
investigate the inner parts of the blazar jets, and also to study the
extragalactic background light (EBL) in the near-infrared band. Observations in
2005 were conducted in a multiwavelength campaign, together with the RXTE
satellite and optical observations. In 2004, simultaneous observations with
XMM-Newton were obtained. 1ES 1101-232 was detected with H.E.S.S. with an
excess of 649 photons, at a significance of 10 sigma. The measured VHE
gamma-ray flux amounts to dN/dE = (5.63 +- 0.89) x 10^-13 (E/TeV)^-(2.94 +-
0.20) cm^-2 s^-1 TeV^-1, above a spectral energy threshold of 225 GeV. No
significant variation of the VHE gamma-ray flux on any time scale was found.
1ES 1101-232 exhibits a very hard spectrum, and at a redshift of z=0.186, is
the blazar with the highest confirmed redshift detected in VHE gamma-rays so
far. The data allow the construction of truly simultaneous spectral energy
distributions of the source, from the optical to the VHE band. Using an EBL
model with \nu F_\nu = 14 nW m^-2 sr^-1 at 1.5 \mu m as presented in Aharonian
et al. (Nature, 2006, 440, 1018) suggests an intrinsic VHE power output peak of
the source at above 3 TeV.

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The categories of this paper are: chao-dyn
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The categories of this paper are: supr-con
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The categories of this paper are: nucl-ex
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The categories of this paper are: comp-gas
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The categories of this paper are: q-alg
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The categories of this paper are: acc-phys
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The categories of this paper are: quant-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-ph
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The categories of this paper are: stat
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The categories of this paper are: hep-th
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The categories of this paper are: mtrl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: math
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The categories of this paper are: ao-sci
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The categories of this paper are: atom-ph