Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: TeV gamma rays and cosmic rays from the nucleus of M87, a mis-aligned BL
  Lac object   The unresolved nuclear region of M87 emits strong non-thermal emission from
radio to X-rays. Assuming this emission to originate in the pc scale jet
aligned at $\theta \sim 30^\circ$ to the line of sight, we interpret this
emission in the context of the Synchrotron Proton Blazar (SPB) model. We find
the observed nuclear jet emission to be consistent with M87 being a mis-aligned
BL Lac Object and predict gamma-ray emission extending up to at least 100 GeV
at a level easily detectable by GLAST and MAGIC, and possibly by VERITAS
depending on whether it is high-frequency or low-frequency peaked. Predicted
neutrino emission is below the sensitivity of existing and planned neutrino
telescopes. Ultra-high energy neutrons produced in pion photoproduction
interactions decay into protons after escaping from the host galaxy. Because
energetic protons are deflected by the intergalactic magnetic field, the
protons from the decay of neutrons emitted in all directions, including along
the jet axis where the Doppler factor and hence emitted neutron energies are
higher, can contribute to the observed ultra-high energy cosmic rays. We
consider the propagation of these cosmic ray protons to Earth and conclude that
M87 could account for the observed flux if the extragalactic magnetic field
topology were favourable.

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The categories of this paper are: hep-ex
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The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
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The categories of this paper are: cond-mat
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The categories of this paper are: alg-geom
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The categories of this paper are: cs
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The categories of this paper are: hep-lat
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The categories of this paper are: q-bio
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The categories of this paper are: math-ph
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The categories of this paper are: econ
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The categories of this paper are: supr-con
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The categories of this paper are: comp-gas
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: ao-sci
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The categories of this paper are: math