Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Modelling the multi-wavelength emission of flat spectrum radio quasar 3C
  279   We employ a length-dependent conical jet model for the jet structure and
emission properties of flat spectrum radio quasar 3C 279 in the steady state.
In the model, ultra-relativistic leptons are injected at the base of jet and
propagate along the jet structure, non-thermal photons are produced by both
synchrotron emission and inverse Comtpon scattering off synchrotron photons and
external soft photons at each segment of jet. We derive the total energy
spectra contribution through integrating every segment. We apply the model to
the quasi-simultaneous multi-wavelength observed data of two quiescent epoches.
Using the observed radio data of source, we determine the length of jet $L\sim
100$ pc, and magnetic field $B_{0}\sim 0.1-1$ G at the base of jet. Assuming a
steady geometry of the jet structure and suitable physical parameters, we
reproduce the multi-wavelength spectra during two quiescent observed epoches,
respectively. Our results show that the initial $\gamma$-ray emission site
takes place at $\sim 0.5$ pc from black hole.

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The categories of this paper are: math-ph
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The categories of this paper are: atom-ph
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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: hep-th
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The categories of this paper are: funct-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: bayes-an
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The categories of this paper are: gr-qc
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The categories of this paper are: cmp-lg
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The categories of this paper are: stat
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The categories of this paper are: adap-org
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The categories of this paper are: hep-ex
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The categories of this paper are: dg-ga
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The categories of this paper are: quant-ph
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The categories of this paper are: ao-sci