Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: VERITAS detection of VHE emission from the optically bright quasar OJ
  287   We report on the VERITAS detection of very-high-energy (VHE, $E >
100~\mathrm{GeV}$) $\gamma$-ray emission from the optically bright quasar OJ
287 which is located at a redshift of z = 0.306. OJ 287 has been observed to
display regular optical outbursts with a period of approximately 12 years, with
the last major optical outburst having occurred in 2015. To explain this
periodicity, models involving a binary supermassive black hole system at the
core of OJ 287, or a helical jet, have been developed. Motivated by elevated
Swift-XRT count rates, VERITAS observed OJ 287 in February 2017, and detected
the object at >5 standard deviations above background. This detection prompted
further VERITAS, Swift-XRT and multiwavelength observations of the object. The
results of the VERITAS observational campaign are presented.

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The categories of this paper are: hep-th
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The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
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The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-lat
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The categories of this paper are: quant-ph
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The categories of this paper are: nlin
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The categories of this paper are: math
0
The categories of this paper are: hep-ph
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The categories of this paper are: q-bio