Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fermi Establishes Classical Novae as a Distinct Class of Gamma-Ray
  Sources   A classical nova results from runaway thermonuclear explosions on the surface
of a white dwarf that accretes matter from a low-mass main-sequence stellar
companion. In 2012 and 2013, three novae were detected in gamma rays and stood
in contrast to the first gamma-ray detected nova V407 Cygni 2010, which belongs
to a rare class of symbiotic binary systems. Despite likely differences in the
compositions and masses of their white dwarf progenitors, the three classical
novae are similarly characterized as soft spectrum transient gamma-ray sources
detected over 2-3 week durations. The gamma-ray detections point to unexpected
high-energy particle acceleration processes linked to the mass ejection from
thermonuclear explosions in an unanticipated class of Galactic gamma-ray
sources.

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The categories of this paper are: bayes-an
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The categories of this paper are: cond-mat
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The categories of this paper are: dg-ga
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The categories of this paper are: funct-an
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The categories of this paper are: stat
5
The categories of this paper are: gr-qc
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The categories of this paper are: hep-th
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-lat
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The categories of this paper are: solv-int
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-ex
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The categories of this paper are: nlin
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The categories of this paper are: patt-sol
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The categories of this paper are: adap-org
2
The categories of this paper are: math