Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Hubble Space Telescope Survey for Novae in the Globular Clusters of
  M87   The giant elliptical galaxy M87 has been imaged over 30 consecutive days in
2001, 60 consecutive days in 2005-2006, and every 5 days over a 265 day span in
2016-2017 with the Hubble Space Telescope, leading to the detection of 137
classical novae throughout M87. We have identified 2134 globular clusters (GC)
in M87 in these images, and carried out searches of the clusters for classical
novae erupting in or near them. One GC CN was detected in the 2001 data, while
zero novae were found during the 2005-2006 observations. Four candidate GC
novae were (barely) detected in visible light during the 2016-2017
observations, but none of the four were seen in near-ultraviolet light, leading
us to reject them. Combining these results with our detection of one M87 GC
nova out of a total of 137 detected CN, we conclude that such novae may be
overabundant relative to the field, but small number statistics dominate this
(and all other) searches. A definitive determination of GC CN overabundance (or
not) will require much larger samples which LSST should provide in the coming
decade.

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The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
22
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: q-alg
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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: ao-sci
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The categories of this paper are: q-fin
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The categories of this paper are: hep-ph
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The categories of this paper are: solv-int
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The categories of this paper are: funct-an