Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A precise mass measurement of the intermediate-mass binary pulsar PSR
  J1802-2124   PSR J1802-2124 is a 12.6-ms pulsar in a 16.8-hour binary orbit with a
relatively massive white dwarf (WD) companion. These properties make it a
member of the intermediate-mass class of binary pulsar (IMBP) systems. We have
been timing this pulsar since its discovery in 2002. Concentrated observations
at the Green Bank Telescope, augmented with data from the Parkes and Nancay
observatories, have allowed us to determine the general relativistic Shapiro
delay. This has yielded pulsar and white dwarf mass measurements of 1.24(11)
and 0.78(4) solar masses (68% confidence), respectively. The low mass of the
pulsar, the high mass of the WD companion, the short orbital period, and the
pulsar spin period may be explained by the system having gone through a
common-envelope phase in its evolution. We argue that selection effects may
contribute to the relatively small number of known IMBPs.

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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: econ
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The categories of this paper are: solv-int
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The categories of this paper are: stat
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The categories of this paper are: gr-qc
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The categories of this paper are: patt-sol
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The categories of this paper are: cs
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The categories of this paper are: supr-con
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The categories of this paper are: quant-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: comp-gas
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The categories of this paper are: cond-mat
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The categories of this paper are: math-ph
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The categories of this paper are: hep-lat