Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Millisecond Time Variations of X-Ray Binaries   The Rossi X-Ray Timing Explorer (RXTE) has found that the neutron stars in
low-mass X-ray binaries exhibit oscillations in the range 300-1200 Hz.
Persistent emission may exhibit one or both of two features. In bursts a nearly
coherent pulsation is seen, which may be the rotation period of the neutron
star. For some the frequency equals the difference between the two higher
frequencies, suggesting a beat frequency model, but in others it is twice the
difference. Similar maximum frequencies suggests that it corresponds to the
Kepler orbit frequency at the minimum stable orbit or the neutron star surface,
either of which would determine the neutron star masses, radii and equation of
state. Theories of accretion onto black holes predict a quasi-periodic
oscillation (QPO) related to the inner accretion disk. The two microquasar
black hole candidates (BHCs) have exhibited candidates for this or related
frequencies.

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The categories of this paper are: acc-phys
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The categories of this paper are: stat
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-th
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The categories of this paper are: ao-sci
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The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: econ
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The categories of this paper are: plasm-ph
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The categories of this paper are: adap-org
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The categories of this paper are: supr-con
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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: math
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The categories of this paper are: q-bio
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The categories of this paper are: eess