Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Second Chromatic Timing Event of Interstellar Origin toward PSR
  J1713+0747   The frequency dependence of radio pulse arrival times provides a probe of
structures in the intervening media. Demorest et al. 2013 was the first to show
a short-term (~100-200 days) reduction in the electron content along the line
of sight to PSR J1713+0747 in data from 2008 (approximately MJD 54750) based on
an apparent dip in the dispersion measure of the pulsar. We report on a similar
event in 2016 (approximately MJD 57510), with average residual pulse-arrival
times of approximately 3.0,-1.3, and -0.7 microseconds at 820, 1400, and 2300
MHz, respectively. Timing analyses indicate possible departures from the
standard nu^-2 dispersive-delay dependence. We discuss and rule out a wide
variety of potential interpretations. We find the likeliest scenario to be
lensing of the radio emission by some structure in the interstellar medium,
which causes multiple frequency-dependent pulse arrival-time delays.

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The categories of this paper are: alg-geom
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The categories of this paper are: solv-int
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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: stat
3
The categories of this paper are: physics
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The categories of this paper are: atom-ph
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The categories of this paper are: math
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The categories of this paper are: gr-qc
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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: acc-phys
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The categories of this paper are: quant-ph
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The categories of this paper are: adap-org
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The categories of this paper are: chem-ph
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The categories of this paper are: dg-ga