Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optical study of PKS B1322-110, the intra-hour variable radio source   Observations with the Australia Telescope Compact Array revealed intra-hour
variations in the radio source PKS B1322-110 (Bignall et al. 2019). As part of
an optical follow-up, we obtained Gemini Halpha and Halpha continuum (HalphaC)
images of the PKS B1322-110 field. A robust 19-sigma detection of PKS B1322-110
in the Halpha-HalphaC image prompted us to obtain the first optical spectrum of
PKS B1322-110. With the Gemini spectrum we determine that PKS B1322-110 is a
flat-spectrum radio quasar at a redshift of z=3.007 +/- 0.002. The apparent
flux detected in the Halpha filter is likely to originate from HeII emission
redshifted precisely on the Galactic Halpha narrow-band filter. We set upper
limits on the emission measure of the Galactic plasma, for various possible
cloud geometries.

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The categories of this paper are: nlin
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The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
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: stat
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The categories of this paper are: hep-ph
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The categories of this paper are: eess
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The categories of this paper are: cs
34
The categories of this paper are: chem-ph
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The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
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The categories of this paper are: econ
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The categories of this paper are: acc-phys
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The categories of this paper are: solv-int