Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Variable Optical Polarization and FERMI Observations of PMN
  J0948+0022   We report on observations of the {\gamma}-ray and optical photopolarimetric
behavior of the radio-loud, narrow line type-1 Seyfert galaxy PMN J0948+0022
over a twenty seven month period. As this object has recently been suggested to
represent a prototype of an emerging class of blazar-like objects, the observed
properties are compared to those of blazars. We extract doubling timescales of
roughly 4 hours for the optical and {\gamma}-ray bands. The rapid
microvariability in the optical/NIR, significant and variable optical
polarization, and strong yet rapidly-variable {\gamma}-ray emission we observe
for PMN J0948+0022 are all classical observational characteristics associated
with blazars. However, since these observations do not show a clear correlation
between the {\gamma}-ray and optical behavior, they do not offer conclusive
proof that the emissive behavior of PMN J0948+0022 is due to a relativistic jet
oriented close to our line of sight.

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The categories of this paper are: comp-gas
1
The categories of this paper are: cs
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
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The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
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The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
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The categories of this paper are: solv-int
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The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
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The categories of this paper are: plasm-ph
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The categories of this paper are: funct-an
9
The categories of this paper are: nlin