Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gamma-ray variability of radio-loud narrow-line Seyfert 1 galaxies   The recent detection of gamma-ray emission from four radio-loud narrow-line
Seyfert 1 galaxies suggests that the engine driving the AGN activity of these
objects share some similarities with that of blazars, namely the presence of a
gamma-ray emitting, variable, jet of plasma closely aligned to the line of
sight. In this work we analyze the gamma-ray light curves of the four
radio-loud narrow-line Seyfert 1 galaxies for which high-energy gamma-ray
emission has been discovered by Fermi/LAT, in order to study their variability.
We find significant flux variability in all the sources. This allows us to
exclude a starburst origin of the gamma-ray photons and confirms the presence
of a relativistic jet. Furthermore we estimate the minimum e-folding
variability timescale (3 - 30 days) and infer an upper limit for the size of
the emitting region (0.2 - 2 pc, assuming a relativistic Doppler factor
delta=10 and a jet aperture of theta=0.1 rad).

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The categories of this paper are: q-bio
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The categories of this paper are: supr-con
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The categories of this paper are: eess
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The categories of this paper are: alg-geom
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The categories of this paper are: funct-an
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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: comp-gas
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The categories of this paper are: ao-sci
2
The categories of this paper are: math
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The categories of this paper are: dg-ga
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The categories of this paper are: patt-sol
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The categories of this paper are: atom-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex
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The categories of this paper are: solv-int