Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Difference in Narrow Fe K\alpha Line Emission Between Seyfert 1 and
  Seyfert 2 Galaxies   We compile a sample of 89 Seyfert galaxies with both [OIV] 25.89 um line
luminosities observed by Spitzer IRS and X-ray spectra observed by XMM EPIC.
Using [OIV] emission as proxy of AGN intrinsic luminosity, we find that
although type 2 AGNs have higher line equivalent width, the narrow Fe Kalpha
line in Compton-Thin and Compton-Thick Seyfert 2 galaxies are 2.9 +0.8 -0.6 and
5.6 +1.9 -1.4 times weaker in terms of luminosity than Seyfert 1 galaxies
respectively. This indicates different correction factors need to be applied
for various types of AGNs before the narrow Fe Kalpha line luminosity could
serve as intrinsic AGN luminosity indicator. We also find Seyfert 1 galaxies in
our sample have on average marginally larger line width and higher line
centroid energy, suggesting contamination from highly ionized Fe line or
broader line emission from much smaller radius, but this effect is too weak to
explain the large difference in narrow Fe Kalpha line luminosity between type 1
and type 2 AGNs. This is the first observational evidence showing the narrow Fe
Kalpha line emission in AGNs is anisotropic. The observed difference is
consistent with theoretical calculations assuming a smoothly distributed
obscuring torus, and could provide independent constraints on the clumpiness of
the torus.

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The categories of this paper are: hep-ph
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The categories of this paper are: stat
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The categories of this paper are: nlin
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The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
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The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
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The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
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The categories of this paper are: solv-int
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The categories of this paper are: econ
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The categories of this paper are: alg-geom
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The categories of this paper are: dg-ga
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The categories of this paper are: cond-mat
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The categories of this paper are: cmp-lg
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The categories of this paper are: quant-ph