Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: What obscures low X-ray-scattering active galactic nuclei?   X-ray surveys have revealed a new class of active galactic nuclei (AGN) with
a very low observed fraction of scattered soft X-rays, f_scat < 0.5%. Based on
X-ray modeling these "X-ray new-type", or low observed X-ray scattering
(hereafter:"low-scattering") sources have been interpreted as deeply-buried AGN
with a high covering factor of gas. In this paper we address the questions
whether the host galaxies of low-scattering AGN may contribute to the observed
X-ray properties, and whether we can find any direct evidence for high covering
factors from the infrared (IR) emission. We find that X-ray low-scattering AGN
are preferentially hosted by highly-inclined galaxies or merger systems as
compared to other Seyfert galaxies, increasing the likelihood that the
line-of-sight toward the AGN intersects with high columns of host-galactic gas
and dust. Moreover, while a detailed analysis of the IR emission of
low-scattering AGN ESO 103-G35 remains inconclusive, we do not find any
indication of systematically higher dust covering factors in a sample of
low-scattering AGN based on their IR emission. For ESO 103-G35, we constrained
the temperature, mass and location of the IR emitting dust which is consistent
with expectations for the dusty torus. However, a deep silicate absorption
feature probably from much cooler dust suggests an additional screen absorber
on larger scales within the host galaxy. Taking these findings together, we
propose that the low f_scat observed in low-scattering AGN is not necessarily
the result of circumnuclear dust but could originate from interference of
host-galactic gas with a column density of the order of 10^22 cm^-2 with the
line-of-sight. We discuss implications of this hypothesis for X-ray models,
high-ionization emission lines, and observed star-formation activity in these
objects.

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The categories of this paper are: q-alg
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The categories of this paper are: q-bio
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The categories of this paper are: mtrl-th
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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-ex
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The categories of this paper are: solv-int
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The categories of this paper are: math-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: math
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The categories of this paper are: cs
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The categories of this paper are: adap-org
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-th
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The categories of this paper are: ao-sci
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The categories of this paper are: funct-an
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The categories of this paper are: quant-ph