Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Seyfert Galaxies and the Hard X-ray Background: Artificial Chandra
  Observations of z = 0.3 Active Galaxies   Deep X-ray surveys have resolved much of the X-ray background radiation below
2 keV into discrete sources, but the background above 8 keV remains largely
unresolved. The obscured (type 2) Active Galactic Nuclei (AGNs) that are
expected to dominate the hard X-ray background have not yet been detected in
sufficient numbers to account for the observed background flux. However, deep
X-ray surveys have revealed large numbers of faint quiescent and starburst
galaxies at moderate redshifts. In hopes of recovering the missing AGN
population, it has been suggested that the defining optical spectral features
of low-luminosity Seyfert nuclei at large distances may be overwhelmed by their
host galaxies, causing them to appear optically quiescent in deep surveys. We
test this possibility by artificially redshifting a sample of 23 nearby,
well-studied active galaxies to z = 0.3, testing them for X-ray AGN signatures
and comparing them to the objects detected in deep X-ray surveys. We find that
these redshifted galaxies have properties consistent with the deep field
``normal'' and ``optically bright, X-ray faint'' (OBXF) galaxy populations,
supporting the hypothesis that the numbers of AGNs in deep X-ray surveys are
being underestimated, and suggesting that OBXFs should not be ruled out as
candidate AGN hosts that could contribute to the hard X-ray background source
population.

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The categories of this paper are: nlin
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The categories of this paper are: econ
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The categories of this paper are: q-fin
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The categories of this paper are: quant-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: supr-con
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The categories of this paper are: stat
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The categories of this paper are: q-alg
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The categories of this paper are: solv-int
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The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
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The categories of this paper are: atom-ph
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The categories of this paper are: q-bio
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The categories of this paper are: patt-sol
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The categories of this paper are: math