Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evidence of Increased UV FeII Emission in Quasars in Candidate Overdense
  Regions   We present evidence for a skewed distribution of UV FeII emission in quasars
within candidate overdense regions spanning spatial scales of ~ 50 Mpc at 1.11
< z < 1.67, compared to quasars in field environments at comparable redshifts.
The overdense regions have an excess of high equivalent width sources (W2400 >
42 \AA), and a dearth of low equivalent width sources. There are various
possible explanations for this effect, including dust, Ly\alpha fluorescence,
microturbulence, and iron abundance. We find that the most plausible of these
is enhanced iron abundance in the overdense regions, consistent with an
enhanced star formation rate in the overdense regions compared to the field.

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The categories of this paper are: adap-org
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The categories of this paper are: alg-geom
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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: cmp-lg
34
The categories of this paper are: chem-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: stat
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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: bayes-an