Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Environmental effects in the interaction and merging of galaxies in
  zCOSMOS survey   The zCOSMOS-bright 10k spectroscopic sample reveals a strong environmental
dependence of close kinematic galaxy pair fractions in the redshift range 0.2 <
z < 1. The fraction of close pairs is three times higher in the top density
quartile than in the lowest one. This environmental variation in pair fractions
will translate into merger fractions since merger timescales are shown, based
on Millennium simulation catalogs, to be largely independent of environment.
While galactic properties of close kinematic pairs (morphologies and star
formation rates) may seem to be non-representative of an underlying galaxy
population, they can be explained by taking into account well-known effects of
environment, and changes caused by interactions. The latter is responsible for
an increase of irregular galaxies in pairs by a factor of 50-75%, with a
disproportionate increase in the number of irregular-irregular pairs (4-8
times), due to disturbance of about 15% of the disk galaxies in pairs. Another
sign of interaction is an observed boost in specific star formation rate
(factor 2-4) for the closest pairs. While significant for paired galaxies, this
triggered star-formation due to interactions represents only about 5% of the
integrated star-formation activity in our volume-limited sample. Although
majority of close kinematic pairs are in dense environments, the effects of
interactions appear to be strongest in the lower density environments. This may
introduce strong biases into observational studies of mergers, especially those
based on morphological criteria. Relative excess of post-starburst galaxies
observed in paired galaxies (factor \sim2) as well as excess of AGNs (factor of
over 2), linked with environmental dependence of the pair fractions could
indicate that early phases of interactions and merging are plausible candidates
for environmental quenching, observed in the global galaxy populations.

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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: hep-lat
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The categories of this paper are: bayes-an
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The categories of this paper are: alg-geom
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The categories of this paper are: math-ph
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
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The categories of this paper are: eess
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The categories of this paper are: supr-con
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The categories of this paper are: atom-ph
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The categories of this paper are: stat
31
The categories of this paper are: ao-sci
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The categories of this paper are: solv-int
1
The categories of this paper are: cs
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The categories of this paper are: dg-ga