Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Cluster and Large Scale Environments of Quasars at z<0.9   In this thesis, I present an investigation into the environments of quasars
with respect to galaxy clusters, and environment evolution with redshift and
luminosity. The orientation of the quasar with respect to the major axis of the
closest cluster was calculated, introducing new information to previous work.
The aim of this work was i.) to study the large scale environment over a large
redshift range, ii.) to study the evolution as well as any change in
environment with quasar luminosity and redshift, and iii.) to study the
orientation of a quasar with respect to a galaxy cluster.
  There is a deficit of quasars lying close to cluster centres for 0.4<z<0.8,
indicating a preference for less dense environments, in agreement with previous
work. These is no change with redshift (over 0<z<1.2) in the positions of the
quasars as a function of absolute quasar magnitude, nor preferred orientation
between the quasar and the cluster major axis for bright or faint quasars.
  Spectra of a selection of 680 star forming galaxies, red galaxies, and AGN
were taken, and used to study the environments of quasars with respect to
star-forming galaxies and galaxy clusters. The objects were classified (33
classed as AGN), and star formation rates calculated. Three AGN and 10 star
forming galaxies lie at the same redshift (z=0.29) as three galaxy clusters.
The three galaxy clusters have the same orientation angle and may be part of a
filament along with the star forming galaxies and AGN.
  A number of high redshift quasars showed evidence of ultra-strong UV FeII
emission in their spectra in the direction of three LQGs in the redshift range
1.1<z<1.6, including the Clowes-Campusano Large Quasar Group (CCLQG). Though
there has been no previous indication that the LQG environment is unique, the
high level of iron emission may indicate a difference in environment.

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The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
0
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: eess
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The categories of this paper are: supr-con
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: atom-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: dg-ga
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The categories of this paper are: patt-sol
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-lat
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The categories of this paper are: adap-org