Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The ESO Nearby Abell Cluster Survey. III. Distribution and Kinematics of
  Emission-Line Galaxies   We have studied the frequency of occurrence, the kinematics and the spatial
distribution of Emission-Line Galaxies (ELG) in clusters in the ESO Nearby
Abell Cluster Survey (ENACS). More than 90% of the ELG are spirals, but the ELG
represent only 30% of all spirals. The true ELG fraction in clusters is 0.10;
this is consistent with that in the field (0.21) as a result of differences in
morphological mix. The average ELG fraction decreases with increasing velocity
dispersion of the cluster. Only 1/5 of the clusters shows a significant
difference in the average velocities of the ELG and the other (non-ELG)
galaxies; in a similar fraction of the clusters significant differences in
velocity dispersion are seen. Yet, the velocity dispersion of the ELG is, on
average, 20% larger than that of the non-ELG. This larger velocity dispersion
is largely intrinsic, i.e. it is not likely to be the result of velocity
offsets of the ELG. The surface density of the ELG is significantly less peaked
towards the centre than that of the non-ELG. The ELG are distributed fairly
smoothly within the cluster with at most 25% in compact substructures. The
distribution and kinematics of the ELG yield virial mass estimates that, on
average, are 50% higher than those based on the non-ELG. This probably means
that the ELG are on more radial orbits than the non-ELG. All observed
properties of the ELG are consistent with most of them being on their first
approach of the high-density cluster core.

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The categories of this paper are: nucl-ex
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The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
20
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: chao-dyn
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The categories of this paper are: alg-geom
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The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con