Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Ratio of Luminous to Faint Red Sequence Galaxies in X-Ray and
  Optically Selected Low-Redshift Clusters   We study the ratio of luminous-to-faint red sequence galaxies in both
optically and X-ray selected galaxy clusters in the poorly studied redshift
range 0.05< z<0.19. The X-ray selected sample consists of 112 clusters based on
the ROSAT All-Sky Survey, while the optical sample consists of 266 clusters
from the Sloan Digital Sky Survey. Our results are consistent with the presence
of a trend in luminous-to-faint ratio with redshift, confirming that downsizing
is continuous from high to low redshift.
  After correcting for the variations with redshift using a partial Spearman
analysis, we find no significant relationship between luminous-to-faint ratio
and X-ray luminosity of the host cluster sample, in contrast to recent
suggestions. Finally, we investigate the stacked colour-magnitude relations of
these samples finding no significant differences between the slopes for
optically and X-ray selected clusters. The colour-magnitude slopes are
consistent with the values obtained in similar studies, but not with
predictions of theoretical models.

13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
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The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an