Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Comparison of Direct and Indirect Mass Estimates for Distant Clusters
  of Galaxies   We present weak lensing results for 12 distant clusters determined from
images obtained with the refurbished HST. We detect the signature of
gravitational lensing in 11 of the 12 clusters; the clusters span nearly an
order of magnitude in lensing strength. The sample thus provides an excellent
database for correlating direct mass estimates from lensing with indirect ones
which rely on baryonic tracers. We examine the correlation between the cluster
X-ray luminosities and the mean gravitational shear strengths and develop a
model which predicts the relationship expected from the properties of local
clusters. After allowing for various observational effects, we find that the
predicted correlation is a reasonable match to the available data, indicating
that there has been little evolution in the X-ray luminosity-central mass
relationship between z=0.4 and now. We discuss the implications of this result
in the context of the evolution of the X-ray luminosity function found by
earlier workers. The comparison between shear amplitudes and velocity
dispersions, estimated from a modest sample of members, reveals a discrepancy
in the sense that these velocity dispersions are typically over-estimated by
factors of ~50%. This supports earlier suggestions that high dispersions
measured for distant clusters may be seriously affected by both unidentified
substructure and outliers. Combining our lensing masses with
morphologically-based luminosity estimates, we determine mass/light ratios in
solar units of M/L_V=180+/-160 h for the entire population and 620+/-250 h for
the spheroidal galaxies where the evolutionary effects can be best treated. We
argue that this provides an upper bound to the local cluster M/L corresponding
to Omega~0.4.

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The categories of this paper are: nucl-ex
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The categories of this paper are: alg-geom
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The categories of this paper are: bayes-an
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The categories of this paper are: q-alg
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
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The categories of this paper are: plasm-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: cs
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The categories of this paper are: supr-con
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The categories of this paper are: hep-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: dg-ga
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The categories of this paper are: quant-ph
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The categories of this paper are: funct-an
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The categories of this paper are: comp-gas