Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Chandra sample of nearby relaxed galaxy clusters: mass, gas fraction,
  and mass-temperature relation   We present gas and total mass profiles for 13 low-redshift, relaxed clusters
spanning a temperature range 0.7-9 keV, derived from all available Chandra data
of sufficient quality. In all clusters, gas temperature profiles are measured
to large radii (Vikhlinin et al.) so that direct hydrostatic mass estimates are
possible to nearly r_500 or beyond. The gas density was accurately traced to
larger radii; its profile is not described well by a beta-model, showing
continuous steepening with radius. The derived rho_tot profiles and their
scaling with mass generally follow the Navarro-Frenk-White model with
concentration expected for dark matter halos in LambdaCDM cosmology. In the
inner region (r<0.1r_500), the gas density and temperature profiles exhibit
significant scatter and trends with mass, but they become nearly self-similar
at larger radii. Correspondingly, we find that the slope of the
mass-temperature relation for these relaxed clusters is in good agreement with
the simple self-similar behavior, M_500 ~ T^alpha, where alpha=(1.5-1.6)+-0.1,
if the gas temperatures are measured excluding the central cool cores. The
normalization of this M-T relation is significantly, by =~ 30%, higher than
most previous X-ray determinations. We derive accurate gas mass fraction
profiles, which show increase both with radius and cluster mass. The enclosed
f_gas profiles within r_2500 =~ 0.4 r_500 have not yet reached any asymptotic
value and are still far (by a factor of 1.5-2) from the Universal baryon
fraction according to the CMB observations. The f_gas trends become weaker and
its values closer to Universal at larger radii, in particular, in spherical
shells r_2500<r<r_500.

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The categories of this paper are: stat
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The categories of this paper are: patt-sol
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The categories of this paper are: bayes-an
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The categories of this paper are: atom-ph
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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: solv-int
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The categories of this paper are: supr-con
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The categories of this paper are: hep-lat
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The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: adap-org
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The categories of this paper are: math
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The categories of this paper are: nucl-th
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The categories of this paper are: plasm-ph
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The categories of this paper are: chao-dyn