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Date and Time of the Query: 2019-04-25 T01:35:05 PDT
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For refcode 2006ApJ...640..691V:
Retrieve 13 NED objects in this reference.
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Copyright by American Astronomical Society. Reproduced by permission
2006ApJ...640..691V Chandra Sample of Nearby Relaxed Galaxy Clusters: Mass, Gas Fraction, and Mass-Temperature Relation Vikhlinin, A.; Kravtsov, A.; Forman, W.; Jones, C.; Markevitch, M.; Murray, S. S.; Van Speybroeck, L. Abstract. 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 {LAMBDA}CDM cosmology. However, in three cool clusters, we detect a central mass component in excess of the Navarro-Frenk-White profile, apparently associated with their cD galaxies. 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 an increase with both radius and cluster mass. The enclosed f_gas_ profiles within r_2500_~=0.4r_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 cosmic microwave background (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_. Key words: Cosmology: Observations, Cosmology: Dark Matter, Galaxies: Clusters: General, X-Rays: Galaxies: Clusters
Retrieve 13 NED objects in this reference.
Please click here for ADS abstract

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