Iu. Babyk, I. Vavilova, A. Del Popolo
We present results based on Chandra observations of a large sample of 129 hot galaxy clusters. We measure the concentration parameter c_200, the dark mass M_200 and the baryonic mass content in all the objects of our sample, providing the largest dataset of mass parameters for galaxy clusters in the redshift range z = 0.01 -- 1.4. We confirm that a tight correlation between c_200 and M_200, c \propto M^a_{vir}/(1+z)^b with a = -0.56 +/- 0.15 and b = 0.80 +/- 0.25 (68 per cent confidence limits), is present, in good agreement with the predictions from numerical simulations and previous observations. The inner slope $\alpha$ of the total mass density profile (\rho(r)\propto r^{-\alpha}) is derived from the slope of the integrated mass profile, using a generalized NFW model. The values of the inner slope \alpha, is \alpha = 0.94 +/- 0.13. Finally, we show that the inner slope of the density profile, \alpha correlates with the baryonic mass content, M_b: namely \alpha is decreasing with increasing baryonic mass content.
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http://arxiv.org/abs/1208.2424
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