Bayes-X: a Bayesian inference tool for the analysis of X-ray observations of galaxy clusters


We present the first public release of our Bayesian inference tool for the analysis of X-ray observations of galaxy clusters, called Bayes-X. We illustrate the approach of Bayes-X by using it to analyse a set of four simulated clusters at z=0.2-0.9 in the X-ray band as they would be observed by a Chandra-like X-ray observatory. In both the simulations and the analysis pipeline we assume that the dark matter density follows a spherically-symmetric Navarro, Frenk and White (NFW) profile and that the gas pressure is described by a generalised NFW (GNFW) profile. We then perform four sets of analyses. These include prior-only analyses and analyses in which we adopt wide uniform prior probability distributions on f_g(r_{200}) and on the model parameters describing the shape and slopes of the GNFW pressure profile, namely (c_{500}, a, b, c). By numerically exploring the joint probability distribution of the cluster parameters given simulated Chandra-like data, we show that the model and analysis technique can robustly return the simulated cluster input quantities, constrain the cluster physical parameters and reveal the degeneracies among the model parameters and cluster physical parameters. The Bayes-X software which is implemented in Fortran 90 is available at this http URL

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Date added: Tue, 8 Oct 13