Joint analysis of X-ray and Sunyaev Zel'dovich observations of galaxy   clusters using an analytic model of the intra-cluster medium
  We perform a joint analysis of X-ray and Sunyaev Zel'dovich (SZ) effect data using an analytic model that describes the gas properties of galaxy clusters. The joint analysis allows the measurement of the cluster gas mass fraction profile and Hubble constant independent of cosmological parameters. Weak cosmological priors are used to calculate the overdensity radius within which the gas mass fractions are reported. Such an analysis can provide direct constraints on the evolution of the cluster gas mass fraction with redshift. We validate the model and the joint analysis on high signal-to-noise data from the Chandra X-ray Observatory and the Sunyaev-Zel'dovich Array for two clusters, Abell 2631 and Abell 2204. 
Nicole Hasler, Esra Bulbul, Massimiliano Bonamente, John E. Carlstrom,   Thomas L. Culverhouse, Megan Gralla, Christopher Gr...
astro-ph.CO