Enclosed gas mass fraction profiles. Points with error bars indicate f_gas obtained from the X-day data only; coloured envelopes show the f_gas obtained from the X-ray-SZ pressure profile combined with the X-ray density profile (see Sect. 4). The solid grey line shows the cosmic baryon fraction measured by Planck Collaboration XVI (2014); Y_B = 0.85 is the baryon depletion factor at R₅₀₀ from the simulations of Planelles et al. (2013). The dot-dashed line indicates R₂₀₀ ( ~ 1.5 R₅₀₀).