Redshift distribution of the XXL-100-GC sample (filled histogram) compared with different model expectations. By default, the model predictions are based on the mass and temperature scaling relations of Papers III and IV, and assume a β-model with β = 2 / 3 and x₅₀₀ = 0.15. Left: the fiducial WMAP9 cosmology (red dashed line) compared with the Planck 2015 cosmological parameters obtained only from the CMB data (blue dot-dashed). Right: other models derived from Planck Collaboration XIII (2015). The Planck+External set of cosmological parameters includes additional BAO and H0 constraints (blue dashed). The green dot-dashed line is the same, but fixing σ₈ to the 1σ lower bound allowed by the Planck+External data set. The purple triple dot-dashed line uses the Planck-only parameters, but the normalisation of the M_500,WL − T_{300 kpc} scaling relation has been increased to its 1σ upper bound. The error bars (shown only for the WMAP9 and Planck+External cosmologies) include both the shot noise (thick part) and the cosmic variance.