L_X–T scaling relation from Chandra mock spectra, for the region of the clusters encompassing R₅₀₀. Colour code: value of μ = σ_v( < R₅₀₀)/σ_thermal, calculated from gas velocities in the region encompassed by R₅₀₀. Observational data points (black diamonds) are from P09, with CC clusters marked with thicker black diamonds.