Ratios between the 90% conservative upper limits on the Mach number (velocity/sound speed) that are scaled by the 1/3rd power of the spatial scale assuming Kolmogorov turbulence (see Sect. 5.2), and the Mach number, which is required to make a heating-cooling balance (see Eq. (2)). The point size provides the r₅₀₀, and the color is coded according to the central entropy, K₀, in units of keV cm².