Comparison of gas turbulence between the two cluster SBs and two cluster MSs and field galaxies. The intrinsic velocity dispersion increases with redshift. The symbol convention and the two lines are the same as in the left panel of Fig. 5. The two lines show the relation between the gas velocity dispersion, the gas fraction, and the disk instability for different stellar masses (Wisnioski et al. 2015). Here we assume V_max = 130 km s⁻¹, Q = 1, and for a disk with constant rotational velocity. These tracks indicate that while σ₀ predictions from this relation depend on M_*, this dependency mostly vanishes at z >  2. The two cluster SBs have lower σ₀ than field SBs as well as most literature samples. Their uncertainties are derived from our simulation (see Sect. 3.6).