Median values of gas velocity dispersion σ_m in galaxies with R and B distributions. Panel a: σ_m as a function of the spectroscopic stellar mass M_sp for individual galaxies with R distribution (blue circles) and with B distribution (red squares). The solid line shows the median value of σ_m in galaxies with R distribution, and the dashed line shows the median value of σ_m for galaxies with B distribution. Panel b: median values of σ_m for galaxies in bins of 0.3 dex in M_sp for R-distribution galaxies (blue circles) and B-distribution galaxies (red squares). The lines come from panel a.