Left panel: MZSFR for our sample of galaxies with a polynomial fit to these results overplotted (black dash-dotted line). In the bottom the residuals of the data fit, OH−OH_fit,M, are represented as a function of stellar mass. Central panel: These residuals of OH−OH_fit,M as a function of SFR with a minimum straight line fitting the points. The residual of this fit are represented at the bottom as a function of SFR: Right panel: residual of the latter fit, OH−OH_fit,M−Res_fit,SFR, as a function of the parameter D_n(4000). In the upper panels, the correlation coefficients for each fit are shown in the top right.