SDSS sample of star-forming, inactive galaxies selected for this study, plotted in the M_∗−SFR parameter space. The grid of 50 bins used for the stacking is shown, with the bins colour-coded according to the number of spectra enclosed. The exact number of sources within each bin is indicated by the yellow text. The white dashed and dotted lines represent the MS relation of local star-forming galaxies with its ± 1σ scatter (=0.3 dex). The MS relation has been taken from Peng et al. (2010) and adapted to this dataset as explained in Sect. 2.2.