Stacking results for peaked and non-peaked sources. Top left: average FWHM distributions of the [O III] detections in the peaked and non-peaked groups. Bottom left: stacked [O III] spectra of peaked and non-peaked sources, including non-detections. The shaded regions show the errors in the stacked spectra. The peaked sources show a significantly broad spectra on the blueshifted side, than the non-peaked sources. Bottom right: model fit to the peaked spectra, with the core and wing components marked. Top right: residuals after subtracting the model from the peaked spectra. The shaded region marks the standard deviation of the residuals.