Resulting spectral stacks (solid black line) in bins of overdensity (high to low density from top to bottom panels) around the [OII] doublet. We show in green the best fit doublet model with each component shown as blue and red dashed lines. The shaded grey area represents the typical error on the fit of the spectra at each wavelength computed from the 16th and 84th percentiles of 10 000 realizations of perturbing the spectra by its error. In each panel we show the derived ratio between the two doublet components.