Pseudo-NB images of the median stacked sample smoothed using a Gaussian kernel of standard deviation 0.3 arcsec. The top row shows, from left to right, the NB images of the [O II] (λ3727 + λ3729), Hβ, and [O III] (λ4960 + λ5008) line emission. The bottom row shows, from left to right, the NB images of the continuum emission near the [O II], Hβ, and [O III] lines. The red contour is plotted at three times the rms noise in the NB images.