Spectra of the CENSORS sample, integrated over pixels where the [OIII] emission line is detected at SNR> 5. The left column shows spectra centered on the Hβ and [OIII] doublet emission lines and the right column is centered on the Hα + [NII] complex. All lines are well fitted by single Gaussians with the parameters listed in Table 2. Below each spectrum we show a typical night-sky spectrum to illustrate the position of bright night-sky lines (dashed lines). This spectrum is not to scale; the night-sky lines shown are typically at least factors of a few brighter than the emission lines from our targets. The bottom panel shows the fit residuals.