Electron density [O III] diagnostic analysis for Oct. 2012 based on NOT spectra using the [O III] line ratios. Fluxes are corrected for E(B − V) = 0.85 (see discussion). Top: [O III] line profiles: 4363 Å (solid), disentangled from the blend with Hγ, 4959+5007 Å (dash). Bottom: derived n_e as a function of radial velocity. For | v_rad |  > 2000 km s^-1 the profiles are to weak for the ratio to be meaningful.