Summary of the minimum distance, the UV-reprocessed and mechanical luminosities, and the intensities predicted for the PDR and shock scenario with a Gaussian distribution of shock velocities. Panel (a): Minimum distance as a function of the gas density. The dashed line represents a 0.5 dex limit (i.e., a factor of three difference between observed and modeled line intensities) to guide the eye. Panel (b): UV-reprocessed luminosity (orange) and mechanical luminosity (green) as functions of the gas density. The orange shaded area represents the SED estimation of the reprocessed UV-luminosity (see Appendix C). The green area represents < 1% of the estimated jet kinetic luminosity of 3C 326 N (see Sect. 4.3). Panel (c): Comparison between the observed line intensities and those obtained for the model at n_H = 10 cm⁻³, b = 0.1, G₀ = 10. The observations are presented as blue stars (see Table B.2) and the modeled intensities are shown as open black circles.