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Spatially resolved emission-line spectroscopy is a powerful tool to determinethe physical conditions in the narrow-line region (NLR) of active galacticnuclei (AGNs). We recently used optical long-slit spectroscopy to study theNLRs of a sample of six Seyfert-2 galaxies. We have shown that such anapproach, in comparison to the commonly used [OIII] narrow-band imaging alone,allows us to probe the size of the NLR in terms of AGN photoionisation.Moreover, several physical parameters of the NLR can be directly accessed. Wehere apply the same methods to study the NLR of six Seyfert-1 galaxies andcompare our results to those of Seyfert-2 galaxies. We employ diagnosticallyvaluable emission-line ratios to determine the physical properties of the NLR,including the core values and radial dependencies of density, ionisationparameter, and reddening. Tracking the radial change of emission-line ratios indiagnostic diagrams allows us to measure the transition between AGN-like andHII-like line excitation, and thus we are able to measure the size of the NLR.In the diagnostic diagrams, we find a transition between line ratios falling inthe AGN regime and those typical for HII regions in two Seyfert-1 galaxies,thus determining the size of the NLR. The central electron temperature andionisation parameter are in general higher in type-1 Seyferts than in type 2s.In almost all cases, both electron density and ionisation parameter decreasewith radius. In general, the decrease is faster in Seyfert-1 galaxies than intype 2s. In several objects, the gaseous velocity distribution ischaracteristic for rotational motion in an (inclined) emission-line disk in thecentre. We give estimates of the black hole masses. We discuss our findings indetail for each object.

Size and properties of the narrow-line region in Seyfert-2 galaxies from spatially-resolved optical spectroscopy