A dynamical model for the narrow line region of Seyfert galaxies

Detailed emission line ratios and profiles have been computed for the 'catapult' model of the NLR. According to this model the emission lines arise from interstellar clouds interacting with a wind from the central source. For clouds which are ejected by the ram pressure of the wind agreement is found with average Seyfert 2 line ratios for the main diagnostic lines, within the 2σ dispersions. This also gives the observed constancy of line profiles for different lines. The Seyfert 1 line ratios are obtained by adding a component of clouds which are not ejected. The predicted line ratios (relative to [O III]λ5007) for Seyfert 1s agree to better than 1σ with the observed averages. (author)