Cloudy simulation results for the Hβ shell. Top and middle rows correspond to models using the AGN normal and AGN soft continua as ionizing sources, respectively, while the lower row corresponds to the stellar ionizing source. Each panel shows the predicted line ratio log₁₀([O III] 5007/Hβ) as a function of gas density, n_H, and metallicity, Z, for inner shell radii of r_in = 0.1, 0.8, and 1.7 kpc (left to right). The maps are spanned by constant-density shell models with outer radius r_out = 1.8 kpc. Regions enclosed by the black contour are consistent with the observed constraint log₁₀([O III]/Hβ) < −1.15 from the extended emission in J0313-1806. The hatched areas indicate the radiation–pressure confinement (RPC) exclusion zone, where densities fall below the expected RPC floor and are therefore disfavored.