Model results aimed at reproducing the observed properties of the double notches in J0437−4715 (see Fig. 3). A rectangular void in emissivity, of a half width equal to 0.9° (thick line in a)), has been assumed to raise the central maximum of I at φ = 0. The layout of panels b)−d) is analogous to panels a)−c) in Fig. 7. List of parameters: ψ_B = −0.9φ, ψ_∥ = ψ_B−60°, , ρ_crv = 1.4 × 10⁵ cm, ν = 1 GHz.