Normalized pulse profiles in comparison. Dashed gray lines relate to calculations by Ferrigno et al. (2011, bottom right panel in their Fig. 9) and solid lines to the numerical ray tracing method presented here. Red and blue corresponds to the contribution of the two conical accretion columns with N₁ = N₂ = 100 positioned asymmetrically at (Θ_AC1 = 74°, Φ_AC1 = 178°) and (Θ_AC2 = 148°, Φ_AC2 = 293°), respectively, as shown by the inset. The lower panel shows the corresponding relative differences of the two ray tracing models. Both columns have a height of 2 km and an opening angle of 4°. The neutron star of mass 1.4 M_⊙ and radius 10 km is seen under an inclination of i = 60°.