Logarithms of the normalised m = 2 scattering coefficients averaged over twenty 256 × 256 column density maps from an MHD simulation (class 4, see Appendix B). The coefficients are given in lexicographical order (j₁, θ₁, j₂, θ₂). Top panel: fit using Eq. (14) plus additional terms discussed in Appendix C is shown (dashed orange line) on top of the data (solid blue line). The additional terms that have been taken into account in this fit are a lattice signature and a π∕2 harmonic forthe term. Bottom panel: residuals normalised to the standard deviation. Dotted lines correspond to ± 2σ.