Bispectral coherence b(k, |m|) from LCT for selected values of |m|R_⊙ = 77.7, 155.5, 233.2 ± 12.3. The vector mR_⊙ is fixed for each plot and given by the orange arrow. The bispectral estimates were averaged over the direction of m, which is equivalent to assuming that there is no preferred horizontal direction and which results in a real bispectrum. The direction of m in the plot was chosen simply for convenience. The Fourier vectors for a triad k + l = m that corresponds to hexagons is given by the other two wave vectors (red: k, blue: l). The angles between the displayed Fourier vectors k, m, and l are not exactly 60 degrees because of the discretization. White color denotes locations where no estimate was obtained because one of the three vectors has zero length (as the mean was removed from each map, the bispectral coherence is not defined in this case). See Fig. 5 for a cut through the middle panel including error bars. See Figs. F.2–F.4 for further illustrations of these results and Fig. F.1 for the corresponding TD results.