Top: E-mode maps stacked on the unoriented E-mode maxima computed above the null threshold ν = 0. Bottom: Q stacked around oriented polarization amplitude (P) maxima. In this case, no threshold is used and the orientation is chosen such that U = 0 and Q ≥ 0 on the central peak. The left panels are the stacked SMICA maps, and the right panels their corresponding NFEAs. See Fig. 46 for the meaning of the headless vectors (black dashed lines). The image units are  μK.