2D periodograms of the 1083.3-nm He I triplet residual (with respect to the median) in the stellar rest frame, for the 2019B (left) and 2020B (right) spectra of AU Mic. In both periodograms, the dashed horizontal line traces P_rot and the orbital periods of the transiting and candidate planets, whereas the vertical dotted lines depict the velocities of the three components of the He I triplet. The color scale traces the logarithmic power in the periodograms. We caution that only the main peaks (colored yellow to red and extending over at least several velocity bins) are likely to be significant in these plots.