ALMA observations of HD 100546 acquired in 2017 September. (a) Dust continuum emission map at 1.3 mm (I1.3 mm). (b) 12CO intensity map (zeroth moment, ICO). (c) Velocity map (first moment, v0) from 12CO(2–1) emission that shows perturbed non-Keplerian flows at the location of the continuum ring. (d) 12CO velocity dispersion map (second moment, σvel). Contours of I1.3 mm are plotted over moment maps with levels 0.15, 0.27, 0.40, 0.52, and 0.64 mJy beam−1. The lowest contour corresponds to 9σMEM. All panels display the same field of view.