ALMA observations of HD 100546 acquired in 2017 September. (a) Dust continuum emission map at 1.3 mm (I_{1.3 mm}). (b) ¹²CO intensity map (zeroth moment, I_CO). (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, σ_vel). Contours of I_{1.3 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 9σ_MEM. All panels display the same field of view.