Best-fit Gaussian profiles for the J = 13−12, K = 0−10 methyl cyanide lines at the central position in the Orion KL map. Identical line widths and central velocities are assumed for all K-ladder transitions within a given kinematic component (see Sect. 4.1 for details). Two kinematic components (one narrow, shown in blue, and one broad, shown in green) have been fitted while allowing their respective line widths and central velocities to vary. The combined fit from all Gaussian profiles is shown in red. The inset panel shows a zoom of the region around the K = 8−10 lines. The residual for the two-component fit is shown in black in the bottom panel; the residual for the best one-component fit is shown in grey for comparison. The residual for the fit using one kinematic component is noticeably worse than that with two.