Top: distribution of the fitted line widths (left) and peak velocities (right) of the lines corresponding to molecules classified as “shock tracers”. Middle: distribution of the fitted line widths (left) and peak velocities (right) of every detected line in the line survey, except for the double-peaked and very asymmetric line profiles and the shock tracers shown above. Bottom: K-S test for the line width (left) and peak velocity (right) distributions shown above, corresponding to shock tracers only and to every other molecule that is not classified as a shock tracer. The parameter D is the maximum distance between the cumulative fraction of the shock tracers and the whole sample of lines and is related to the probability of a difference between the distributions. The part of the vertical dotted lines between the two distributions is equivalent to the D parameter.