Collapse indicators δV based on ideal C¹⁸O and ¹³CO observations. The upper and lower frames show, respectively, the northern and the southern clumps, for the same area as in Fig. 16. Frames a and d show δυ(proflle) that is computed from channels around the peak of the C¹⁸O spectrum. Frames b and e show the corresponding δυ (Gaussian) that is based on line parameters from Gaussian fits. For comparison, frames c and f show the skewness of the ¹³CO line profiles.