Left: minimum spanning trees showing projected distances between clumps. The two trees are constructed separately in the upper and in the lower observed region. Each tree node (denoted by the  ×  symbol) is at the position of the pixel with the highest brightness temperatures in a given clump (T_peak). Right: outlines of the ¹³CO clumps projected onto the lb-plane. Colors and line types correspond to those in Figs. 2–4 and B.1–B.5.