Selected region in west ridge from ¹²CO FCRAO data for PDFs calculation is shown in the upper panel. The PDFs are computed using only lags in declination. The tick on left corner shows the physical scale. PDFs with different lags applied: δr = 2 (bold solid line), 5 (dotted line), 10 (thin solid line), and 15 (dashed line) are shown in the lower panel. The red line shows a Gaussian fit of δr = 15 PDF.