Best-model comparisons between CO observations and models for each observed shock: the blue- (upper panel) and the red- (lower panel) components. Observations are marked by the black squares, our individual best-shock models are in blue line and circles (ζ₁) or diamonds (ζ₂), the warm layer that we used to compensate the ambient emission affecting the (3–2) and (4–3) transitions in green line and triangles, and the sum of each of these components is represented by a red line and circles or diamonds.