The H₂ excitation diagrams observed for each position indicated in Fig. 1, in black (pure rotational lines), and grey (rovibrational lines, when available). The data were corrected for extinction, using A_V = 2 from Giannini et al. (2004). The inferred rotational temperatures are indicated in black, and the rovibrational temperatures, in grey. The best-fitting model results are also shown in each case, in blue and/or red symbols. The shock parameters are given in each panel in the corresponding colour.