Comparison of the best fitting CJ-type shock models and their predictions for the CO velocity-integrated flux distribution of the protostellar jet. The observational data are drawn with filled (empty) squares for a filling factor of 1 (of 0.25). Upper panel: a relative filling factor of 1 is assumed. Solutions with a pre-shock density n_H = 5 × 10⁴ (filled diamonds) and 10⁵ cm^-3 (filled circles), ν_s = 20−30 km s^-1, and age in the range ~220–450 yr, with the color code indicated in the figure are found to provide an equally good fit. Lower panel: a relative filling factor of 0.25 is assumed. Solutions with a pre-shock density n_H = 10⁵ cm^-3 (empty circles), ν_s = 25–30 km s^-1, and age in the range ~595–740 yr, with the color code indicated in the figure, provide a good fit to the data.