Spectra of the three GA transitions, obtained by integrating the emission inside the polygons defined for each shocked region. The blue line marks the zero intensity level of each spectrum, and the dotted red line shows the v_1sr of  L1157-mms, namely 2.6 km s⁻¹ with respect to the Sun. Note that the 8_1,8 − 7_0,7 transition is not detected in B0, and is slightly below the 3σ threshold in B1. Please also note that the emission of the GA transition at f = 85 782.24MHz spans over one channel only, whereas the other two GA lines display emission detected in 3 channels. This is likely due to the low intensity of the former and to the low spectral resolution (spectral resolution of 2 MHz, equivalent to ~ 7 km s⁻¹ at 85 782 MHz).