Steps of the determination of the range of integration for the moment-0 maps for the example source AG024.4616+0.1981 for H₂CO 3(0,3)-2(0,2) (top row) and CH₃CN 12_0,1 − 11_0,1 (bottom row). Top row from left: 1) mean spectrum over all the pixel with peak emission above 4 S/N, with its best fit and derived range of integration in magenta; 2) pixel with highest peak spectrum, with its best fit and derived range of integration in green; 3) spectrum of the pixel with the blue-wing terminating at the lowest velocity, marked by the blue vertical line; 4) spectrum of the pixel with the red-wing terminating at the highest velocity, marked by the red vertical line. Bottom row: same as top row, but for CH₃CN 12_0,1 − 11_0,1 for which a 2-Gaussian fit is performed to include both K=0 and K=1 line. No spectra are shown in the last two panel since no pixel was found with wings above the integration range defined by the first two panels.