Spectra of the SiO (8–7) emission (black line) toward different positions in the G35.20N star forming region: positions “out-NE” (top), “out-S” (middle) and “out-SW” (bottom) as indicated in Fig. 7. The emission has been obtained by integrating over areas of 1.34, 0.45 and 1.19 arcsec², which yield to conversion factors of 8.5, 25.3 and 9.6 K Jy^-1, respectively for the three panels. The red line corresponds to the C¹⁷O (3–2) line emission toward the three positions. In the middle panel, the blue dotted line corresponds to the SiO (8–7) line emission at the position of core A (over an area of 1.37 arcsec², which yields to a conversion factor of 8.9 K Jy^-1). The velocity component at ~16 km s^-1 corresponds to two blended CH₃CHO transitions. The two vertical dotted lines indicate the velocities of core A (31.8 km s^-1) and core B (29.6 km s^-1).