Spectra of the SiO (3–2) and SiO(5–4) transitions. Each color-coded solid curve plots the spectral data from each selected region listed in Table 2 from the data cube at their original spectral resolution. The spectral resolution of these lines are: 20.1 km s⁻¹ for SiO (3–2) and (5–4). The solid blue vertical lines are the SiO lines, the rest dashed blue vertical lines are bonus lines potentially covered by our spectral setup. Velocities refer to v_sys, LSRK = 1120 km s⁻¹. The blue shaded area indicates the velocity coverage we use to derive the velocity-integrated line intensities in our analysis at later stage. The grey solid horizontal line refers to the 1σ level for each transition.