Map of the CygX-N48 integrated intensity of CH₃CN from (Csengeri et al. 2011b) in greyscale, overlaid with the SiO systemic velocity emission from this paper in contours (for both molecules the velocity integration range was from −6.5 to −0.5 km s^-1). The red ellipses show the regions with narrow SiO emission adjacent to the clear velocity shear found in N₂H⁺, shown here as a blue line. Even though there are strong and compact SiO peaks coincident with high-velocity emission as seen in Fig. 5, the weaker and more extended SiO systemic velocity emission could be associated with the lower-velocity shocks from this velocity shear.