Velocity field maps of SiO (top) and N₂H⁺ (bottom). The black contours are the 3.6 mm continuum emission. The N₂H⁺ velocity field map is generated by fitting hyperfine structure lines of N₂H⁺ per pixel using XCLASS while the SiO velocity map is the intensity-weighted velocity of the spectral line (i.e., moment 1 map). The black symbols are YSOs, and they are the same as presented in Fig. 2. The velocity ranges in the color bars for both maps are fixed as the same.