Velocity field of the MWISP ¹²CO (1–0) emission (1st moment; color scale). The emission is integrated between −68 and −57 km s^-1. The yellow contour shows the intensity emission at the 5σ level (1σ~ 0.8 K km s^-1). The yellow dashed ellipse shows the cavity found in the ¹²CO image, while the red circle shows the position and size of the shell-like structure found in Tycho’s SNR. The four white dashed arrow lines show the routes of the position-velocity diagrams shown in Fig. 5.