Velocity-integrated intensity channel maps of the MWISP ¹²CO (1–0) emission in the deep observations. In each panel, contour levels correspond to 3, 5, 7, 10, 14 σ, then increase in steps of 5 σ, where the 1 σ level is ~0.16 K km s⁻¹. The integrated velocity range is written in the bottom left corner of each panel (in km s⁻¹). The red ellipse shows the position and size (7′ × 5′) of the Crab Nebula, while the red dot at the center of the ellipse shows the FWHM beam (52″) in the MWISP ¹²CO observations at the position of the pulsar ($l={184}_{\cdot }^{\circ }56,b=-5_{\cdot }^{\circ }78$).