²⁹SiO and CO emission in the sub-arcsec region. Upper left panel: ²⁹SiO(v = 0, J = 5 − 4) line (). The purple contours are at levels 30, 40, and 50% of the integrated emission peak. The green dash-dotted arrows describe the main directions of the total emission. The solid blue, red, and cyan contours are the blue-shifted, red-shifted, and systemic velocity emissions ([−15, −0.4], [0.3, 7.6], and [−0.4, 0.3] km s⁻¹). The dashed red contours describe the red-shifted absorption ([7.6, 15] km s⁻¹), which spatially matches the absorption of the v = 1 line. Upper right panel: CO(v = 0, J = 2 − 1) line (). The solid blue and red contours are the blue- and red-shifted emission ([−15, −3.4] and [1.2, 8.4] km s⁻¹). The cyan contours are the emission around the systemic velocity ([−3.4, 1.2] km s⁻¹; v_sys = −0.5 km s⁻¹). The dashed red contours are the red-shifted absorption. The solid and dashed purple contours are the emission and absorption of the CO(v = 1, J = 2 − 1) line ([−3.3, 6.9] and [6.9, 15] km s⁻¹). The thin yellow ellipse represents the star and the dash-dotted pink arrows define the main directions of the continuum emission. In both insets, the contours are at levels 70, 90, and 99% of the peak emission/absorption. The grey crosses position the continuum emission peak. Lower left and right panels: position-velocity diagrams of the ²⁹SiO(v = 0, J = 5 − 4) and CO(v = 0, J = 2 − 1) lines (left panel and right panel, respectively) along the corresponding main directions. The horizontal dotted lines are the limits between the previous velocity ranges. The yellow arrows (left panel) point out features in the diagrams typical of the emission of rotating gas. The blue dashed lines (right panel) connect the peak emissions along the northeast-southwest and southeast-northwest, revealing the dependence of the Doppler shift on the direction. The contours are at 3, 7, 15, 30, 50, 70, and 90% (²⁹SiO; 9.5σ ≃ 3%) and 30, 50, 70, 87, and 97% (CO; 5σ ≃ 3.6%) of the peak emissions.