Velocity-channel maps of the SiO(2–1) emission. Black contour levels for the molecular line emission (in the  scale) are from 0.08 K (3σ) to 0.64 K in steps of 0.08 K. White contour levels are from 0.64 K in steps of 0.32 K. Dashed countours correspond to the −3σ level. Velocity channels range from −130 to 130 km s^-1 by steps of 5 km s^-1 (the velocity width per channel). The central velocities of the velocity-channel maps are shown in the upper-left corner of each panel. The wedge at the side shows the intensity scale of the SiO(2–1) emission. The beam size (30′′) is shown at the bottom-left corner. Sgr A^∗ is the origin for the offset coordinates (in arcseconds).