Folded velocity residuals (left) and detected clusters of peak velocities (right) in the disk reference frame. The green shaded annulus and wedge in the right plot mark the significant clusters in radius and azimuth, respectively. The position of the localized velocity perturbation inferred from these clusters is marked with a magenta point with error bars. The gray region (one beam size in radius) indicates the masked area, and the black dashed lines the FWHM of the dust ring.