Modeling results and observations of the ¹²CO emission for the best-fitting physical model derived from the dust (see Fig. 3 and Table 4), with δ_gas = 1 (no drop in gas surface density inside the cavity). The observations are plotted in black, the models in purple. Left: ¹²CO spectrum integrated over the entire disk. Center: intensity cuts through the major (bottom) and minor (top) axis of the ¹²CO zero moment map. The noise level is indicated by the gray zone. The model images are convolved with the same beam as the ALMA observations. Right: amplitude of the integrated ¹²CO visibility for the deprojected baselines. The null line is indicated with a dashed line, and error bars indicate the noise.