(Left:) channel maps of the ¹²CO J = 2−1 line emission toward R Cas equivalent to those shown in Fig. 17, resulting from CLEANing with the SDI method. Contours are plotted at 3.5, 7, 10.5, 14, 19 and 24σ and from there each 8σ, where σ = 29 mJy beam^-1. Although the results obtained with different CLEANing methods allow emphasizing different structures, the resulted brightness distributions are very compatible. (Right:) the azimuthal average of the brightness distribution around the center is shown, at the systemic velocity (25 km s^-1), for both ¹²CO J = 1−0 and J = 2−1 emission. Peaks are found at the same radius for both transitions.