Reconstructed maps of the effective density, multiplied by r², in the star meridian plane under the assumption of a wind velocity having the form obtained from the best fit of the model described in Sect. 4. The colour codes are such that the ratio between maximum and minimum values of ρr² are the same for CO(1−0) (left) and CO(2−1) (right). Units are Jy beam^-1 km s^-1 arcsec. The rectangles show the regions selected for displaying the ω distributions shown in Fig. 10 (for CO(1−0), abscissa between 0′′ and 3′′, ordinate between 5′′ and 9′′; for CO(2−1), abscissa between 2.0′′ and 5.4′′, ordinate between 1.8′′ and 5.2′′).