Results of the line of sight velocity map and extracted velocity perturbations from a VSI unstable disk ¹²CO(2–1) synthetic lines observations. The velocity centroid of the line was computed at each pixel from mock data cubes with a velocity resolution of 0.05 km s⁻¹. The input fields are shown in Fig. 3, which corresponds to a disk after ~ 0.3 Myr of evolution. From top to bottom: results for disk inclinations of 5°, 20° and 35°. First column: velocity centroid maps (v₀). The images are convolved by a circular Gaussian beam of 50 mas and have no noise. Second column: residual map of subtracting to v₀ the velocity centroid map obtained from a disk following an equilibrium solution (v_eq). Third column: residual of subtracting to v₀ the best fit disk model obtained using EDDY (v_mod). The images in this case are convolved by a 0.1 arcseconds circular Gaussian beam and have an RMS noise of ~ 1.5 mJy beam⁻¹. Fourth column: same as the third column, but for a 20 h Cycle 7 ALMA simulated observation using configurations C43-8 and C43-5, with an RMS noise of ~ 1.5 mJy beam⁻¹. The beam size is shown with a black circle at the bottom left of each panel. The black-dotted ellipses in panels of Cols. 3 and 4 are the inner and outer edge of the region considered to obtain the best fit model. The x- and y- axes indicate the RA and Dec angular offset from the central star’s position in arcseconds.