Images of the AB Aur system obtained with SPHERE in polarized light (a, b) and unpolarized light (c). A large field of view (10″) is shown in panel a, where the polarized intensity has been multiplied with the square of the stellocentric distance (Q_ϕ × r²) to visually enhance the outer part of the disk. A narrower field of view (2″) of the Q_ϕ map is displayed in panel b, in which the inner spirals are labelled S1 and S2. Comparable ADI-processed image is shown in panel c for total intensity in the H band filter. Features f1 and f2 are discussed in Sect. 4. North is up, east is left.