5σ mass sensitivity to companions in the PDS 66 system and the IRDIS H2 filter. The removal of the stellar halo was performed with ANDROMEDA, and AMES-DUSTY initial conditions are assumed for the perturber’s luminosity. The black dashed circumferences show the outer radius of the bright compact region at 25 au and the location of the outer ring at 85 au, respectively, as seen in scattered light by Avenhaus et al. (2018). The white thick circumference shows the proposed location of a perturber, at 55 au, creating the ring-like substructure, which coincidentally corresponds to a further depleted region in the scattered-light data. The black circle shows the location of the star and has a radius of 0.1′′. The 2D map has been deprojected based on the disk parameters of Table 1.