Map of the color excess, E(B − V), computed based on observed Hα/Hβ line ratio (color scale). The western companion and the outflow show modest dust reddening, consistent with the lack of significant dust emission observed at millimeter wavelengths (shown in contours: log F_ν/[mJy] =  − 1.6, −1.5,  …  − 3; based on Decarli et al. 2019). Non-negligible extinction is reported for the eastern companion and for the bridge, while very high extinction is found on the northern edge of the quasar host galaxy.