Left panel: J-band Q_ϕ image reproduced from Benisty et al. (2017) in arbitrary intensity units with an overlay of the 12 and 25 σ contours of the ALMA data presented in Fig. 1. Central panel: inverted counterpart to the images shown in the left panel but with arbitrary contours of the SPHERE data overlayed on the ALMA data. Right panel: ALMA residuals after subtracting the best-fit disk, ring and central point source components summarized in Table 2 in visibility space, imaged using superuniform weighting. The same contours as shown for the SPHERE images in the central panel are again overlayed. The Gaussian component of the ALMA continuum emission appears to coincide well with the northern spiral arm seen in scattered light.