J- and H-band combined image. The native image (12.25 mas px⁻¹) was binned by a factor of 4 and smoothed with a Gaussian filter of 2 binned pixels. The intensity scale is relative to the peak of the image. The color scale saturates (in yellow) at 0.5% of the peak. The mean signal in the southern spiral is detected at 3.9σ above background in the binned images, before smoothing. For comparison, the dust ring seen by ALMA is overplotted in red, to scale. A different rendering of the spirals in the J band, using a novel de-noising procedure (Price et al., in prep.), is presented in Fig. C.1.