MATISSE and MIDI correlated fluxes. Top panel: each MATISSE correlated spectrum is color-coded by the individual baseline; in the legend, we specify the length and PA of each one. The apparent decrease in flux levels with increasing baseline length from top to bottom is indicative of a radial variation in the emitting region. Also shown here are the MIDI spectra (dashed black and gray lines) that follow a similar pattern. Bottom panel: the MATISSE correlated fluxes are plotted vs. spatial frequency and they are color-coded with respect to wavelength (as indicated in the color bar). The MIDI data are shown for reference (black and gray lines).