Surface brightness and S/N in individual spaxels as a function of radius. Left: R-band surface brightness as a function of radius, from HST (black dots) and MUSE (red dots) data. The grey line indicates the two-disk model of Sil’chenko & Moiseev (2006) rescaled to R-band, highlighting the regions dominated by the disk surface brightness. The radial extent of the apertures shown in Fig. 1 are also indicated. Middle: S/N as a function of radius and per spectral resolution element, at 5100 Å. Right: same as middle, but now at 6400 Å. The colours in the middle and right panels indicate the density of individual spaxel measurements (redder colours means higher density).