CMD of the sources contained in each of the 4 annuli described in Sect. 4.4. The horizontal line in each frame marks the position of the TRGB at K₀ = 17.41 mag. No statistical adjustments have been made so foreground contamination that remained after the application of the J − H colour selection is also present in the CMDs and is expected to become increasing significant with increasing radial distance. The total number of sources and the total number of AGB sources is 2683 and 1325 respectively in the 0−1 kpc annuli, 1823 and 580 in the 1−2 kpc annuli, 1052 and 230 in the 2−3 kpc annuli and 1115 and 233 in the 3−4 kpc annuli.