K-magnitude density distribution of RC stars outside the bulge minor axis centred at l = 10° and l = −10°. Only disk stars with | x | ≤ 2.5 kpc and | y | ≤ 3 kpc were selected. For each longitude, four latitudes centred at b = −4°, −6°, −8°, and −10°from top left to bottom right are shown. The size of the fields is Δl = Δb = 1° for b ≥ −6° and for b< − 6°. For each plot, all stars of the modelled galaxy are shown (black lines), as well as stars selected on their birth radii according to: r_ini< 2.5 kpc (blue lines), 2.5 kpc ≤r_ini< 4.5 kpc (red lines), and r_ini ≥ 4.5 kpc (green lines).