Mean age as a function of the radius. The dotted line is the mean age calculated with Le Phare and the continuous line is the median of the mock simulations (see section 3.4). The triangles represent the mode of the mean age of the mocks in a range of 20 arcsec. The gray dotted line is the R₂₅ while the black one is the R_UV. The shadow area is the area between the first and the third quartile of the mocks while the light area is the minimum and the maximum mean age found in the mocks.