Comparison of the mean mass-weighted stellar age (Gyr) and metallicity within R_B (cf. Sect. 2.2.2) with the values obtained within a radius of 3. ^′′3 for the LTG bulges in our sample ( and , respectively). Dashed diagonal lines indicate equality between both plotted quantities for spectral models based on the Z4 and Z5 SSP library (upper and lower panels, respectively). It can be seen that the scatter of points relative to the equality lines is relatively small (standard deviation of 0.56 Gyr and 0.33 dex for spectral fits with the Z4 SSP library and 0.63 Gyr and 0.60 dex for spectral fits with the Z5 SSP library) and does not show a significant dependence on age and metallicity.