Component decomposition tests of the star formation histories in terms of mass fraction per age with evenly spaced age bins every 0.5 Gyr. The left and right columns show the star formation histories for thick and thin disks, respectively, for the five out of the eight galaxies containing two well-defined disk components. In each panel, the light blue solid line represents the component decomposition as in Fig. 4 with a adapted thin disk scale height of z_c1, whereas the dark blue dashed line represents a adapted thin disk scale height of z_c1/2. Uncertainties from Monte Carlo simulations are shown by the colored shaded areas. Large mass fractions at old ages should be handled with caution, as there might be a bias of PPXF fitting toward very old ages (see Sect. 5.2) and are shaded with a gray area.