Comparison of the resulting SFH using three levels of regularization. Top panel: resulting average SFH from a mock spectrum, perturbed 1000 times with S/N = 40, mimicking the SFH found in the thick disk (Fig. 5). It is the composition of two 10 and 14 Gyr [Mg/Fe]-enhanced SSPs, of different metallicity. Bottom panel: average SFH from MUSE data of the thick-disk spatial bins. In both panels, three different regularizations were used.