COMBINED POPULATION AND EVOLUTIONARY SYNTHESIS OF GALAXY SPECTRA

We present our numerical code to perform syntheses of galaxy spectra. Our modified linear simplex algorithm has the advantage that no initia l solution is required, the non-negativity for the individual contribu tions is guaranteed, additional spectral components can be added and i ndividual wavelength regions can be weighted. Synthesizing the observe d galaxy spectra with isochrone spectra we determine the age distribut ion of the stellar component. We demonstrate the accuracy of our metho d to reconstruct the age distribution of theoretical spectra. Finally, we present evolutionary syntheses of the optical spectra of an ellipt ical galaxy and of the spatially resolved Seyfert galaxy NGC 1365.