The classification and redshift estimation of galaxies in COMBO-17 relies on a library of galaxy templates based on UV-optical spectra of nearby galaxies measured by Kinney, Calzetti et al. (1996). However, there raises the issue that from measured spectra alone there is no further information about their astrophysical meaning. So the idea is to create another library, which is based on synthetic instead of measured spectra. For that purpose the stellar population synthesis code PEGASE (Fioc & Rocca-Volmerange 1997) is used in order to fit the Kinney et al. spectra. The new library is tested so far and when using it for classification instead of the Kinney et al. library it delivers mostly comparable redshifts. Once having the new library in hand it can be used in order to derive astrophysical conclusions from the SED classifications delivered by COMBO-17. For example, the M/L ratio derived from the PEGASE spectra can be used in order to establish an estimation of the stellar mass.

Contact person: Andrea Borch, MPIA

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