Based on the stellar population synthesis code PEGASE (Fioc & Rocca-Volmerange 1997) we are currently creating a new library for classification in COMBO-17. The PEGASE spectra deliver us the M/L ratio for each SED type and each redshift for a given filter. The SED type and redshift estimation are results of the classification process. Together with the measured flux in one of our filters it enables us to establish an estimation of the stellar mass for each galaxy in our sample. For that purpose we use the 915 filter, which posesses the longest central wavelenght in our filterset. In the whole redshift regime up to redshift 1.2 that filter lies above the 400nm-break. Similar to investigation of the evolution of the luminosity function (Wolf et al. 2002) that mass estimation can be used to study the evolution of the stellar mass in galaxies.

Contact person: Andrea Borch, MPIA

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