Computer Science approach to the stellar fabric of violent starforming regions in AGN

In order to analyse the large numbers of Seyfert galaxy spectra available at present, we are testing new techniques to derive their physical parameters fastly and accurately. We present an experiment on such a new technique to segregate old and young stellar popu- lations in galactic spectra using machine learning methods. We used an ensemble of classifiers, each classifier in the ensemble specializes in young or old populations and was trained with locally weighted regression and tested using ten-fold cross-validation. Since the relevant inform- ation concentrates in certain regions of the spectra we used the method of sequential floating backward selection offlinefor feature selection. Very interestingly, the application to Seyfert galaxies proved that this technique is very in- sensitive to the dilution by the Active Galactic Nucleus (AGN) continuum. Comparing with exhaustive search we concluded that both methods are similar in terms of accuracy but the machine learning method is faster by about two orders of magnitude.