Ultraviolet spectral evolution of star clusters in the IUE library.

Abstract

The ultraviolet integrated spectra of star clusters and H II regions in the IUE library have been classified into groups based on their spectral appearance, as well as on age and metallicity information from other studies. We have coadded the spectra in these groups according to their S/N ratio, creating a library of template spectra for future applications in population syntheses in galaxies. We define spectral windows for equivalent width measurements and for continuum tracings. These measurements in the spectra of the templates are studied as a function of age and metallicity. We indicate the windows with a strong metallicity dependence, at different age stages.