Chemical Abundances and Evolution in Nearby Starbursts

We have constructed self-consistent models of starburst emission line spectra using both the PEGASE v2.0 and STARBURST99 codes to generate the spectral energy distribution (SED) of the young star clusters as input to the MAPPINGS III code (with dust included). We find that. giant extragalactic H II regions can be well-modelled, provided that they are mostly youngy, but that the models of older starbursts where there is a large contribution of UV photons from Wolf-Rayet stars fit the observations less well. This is the result of fundamental uncertainties in atmospheric, and. to a lesser extent, evolutionary models of these stars.