EVOLUTIONARY MODELS FOR HIGH-METALLICITY GIANT EXTRAGALACTIC H-II REGIONS

We present theoretical models for giant H II regions of high metallici ty representative of those observed in the inner parts of spiral galax ies. The regions are ionized by young star clusters whose spectral ene rgy distributions are computed on the basis of evolutionary synthesis. The emergent ionizing continua are used as input for the photoionizat ion code CLOUDY to obtain the corresponding emission-line spectra that are then compared to existing observations. The possible implications on the IMF parameter determination for this kind of H II regions are discussed.