The massive Stellar Content in Starburst Galaxies and its Impact on Galaxy Evolution

Abstract

Starburst galaxies are powered by massive stars. These stars dominate the heating and enrichment with heavy elements of the interstellar medium, gas out of which new stars form. Thus, high-mass stars, and in consequence starburst galaxies, are an important (in some cases the dominant) energy source for the evolution of galaxies and the universe. In this contribution I review techniques to derive the massive stellar content in starburst galaxies and their evolutionary state. They are based on the analysis of their integrated light with evolutionary synthesis models. The massive stellar population is derived in a self-consistent way using the continuum and stellar wind resonance lines in the ultraviolet, the photospheric H Balmer and HeI lines and the nebular emission lines at optical wavelengths. Comparison with observations provides constraints on the most recent star formation history in starburst galaxies and their evolutionary state.