Galactic Winds in Starburst Irregular Galaxies

Abstract

In this paper we present some results of numerical simulations concerning the development of galactic winds in starburst galaxies. In particular, we focus on a galaxy similar to IZw18, the most metal-poor galaxy locally known. We compute the chemio-dynamical evolution of this galaxy, considering the energetic input and the chemical yields originating from Supernovae (SNe) of Type II and Ia and from intermediate-mass stars. We consider both single, instantaneous starburst and two starbursts separated by a quiescent period. In all considered cases a metal enriched winds develops and in particular the metals produced by Type Ia SNe are ejected more efficiently than the other metals. We suggest that two burst of star formation, the first being weaker and the last having an age of some tenth of Myr, can satisfactorily reproduce the abundances and abundance ratios found in literature for IZw18