The Role of Starburst in the Chemical Evolution of Galaxies

In a diagram of metallicity (~z) vs. luminosity (M${}_B$), the different types of nearby (Z $<0.05$) starburst galaxies seem to follow the same linear relationship as the normal spiral and irregular galaxies. However, for comparable luminosities the more massive starburst nucleus galaxies (SBNGs) show a slight metallic defficiency as compared to the giant spiral galaxies. Furthermore, the SBNGs do not seem to follow the same relationship between ~z and Hubble type (T) than the normal galaxies. The early-type SBNGs are metal poor as compared to normal galaxies. It may suggests that the chemical evolution of a majority of the nearby starbursts galaxies is not completely over and that the present burst represent an important phase of this process.