Program: GN-2006B-Q-65

How quick is chemical enrichment of the interstellar medium by young massive stars? If a large fraction of the new nucleosynthetic products from young stars are captured locally by the cold phase of the gas, enrichment takes place within a few millions years. If instead the new nucleosynthetic products are injected into a hot phase that can grow to several galactic scale heigths, enrichment time will be delayed by several 100 Myr, the timescale of cooling/condensation of hot gas. We will use GMOS-IFU to map the velocity fields and the chemical abundances in the nebular gas associated with the cores of nearby starburst regions. The goal of this spectral mapping is to explore the relations between the components of the velocity field (turbulence, super-shell expansion, and hypersonic blowout/breakout), the spatial abundance distribution and the ages/environments of these starbursts. We aim at establishing conditions under which immediate/local chemical enrichment takes place as opposed to the more diffuse and longer time scale mixing process. Our analysis will be supported by a detailed modelization of the evolution of starburst regions, using a stellar population evolutionary code and an ASPH hydrodynamic algorithm.