Metal Enrichment in Galactic Winds

Abstract

Observations give evidences of the presence of metals in the intergalactic medium (IGM). The stars responsible for transforming hydrogen and helium into more complex atoms do not form outside the galaxies in the standard scenario of galaxy formation. Supernovae–driven winds and theirassociated feedback was proposed as a possiblesolution to explain such enrichment of the IGM. It turned out that a proper modelling of supernovaeexplosions within a turbulent interstellar medium (ISM) is a difficulttask. Recent advances have been obtained using a multiphase approachto solve for the thermal state of the ISM, plus some additionalrecipes to account for the kinetic effect of supernovae on thegalactic gas. We briefly describe here our implementation of supernovaefeedback within the RAMSES code, and apply it to the formation andevolution of isolated galaxies of various masses and angularmomenta. We have explored under what conditions a galactic wind candevelop, if one considers only a quiescent mode of star formation. We have also characterized the distribution and evolution of metallicity in the gas outflow spreading in the IGM.