Le 23 mai 2014
De 10h30 à 12h00
Filippo FRATERNALI
University of Bologna – University of Groningen
Gas accretion is required to feed the star formation in disc galaxies throughout cosmic time. However, observational evidence for infalling gas clouds is rather scant. Cosmology tells us the most baryons are still outside galaxies in the intergalalactic medium and reach the highest densities in cosmological coronae surrounding every galaxy. These coronae represent huge reservoirs for gas accretion if they can be tapped with a mechanism that cools them and transfers their gas to the discs. In this talk, I present a new supernova-feedback model that uniquely uses gas ejected from galactic discs to induce the cooling and accretion of the circumgalactic medium (supernova-driven accretion). Observational support for this model is provided by studies of the kinematics of the gas around the Milky Way. I will discuss the possibility that this accretion mode is a fundamental channel of gas accretion onto star-forming galaxies for z<1.