What regulates star-formation in galaxies ?

Séminaire IPAG de Nicolas Bouche (University of California), jeudi 17 mars 2011 à 11h00, IPAG seminar room

Globally, the efficiency to form galaxies is low, only 5% of the baryons made it into stars. Moreover, this efficiency is a strong function of mass, and peaks at around 20% for halos similar to the Milky Way. What causes this efficiency to decline in low mass galaxies ? Feedback is traditionally attributed to this for various reasons. We will address this issue from the point of view of the scaling relations. Indeed, galaxies form stars along a tight sequence, that evolves with redshift. We will discuss the roles of feedback and accretion on the global properties of galaxies.