Las relaciones de la formación estelar en galaxias luminosas en el infrarrojo

Résumé

Star formation takes place inside dense and cold clouds composed mainly of molecular gas and known as giant molecular clouds. Its study in galaxies is currently of great interest since we still do not understand the detailed physical mechanisms that drive the formation of stars. Progress in this area is key to understanding how galaxies form and evolve. The first studies of star formation found that the relation between the molecular gas traced by the CO molecule and the rate at which stars form remained constant across different populations of galaxies. More recent studies, however, cast doubt on the existence of a “universal” or “unimodal” relation valid at all spatial scales. In addition, the use of alternative tracers of molecular gas, such as HCN and HCO+, reveals stronger relations between the gas and the star formation rate than those found using CO. Also, observations carried out at smaller spatial scales show that differences in the gas properties depending on the internal structure of the galaxies (center, bar, disk) are correlated with variations in the star-formation efficiency. These recent studies suggest that the dynamical environment of the clouds in galaxies could determine the efficiency of star formation, a result that supports turbulent models...