The Downsizing of Galaxies versus the Upsizing of Dark-Halos in a Lambda-CDM

DE ROSSI, MARÍA EMILIA; ÁVILA-REESE, VLADIMIR; TISSERA, PATRICIA BEATRIZ; PEDROSA, SUSANA ELIZABETH

Santiago de Chile

Workshop; Multiwavelength Views of the ISM in High-Redshift Galaxies; 2011

European Southern Observatory

The formation histories of galaxies are studied simultaneously with the hierarchical aggregation of their parent dark-matter halos by using hydrodynamical numerical simulations within a Lambda-CDM cosmology.  Our preliminary results show that dark-halos assemble hierarchically in the sense that low-mass systems acquire most of their mass earlier than more massive ones, consistently with previous works.  On the other hand,  the astrophysical processes included in these simulations (star formation, Supernova feedback, etc) are capable of reproducing a dowsizing scenario for galaxies contrary to the upsizing of the dark-halos, in agreement with the observed behaviour.