Chemical evolution of galaxies in the Millennium Simulation: comparison between the properties of dwarf irregular, massive elliptical and Milky-Way type galaxies

DE ROSSI, MARÍA EMILIA; TISSERA, PATRICIA BEATRIZ; DE LUCIA, GABRIELLA; KAUFFMANN, GUINEVERE

Malargüe, Mendoza, Argentina

Congreso; Reunión Anual de la Asociación Argentina de Astronomía Nro. 50; 2007

Asociación Argentina de Astronomía

We employ galaxy catalogues from the Millennium Simulation to study the chemical enrichment histories of Milky Way type galaxies in a hierarchical scenario. Our results suggest that these systems may be described by a main progenitor which evolves from z= 5 to z = 0 whithout suffering significant merger events. More than 80% of their present stellar mass has been formed in the main progenitor and only around 10% of the sample has suffered a major merger in their lives. The chemical evolution of these galaxies seems to be driven mainly by the gas consumption and collapse history of the main progenitors. Comparing these results with those obtained for a sample of dwarf irregular and massive elliptical systems selected from the same catalogue, we encountered that the formers are made of systems which evolve passively accreting negligible mass, while in the case of massive elliptical galaxies, more than 50% their stellar mass at z = 0 comes from accretions. In this paper, we study the implications of these different assembly histories on the chemical evolution.