Evolution of the chemical properties of Milky Way type galaxies in a hierarchical L-CDM scenario

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

Scientific Contributions book of the First La PLata International School on Astronomy and Geophysics: Compact Objects and their Emission

PAIDEIA

Lugar: La Plata, Buenos Aires, Argentina; Año: 2009; p. 103 - 107

We studied the formation and chemical evolution of a sample of Milky Way type galaxies selected from the public database of the Millennium simulation. We found that Milky Way type galaxies in this model may be described by a main progenitor which evolves accreting smaller systems. Only 9 % of the total sample suffers stellar major mergers along their formation paths. We compare this evolution with that of giant elliptical galaxies and dwarf irregular systems extracted from the same catalogue finding strong differences in their assembly histories. The percentage of stellar mass at z=0 coming from accretions ranges from 0 in the case of dwarf irregulars to approximately 50% for giant ellipticals, while for MilkyWay type galaxies it is around 15%. These different accretion histories affect the gas consumption and the star formation processes in the main progenitors of the systems leading to very different chemical evolution.