Galactic chemical evolution in hierarchical formation models

PhD ceremony: Mr. M. Arrigoni, 11.00 uur, Academiegebouw, Broerstraat 5, Groningen

Thesis: Galactic chemical evolution in hierarchical formation models

Promotor(s): prof. S.C. Trager

Faculty: Mathematics and Natural Sciences

With the advent of more powerful telescopes and detectors, precise observations of chemical abundances and abundance ratios in various phases (stellar, ISM, ICM) offer the opportunity to obtain strong constraints on galaxy formation histories and the physics that shapes them. However, in order to take advantage of these observations, it is necessary to implement detailed modeling of chemical evolution into a modern cosmological model of hierarchical assembly. In this work we use the semi-analytical approach to incorporate detailed chemical evolution into a ΛCDM galaxy formation model, taking into account enrichment by SNe Ia, SNe II and long-lived stars, and abandoning the instantaneous recycling approximation by considering the finite lifetimes of stars of all masses. The delay in the metal enrichment by SNe Ia is calculated self-consistently according to the Delay-Time-Distribution (DTD) formalism. The base model includes gas inflows due to radiative cooling of gas and outflows due to supernova and AGN-driven winds, as well as triggered star formation and morphological transformation of galaxies via mergers, hierarchical clustering of dark matter halos, the growth of supermassive black holes, the evolution of stellar populations, and the effects of dust obscuration. Overall the new model simultaneously produces acceptable predictions for the chemical properties of galaxies in the local Universe and the ICM in nearby clusters, as well as the evolution of the mass–metallicity relation upto redshift of approximately 2.