Evolution of barred spiral galaxies and chemical enrichment processes of galaxies and their environment

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The proposed research program is divided in two separate components. The first component is a numerical study of the formation and evolution of barred spiral galaxies. During the last five years, we have conducted detailed numerical studies of the evolution of isolated barred galaxies, focusing on the dynamics, the history of star formation and chemical enrichment, and the effect of AGN feedback. We only considered the secular evolution of galaxies, by ignoring interactions with their surroundings. In the next phase, we will study the impact of external processes such as IGM accretion, external tidal fields, and ram pressure stripping. These processes can greatly affect the evolution of the galaxies, by increasing or depleting the supply of gas available for forming stars and feeding the central AGN, and by destroying or reforming a bar, with major consequences for the dynamics of gas flows in the galaxies. The ultimate goal of this long-term program is to understand the physical principles that determine the history of star formation and chemical enrichment in barred galaxies, explain the correlation (or lack of) between the presence and strength of bars, enhanced star formation and enhanced metallicity, and determine the role played by feedback and external processes in trigerring or quenching star formation in barred galaxies.The second component consists of studying the chemical enrichment processes of galaxies and their environment. Our objective is to better understand the formation and evolution of galaxies in general by using different observables/tracers, with the goal to converge toward a coherent and consistent picture of galaxies and intergalactic medium (IGM) evolution. For this purpose, we have developed an innovative numerical algorithm that can simulate concurrently the evolution of galaxies and the IGM, and their mutual interactions. In the next phase, we will use this algorithm to reproduce the distribution and properties of galaxies and the structure of the IGM from redshift 6 to the present. We will then produce a database of synthetic absorption spectra of high-redshift quasars, and compare these synthetic spectra with recent observations of DLAs. This will provide statistics for the properties of galaxies (mass, redshift, evolutionary state, environment), as a function of the chemical signatures in the spectra. Using the same database, we will study the various mechanisms responsible for the chemical enrichment of the IGM (galactic winds, ram pressure stripping, tidal disruption, ...). The objective is to determine the relative contribution of these processes, and their dependence on redshift or environment (galaxy clusters vs. field). In a separate project, we will generate synthetic integrated spectra of galaxies, to be compared with observations. The goal is to determine if these observations can be used as a tracer of galaxy evolution.