Assessing the chemical evolution of galaxies with large spectral surveys and spatially resolved observations

Galaxies continuously undergo chemical enrichment. Heavy elements are produced in stars during their lifetime and then dispersed by means of stellar winds and supernovae, contributing to the enrichment of the surrounding interstellar medium (ISM). Gas flows, including inflows from the cosmic web and supernovae- or AGN-driven outflows, also play a crucial role in the definition of the chemical enrichment level by acting as regulators of both the gas content and the amount of metals that galaxies are capable to retain in the gas-phase of the ISM. Therefore, the gas-phase metallicity represents a fossil record of the recent star formation history of a galaxy and is strongly sensitive to all the physical processes which shape and drive the baryon-cycle in the Universe. Indeed, this mutual correlation between stellar activity, mass growth, metal production and gas flows gives rise to the well established scaling relations between mass, metallicity and star formation rate observed and thoroughly investigated both in the local Universe and at higher redshifts, whose characterization can provide crucial constraints on models and simulations aimed at describing how galaxies evolve across the epochs. In this thesis we address some of the currently most debated topics related to the chemical evolution of star forming galaxies, by means of statistically robust analysis of large samples of local objects from the Sloan Digital Sky Survey (SDSS) and of near- infrared, spatially resolved spectroscopy of high-redshift sources, obtained from new generation instruments like KMOS on the Very Large Telescope and ARGOS on the Large Binocular Telescope.