Final Report Summary - NEOGAL (New frOntiers in Galaxy spectrAl modeLing) NEOGAL has been an intensive, coordinated effort to explore the early chemical evolution of galaxies through the development of an innovative set of spectral analysis tools. This was achieved through the accomplishment of four interdisciplinary projects using state-of-the-art techniques:1. The development of a new approach overcoming the limitations of exiting methods, to measure the chemical composition of ionized gas with unknown heavy element abundance ratios in high-redshift galaxies;2. The combination of this approach with sophisticated models of the ultraviolet emission from young stellar populations and active galactic nuclei, accounting also for interstellar absorption, to allow differentiated constraints on the chemical composition of stars and gas and the nature of ionizing sources in galaxies; 3. The combination of these models with cosmological simulations of galaxy formation, to identify spectral signatures of star formation and black-hole growth, and competing scenarios of early chemical evolution, in observations of statistical samples of high-redshift galaxies;4. The development of a new-generation tool to allow the astronomical community at large to exploit these models to interpret observations of distant galaxies.The successful achievement of these projects has led to the elaboration of an innovative, highly flexible tool, named BEAGLE, to model and interpret any combination of photometric and spectroscopic galaxy spectral energy distribution in terms of physical parameters. A most original feature of this versatile tool is the possibility for astronomers to interpret simultaneously the continuum and line emission from a galaxy and constrain, in a rigorous statistical way, the main properties of stars, different phases of the interstellar medium, and soon the contribution to the emission by an active galactic nucleus and radiative shocks. The tool also enables the derivation of population-wide galaxy parameters through hierarchical Bayesian modeling. These models are proving extremely useful in designing future surveys of primeval galaxies that will be carried out with the next generation of large facilities, such as the James Webb Space Telescope and the European Extremely Large Telescope.
