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L1: Stellar Spectral Analysis

We develop methods to determine chemical composition in stars. ERIS attributes the chemical abundances imprinted in stellar atmospheres as the heritable marker for the phylogenetic signal of galaxy evolution. The problem of determining stellar atmospheric parameters (effective temperature, surface gravity, overall metallicity, etc), and subsequently determining individual chemical abundances, is complex. Despite the rapid development of better and more efficient algorithms, and the availability of improved stellar spectra (higher resolution, wider spectral coverage, higher signal-to-noise ratio), typical statistical errors in the measured parameters and abundances have proven difficult to reduce beyond certain minimum values. In this context, working on the improvement of these methods, and in particular, ensuring that the results have internal consistency, is important in view of using these stellar chemical abundances for constructing phylogenetic trees whose topology is supported by the information used to build them. We aim to unravel, based on the subtle signals contained in the chemical composition of stars, the history of the Galaxy. Therefore, the work we are conducting in stellar spectroscopy is of fundamental importance to minimize measurement errors and ensure the consistency of results obtained by various techniques or spectral information in different ranges (optical/infrared) as well as with chemical evolution models.