Gaia-ESO Survey abundances radial distribution

The adopted chemo-dynamical model, with the new generation of metallicity-dependent stellar yields for massive stars, is able to reproduce the observed spatial distributions of abundance ratios, in particular the abundance ratios of [O/Fe] and [Mg/Fe] in the inner disc (5kpc<R_GC_<7kpc), with their differences, that were usually poorly explained by chemical evolution models. Oxygen and magnesium are often considered to be equivalent in tracing {alpha}-element abundances and in deducing, for example, the formation timescales of different Galactic stellar populations.

In addition, often [{alpha}/Fe] is computed combining several {alpha}-elements. Our results indicate, as expected, a complex and diverse nucleosynthesis of the various {alpha}-elements, in particular in the high metallicity regimes, pointing towards a different origin of these elements and highlighting the risk of considering them as a single class with common features.