Recent star formation episodes in the Galaxy: Impact on its chemical properties and the evolution of its abundance gradient

Abstract

Aims. We investigate the chemical evolution of the Milky Way disc exploring various schemes of recent (past several Gyr) star formation episodes, as reported in recent observational works. Methods. We used a semi-analytical model with parametrized radial migration, and we introduced Gaussian star formation episodes constrained by the recent observations. Results. We find significant impact from the star formation episodes on several observables, including the local age–metallicity and [α/Fe] versus metallicity relations, as well as the local stellar metallicity distribution and the existence of young [α/Fe] -rich stars. Moreover, we show that the recently found 'wiggly' behaviour of the disc abundance gradient with age can be interpreted in terms of either star formation or infall episodes.