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

Abstract

We investigate the chemical evolution of the Milky Way disc exploring various schemes of recent (last several Gyr) star formation episodes, as reported in recent observational works. We use a semi-analytical model with parametrized radial migration and we introduce gaussian star formation episodes constrained by those recent observations. We find significant impact of the star formation episodes on several observables, like the local age-metallicity and [alpha/Fe] vs metallicity relations, as well as the local stellar metallicity distribution or the existence of young [alpha/Fe]-rich stars. Moreover, we show that the recently found "wiggly" behaviour of the disk abundance gradient with age can be interpreted in terms of either star formation or infall episodes.

15 pages, 7 figures, Astronomy and Astrophysics, in press