GEPI

De la conception instrumentale
à l’exploitation des observables

Assembling the Milky Way

Florent Renaud, Lund Observatory, Sweden

In the Gaia era, and with more and more complete and detailed surveys, the assembly of the Milky Way is being scrutinized with an always increasing accuracy. The kinematic and chemical properties of stellar populations are analyzed with the aim of reconstructing the formation history of the Galaxy. In this context, a major topic of interest is the role of galaxy mergers in driving the observed diversity of stellar populations. A number of simulations and models are being developed with the aim of retrieving these properties, and proposing a formation scenario of our galaxy. In this talk, I will introduce VINTERGATAN, a new cosmological zoom-in simulation of a Milky Way-like galaxy. I will use it to present a detailed analysis of the signatures of mergers in the chemical abundances of the stellar populations, as opposed to in situ formation and intrinsic evolution. I will particularly present a new scenario for the simultaneous formation of the outer and inner thin disks at different metallicities. Finally I will discuss the mechanisms that allow for the transition between chemically, kinematically and structurally distinct disks.