The Milky Way experienced several merger events which left their imprints on the stellar halo. In particular, it is known that a major merger happened during the Galaxy’s first Gyrs and, likely, perturbed its disc-shape structure. In order to fully understand the effects of such an event, we need to know the chemical and dynamical characteristics of the young Milky Way, i.e. before the major merger event, and the accreted satellite. For this purpose, we are developed the Gaia-EncelAdus-Sausage Timing, chemistRy and Orbit (GASTRO) library: a suite of SPH + N-body models to explore formation scenarios of Milky Way-like galaxies that went through similar accretion events. Such idealized models enable us to control the initial conditions of the merger and which physical processes are included, therefore understanding them better. In this talk, I use a subset of the GASTRO library and explore the chemodynamical properties of the accreted stars. I show that single merger events spread over a large range in the energy-angular momentum plane and also have a rich chemical signature in the dynamical space. These allow us to reconcile some substructures in the Milky Way stellar halo to a single merger event.
