GASTRO library I: the simulated chemodynamical properties of several GSE-like stellar halos

Understand

The Milky Way stellar halo contains relics of ancient mergers that tell the story of our Galaxy's formation.

• Some of them are identified due to their similarity in energy, actions and chemistry, referred to as the "chemodynamical space", and are often attributed to distinct merger events.
• It is also known that our Galaxy went through a significant merger event that shaped the local stellar halo during its first Gyr.
• Previous studies using $N$-body only and cosmological hydrodynamical simulations have shown that such single massive merger can produce several "signatures" in the chemodynamical space, which can potentially be misinterpreted as distinct merger events.