Clues to the formation of Galactic structure from cosmological hydrodynamical simulations
Rob Grand (IAC - Tenerife)
Tuesday 22/03/2022 @ 14:00, Remote talk
The confluence of large-scale, precision Galactic surveys such as Gaia, and high resolution cosmological hydrodynamical simulations of Milky Way-mass galaxies provides an excellent opportunity to understand the assembly and evolution of the Galaxy. In this talk, I will highlight several insights from such simulations into the properties of the Gaia-Enceladus-Sausage (GES) progenitor - the Galaxy’s putative last significant merger - and its impact on the formation of the inner stellar halo and thick disc. We also find tentative evidence that the GES merger stimulated the formation of the Galactic bar, but that this can only occur if the merger ratio is sufficiently small. I will discuss how this early phase of merger-dominated evolution transitions to a quiet phase dominated by secular evolution and steady gas accretion, but that still may require outside influence to create the famous chemical thin/thick disc dichotomy. Finally, I will discuss these results in the context of our current knowledge and future directions.