Deciphering the formation & structure of the Milky Way from chemo-dynamics and cosmological simulations

Francesca Fragkoudi

MPA Garching

Embedded in the chemo-dynamical properties of stellar populations in the inner Milky Way (MW), are clues to the formation history of our Galaxy. By combining these properties with tailored N-body simulations of a pure disc galaxy, we show that the MW bulge likely has a secular in-situ disc origin - i.e. that the MW bulge is a buckled bar, made up of the thin and thick discs. I will show recent results from state-of-the-art cosmological simulations, which lend further support to the in-situ formation scenario of the Milky Way bulge, and which place constraints on the merger history of our Galaxy, as well as on the mass ratio of the recently proposed Gaia-Enceladus-Sausage merger. Finally, I will discuss the effects of bars on their host discs in cosmological simulations, in the context of the phase-space perturbations revealed in the MW disc by Gaia DR2.