36) How Unusual is the Milky Way's Assembly History?

Abstract: The most recent massive merger event experienced by the Milky Way (MW) halo was the accretion of the Large Magellanic Cloud (LMC). Recent analyses of galactic stellar data from the Gaia satellite have uncovered an earlier massive accretion event, the Gaia-Enceladus-Sausage (GES), which merged with the MW around 10 Gyr ago. This talk will consist of two parts. In the first part of this talk we use the EAGLE simulation to study properties of simulated MW-mass haloes constrained to have accretion histories similar to that of the MW, specifically the recent accretion of an ‘LMC’ galaxy and a ‘GES’ merger. I will present the criteria for our selections and the properties of our subsamples of MW-like galaxies with similar assembly histories to our Galaxy. In the second part of this talk I will discuss how the progenitors of MWs with this specific assembly will differ from that of an average MW-like progenitor in high redshift observations using JWST.

Bio: Hi everyone! I’m Tilly Evans, I’m from a small town in West Wales and I am currently a PhD student at Durham University studying galactic archaeology under the supervision of Alis Deason, Azadeh Fattahi and Carlos Frenk. Before arriving in Durham I achieved a First Class Honours in Astrophysics in an undergraduate masters (MPhys) degree at Cardiff University (2015-2019).