Reconstructing the merger trees and tracking the assembly histories of MW-like halos in the ARTEMIS simulations

GRIMOZZI, SALVADOR E.; FONT, ANDREEA S.; DE ROSSI, MARÍA EMILIA

Encuentro; Challenges and Innovations in Computational Astrophysics V; 2023

Two populations of dwarf galaxies can be associated with the Milky Way. The “surviving” satellites that orbit it in the present time and the “disrupted” ones that were accreted by it and whose debris now are part of the stellar halo. We studied the stellar MZR and the stellar [Mg/Fe] abundances of disrupted and surviving dwarfs of simulated Milky Way mass haloes in ARTEMIS, a suite of 42 zoomed-in cosmological hydrodynamical simulations. We also were able to trace a connection between them and their merger histories. We developed efficient techniques to study the assembly of haloes, track the evolution of the dwarfs and characterize their environment. Some of these techniques include the reconstruction and analysis of each halo’s merger tree. We successfully identify a strong correlation between the stellar metallicity (Z_*, measured by the stellar [Fe/H] abundances) and the stellar mass (M_*) in both populations of satellites. We found that higher-mass satellites tend to show lower stellar [Mg/Fe] than those in the low mass range, which is consistent with observational data from the MW. At fixed stellar mass, disrupted dwarfs are more metally enriched and more alpha-enhanced (i.e. present higher stellar [Mg/Fe]) than their surviving counterparts. We found that these differences are influenced by the accretion times of disrupted dwarfs and by the different environments where both populations evolved.