The Physical Properties of the Accreted Satellites of the Milky Way.

Lead Research Organisation: Liverpool John Moores University
Department Name: Astrophysics Research Institute

Abstract

The aim of this project is to investigate the properties of dwarf galaxies that were accreted onto the Milky Way and today make up a substantial mass fraction of the stellar mass budget of its halo. The main properties of interest are mass, baryonic history (i.e., star formation and chemical enrichment histories) and accretion time of dwarf galaxies. Mackereth et al (2019) studied these properties of accreted satellites of Milky Way-like galaxies in the Evolution and Assembly of GaLaxies and their Environments (EAGLE) simulations and suggested that the masses of these satellites are strongly correlated with their stellar abundance patterns in the alpha-iron plane. We will further explore the dependence of chemistry on mass and other parameters, such as the history of interaction with the central halo, particle binding energy and accretion time with the goal of probing theoretical connections between chemical properties and baryon histories in EAGLE. In the next stage of the project the knowledge acquired from studying the EAGLE simulations will be employed in order to characterise the properties of accreted satellites that make up the Milky Way halo and applied to data from the APOGEE and WEAVE surveys. The sample of interest will be selected on the basis of analysis techniques developed in-house to determine the orbital properties and structural parameters of galactic components after correction for survey selection effects. Ultimately, comparison between the chemodynamic properties of ~10^6 Halo stars and EAGLE predictions will enable a complete characterisation of the properties of the stellar populations that comprise the Milky Way's halo.

Publications

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