Evolution of the Milky Way halo by accretion of dwarf satellite galaxies

TL;DR

This paper models the chemo-dynamical evolution of dwarf satellite galaxies in the Milky Way's halo, exploring how hierarchical merging and accretion shape the stellar halo's chemical and kinematic properties.

Contribution

It presents a new chemo-dynamical simulation of satellite accretion based on cosmological Via Lactea II data, linking hierarchical merging to halo formation.

Findings

Satellite accretion influences halo chemical composition

Kinematic coherence of halo stars can result from accretion events

Simulations reproduce observed properties of the Milky Way halo

Abstract

Within the Cold Dark Matter scenario the hierarchical merging paradigm is the natural result to form massive galactic halos by the minor mergers of sub-halos and, by this, inherently their stellar halo. Although this must be also invoked for the Milky Way, the context of chemical and kinematic coherence of halo stars and dwarf spheroidal galaxies is yet unsolved a focus of present-day research. To examine this issue we model the chemo-dynamical evolution of the system of satellites selected from the cosmological Via Lactea II simulations to be similar for the Milky Way environment but at an early epoch.