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Our Milky Way surrounded by disrupted satellites and globular clusters. Image credit: James Josephides and S5 Collaboration

Accreted stellar populations are comprised of the remnants of destroyed galaxies, and often dominate the 'stellar haloes' of galaxies such as the Milky Way. This ensemble of external contributors is a key indicator of the past assembly history of a galaxy. The ratio of stars belonging to different evolutionary phases within a stellar population is sensitive to the total stellar mass of the parent system. In this project you will use red giant branch (RGB), blue horizontal branch (BHB) and blue straggler (BS) stars belonging to dwarf galaxies and globular clusters, and compare these counts to those of the Milky Way stellar halo. The BS-to-BHB and BS-to-RGB will be used as diagnostics to constrain the size of the building blocks that came together to form the Milky Way halo.