The ΛCDM cosmology predicts the hierarchical nature of structure formation. Galaxies across all mass scales are expected to have substructures populating their halos as a signature of this, pointing to a close link between a host galaxy and its substructures. They can inform us about the accretion history and various physical properties of their host. Searching for these substructures is crucial in helping us to understand the greater story of the galaxies we observe and how they formed and evolved.

I present the discovery of a candidate globular cluster (GC) system around the relatively isolated dwarf irregular galaxy IC 2574. I measure the photometric properties of the individual GCs and confirm a high-luminosity, massive ω Cen GC analogue, with an otherwise normal GC population. I find evidence of colour bimodality in the GC system, which could imply two subpopulations with distinct formation scenarios. Spectroscopy of these candidates will confirm their membership to IC 2574 and help us to understand IC 2574’s evolution. I measure the halo mass of IC 2574 and place it on the remarkably linear GC system mass-halo mass relation, finding that it agrees excellently.

This GC system mass-halo mass relation is well populated in the high-mass regime, but is less understood in the low-mass regime where the onset of stochastic GC occupation in galaxies occurs. I search three lower mass galaxies for new GC candidates to populate the low-mass regime. I find young star clusters in IC 1613 and VV 124, which are important as they are believed to be progenitors of GCs. I find two GC candidates in F8D1 in addition to a known GC candidate. F8D1 agrees well with the GC system mass-halo mass relation as it stands currently with incomplete spatial coverage. With wide-field and deeper imaging surveys, searching for GC candidates in the full halos of lower mass galaxies will allow us to populate the low-mass regime of this relation and address the broader questions it answers for GC formation, and the host galaxy’s formation and evolution.

Finally, I present the analysis of the structural parameters of a newly discovered ultra-faint dwarf (UFD) galaxy Pisces VII, which is highly likely to be the second satellite galaxy around Triangulum. Pisces VII appears to have an interesting feature of young blue stars that could indicate recent star formation in a UFD, unusual to our expectations of these systems being quenched by reionization. Confirming this could help us to understand the role of the environment of the host galaxy in the evolution of UFDs, which are exciting laboratories for galaxy formation physics and the nature of dark matter.