Program: GN-2020B-Q-118

The satellite systems of the Milky Way and Andromeda have proved extremely fruitful testing grounds for our concordance cosmology model. However, to fully understand small-scale structure, it is crucial to characterize a statistical sample of satellite systems around other MW-like galaxies. We have developed and tested machinery to use surface brightness fluctuations (SBF) to obtain distances to low mass satellites, allowing us to characterize satellite systems much more efficiently than previously possible. Using this, we have started a survey with the long term goal of characterizing the satellites of all massive hosts in the Local Volume down to dwarf luminosities of $M_V<-9$ mag. In the early results of the survey, we see hints that many of the satellite systems are more centrally concentrated than expected from simulations. However, to robustly characterize this, it is important to survey other satellite systems of hosts with a range of properties. To continue the survey, we have used shallow ground based imaging to identify candidate satellites around three nearby hosts that bracket the MW in various properties. We propose to use Gemini/GMOS to acquire deeper images of these candidates to measure SBF distances and classify each dwarf as either a satellite of its host or a background contaminant. With this data, we will completely characterize the satellite systems of these hosts out to 300 kpc projected from the host, doubling the number of hosts surveyed at this level.