The MUSE-Faint Survey:  A survey of ultra-faint galaxies with MUSE

Galaxy assembly occurs on all scales, with the very smallest scales being particularly important at the highest redshifts. A subset of the very first galaxies that survived until the present day can be found nearby. They are known as Ultra-Faint Dwarfs (UFDs). UFDs are essential as relics of the time of reionization and also because they provide excellent laboratories for studying star formation and feedback in the feeblest halos. They are ideal for placing constraints on dark matter models, given that dark accounts for up to 99% of their total mass. They represent the extreme low-mass end of galaxy assembly. UFDs, however, are challenging to study because of their low number of stars and low contrast against the background. Here, we present an overview of the MUSE-Faint Survey, a survey of ultra-faint galaxies using MUSE IFU data. Using stellar line-of-sight velocities we made the first measurements of the binary fractions, model density profiles and investigated the presence of dark matter cores and solitons in these systems. We calculated masses, concentrations, and circular velocities from the profiles, allowing us to constrain tidal stripping effects. Our findings ruled out the presence of dark matter cores as large as those of more massive dwarf galaxies and suggested that the galaxies had not undergone significant tidal stripping within their half-light radii. In this contribution we propose to discuss these and other results from the MUSE-Faint Survey.