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Dwarf galaxies in groups of galaxies provide excellent test cases for models of structure formation. This led to a so-called small-scale crisis, including the famous missing satellite and too-big-to-fail problems. It was suggested that these two problems are solved by the introduction of baryonic physics in cosmological simulations. We test for the nearby grand spiral M83 - a Milky Way sibling - whether its number of dwarf galaxy companions is compatible with today's + Cold Dark Matter model using two methods: with cosmological simulations that include baryons, as well as with theoretical predictions from the sub-halo mass function. By employing distance measurements we recover a list of confirmed dwarf galaxies within 330 kpc around M83 down to a magnitude of MV =-10. We found that both the state-of-the-art hydrodynamical cosmological simulation Illustris-TNG50 and theoretical predictions agree with the number of confirmed satellites around M83 at the bright end of the luminosity function (>10⁸ solar masses) but underestimate it at the faint end (down to 10⁶ solar masses) at more than 3 and 5 levels, respectively. This indicates a too-many satellites problem in CDM for M83. The actual degree of tension to cosmological models is underestimated, because the number of observed satellites is incomplete due to the high contamination of spurious stars and galactic cirrus.
Müller et al. (Wed,) studied this question.