On the persistence of two small-scale problems in {\Lambda}CDM
  We investigate the degree to which the inclusion of baryonic physics can
overcome two long-standing problems of the standard cosmological model on
galaxy scales: (i) the problem of satellite planes around Local Group galaxies,
and (ii) the "too big to fail" problem. By comparing dissipational and
dissipationless simulations, we find no indication that the addition of
baryonic physics results in more flattened satellite distributions around
Milky-Way-like systems. Recent claims to the contrary are shown to derive in
part from a non-standard metric for the degree of flattening, which ignores the
satellites' radial positions. If the full 3D positions of the satellite
galaxies are considered, none of the simulations we analyse reproduce the
observed flattening nor the observed degree of kinematic coherence of the Milky
Way satellite system. Our results are consistent with the expectation that
baryonic physics should have little or no influence on the structure of
satellite systems on scales of hundreds of kiloparsecs. Claims that the "too
big to fail" problem can be resolved by the addition of baryonic physics are
also shown to be problematic.
