Are Milky-Way dwarf-spheroidal galaxies dark-matter free?
  We have found that the high velocity dispersions of dwarf spheroidal galaxies
(dSphs) can be well explained by Milky Way (MW) tidal shocks, which reproduce
precisely the gravitational acceleration previously attributed to dark matter
(DM). Here we summarize the main results of Hammer et al. (2019) who studied
the main scaling relations of dSphs and show how dark-matter free galaxies in
departure from equilibrium reproduce them well, while they appear to be
challenging for the DM model. These results are consistent with our most recent
knowledge about dSph past histories, including their orbits, their past star
formation history and their progenitors, which are likely tiny dwarf irregular
galaxies.
