A shallow dark matter halo in Ultra Diffuse Galaxy AGC 242019: are UDGs
  structurally similar to low surface brightness galaxies?
  A central question regarding Ultra Diffuse Galaxies (UDGs) is whether they
are a separate category to Low Surface Brightness (LSB) galaxies, or just their
natural continuation towards low stellar masses. In this letter, we show that
the rotation curve of the gas rich UDG AGC 242019 is well fit by a dark matter
halo with inner slope that asymptotes to -0.54, and that such fit provides a
concentration parameter that matches theoretical expectations. This finding,
together with previously works in which shallow inner profiles are derived for
UDGs, shows that the structural properties of these galaxies are like other
observed LSBs. UDGs show slowly rising rotation curves and this favours
formation scenarios in which internal processes, such as SNae driven gas
outflows, are acting to modify UDGs profiles.
