Current velocity data on dwarf galaxy NGC1052-DF2 do not constrain it to
  lack dark matter
  It was recently proposed that the globular cluster system of the very low
surface-brightness galaxy NGC1052-DF2 is dynamically very cold, leading to the
conclusion that this dwarf galaxy has little or no dark matter. Here, we show
that a robust statistical measure of the velocity dispersion of the tracer
globular clusters implies a mundane velocity dispersion and a poorly
constrained mass-to-light ratio. Models that include the possibility that some
of the tracers are field contaminants do not yield a more constraining
inference. We derive only a weak constraint on the mass-to-light ratio of the
system within the half-light radius (M/L_V<6.7 at the 90% confidence level) or
within the radius of the furthest tracer (M/L_V<8.1 at the 90% confidence
level). This limit may imply a mass-to-light ratio on the low end for a dwarf
galaxy but many Local Group dwarf galaxies fall well within this contraint.
With this study, we emphasize the need to reliably account for measurement
uncertainties and to stay as close as possible to the data when determining
dynamical masses from very small data sets of tracers.
