Galactic Mass-to-Light Ratios With Superfluid Dark Matter
  We make rotation curve fits to test the superfluid dark matter model. Our aim
is to investigate whether superfluid dark matter provides satisfactory fits to
galactic rotation curves with reasonable stellar mass-to-light ratios. We
fitted the superfluid dark matter model to the rotation curves of 169 galaxies
in the SPARC sample. We found that the mass-to-light ratios obtained with
superfluid dark matter are generally acceptable in terms of stellar
populations. However, the best fit mass-to-light ratios have an unnatural
dependence on the size of the galaxy in that giant galaxies have systematically
lower mass-to-light ratios than dwarf galaxies. A second finding is that the
superfluid often fits the rotation curves best when the superfluid's force does
not closely resemble that of Modified Newtonian Dynamics (MOND). In that case,
we can no longer expect superfluid dark matter to reproduce the
phenomenologically observed scaling-relations that make MOND appealing. If, on
the other hand, we consider only solutions whose force approximates MOND well,
then the total mass of the superfluid is in tension with gravitational lensing
data. We conclude that even the best fits with superfluid dark matter are still
unsatisfactory.
