Dependence of the ratio of total to visible mass on observable
  properties of SDSS MaNGA galaxies
  Using spectroscopic observations from the SDSS MaNGA DR15, we study the
relationships between the ratio of total to visible mass and various parameters
characterizing the evolution and environment of the galaxies in this survey.
Measuring the rotation curve with the relative velocities of the H-alpha
emission line across the galaxy's surface, we estimate each galaxy's total
mass. We develop a statistical model to describe the observed distribution in
the ratio of total to visible mass, from which we extract a galaxy's most
probable value for this mass ratio. We present the relationships between the
ratio of total to visible mass and several characteristics describing galactic
evolution, such as luminosity, gas-phase metallicity, distance to the nearest
neighbor, and position on the color-magnitude diagram. We find that faint
galaxies with low metallicities, typically in the blue cloud, have the highest
ratios of total to visible mass. Those galaxies that exhibit the second highest
ratios of total to visible mass are the brightest with high metallicities,
typically members of the red sequence or green valley. AGN activity is likely
both the quenching mechanism and the feedback that drives the mass ratio higher
in these massive galaxies. Finally, we introduce a parametrization that
predicts a galaxy's ratio of total to visible mass based on its photometry and
luminosity.
