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 the total to visible mass and various parameters describing the evolution and environment of the galaxies. Using the relative velocities of the Hα emission line across the galaxy’s surface to measure the rotation curve of each galaxy, we estimate the 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 find that faint galaxies with low metallicities, typically in the blue cloud, have the highest ratios of total to visible mass. Those galaxies which 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. The galaxies with the lowest ratios of total to visible mass are intermediate in both metallicity and absolute magnitude. We introduce a parameterization that predicts a galaxy’s ratio of total to visible mass based on its photometry and absolute magnitude.