  Measurements from galaxies spanning a broad range of morphology reveal a
linear scaling of enclosed dark to luminous mass that is not anticipated by
standard galaxy formation cosmology. The linear scaling is found to extend from
the inner galactic region to the outermost data point. Uncertainties in the
linear relation are narrow, with rms = 0.31 and {\sigma} = 0.31. It is unclear
what would produce this linearity of enclosed dark to luminous mass. Baryonic
processes are challenged to account for the linear scaling, and no dark matter
candidate possesses a property that would result in a linear relation. The
linear scaling may indicate new dark matter candidates, or an astrophysical
process beyond the standard galaxy formation theory.
