Constraining the Dark Matter Mass Profiles of Nearby Elliptical Galaxies

Using velocity dispersion data, we constrain the Burkert dark matter (DM) mass profiles of 20 nearby elliptical galaxies observed in the MASSIVE survey out to R_max/R_eff > 1.5. We show that the best-fit values of the DM core radius (r₀) and core density (ρ₀) parameters are strongly correlated with the effective radii of these galaxies, R_eff. We further show that similar R_eff correlations extend to multiple galaxy types over many orders of magnitude in galaxy mass and luminosity.