1999ApJ...524L..15G

The empirical relation of coupling in M_d=γM^1/2r between the halo dark mass distribution M_d and visible mass M at radius r, previously shown in spiral galaxies and in the core of MS 2137-2353, is tested for the inner 150 h^–1 kpc Virgo Cluster core. If the stellar mass-to-light ratio in M87 is treated as a free parameter, the density distribution predicted by this relation is found to be consistent with that derived from published surface photometry, stellar and globular cluster dynamics, and X-ray observations. The best fit is obtained for Υ_*(M87)=6 (M/L_B)_☉, but a wide range of stellar mass-to-light ratios are possible. At r>50 kpc, the relation of coupling and the equation of dynamical equilibrium of the gas are the same. The extrapolated dark mass is also consistent with the kinematics of early-type galaxies on a larger, megaparsec scale for Υ_*(M87)=8-11 (M/L_B)_☉. The cluster dark mass halo and the stellar mass in M87 have equal weight at ∼1/2-3/4 effective radius.