Dark-Matter Distribution inferred from High-accuracy Rotation Curves

Abstract

Using high-accuracy rotation curves of spiral galaxies, we derive distributions of the surface mass density. Comparing with the luminosity profiles, we show that the dark mass in disk and bulge distributions follows those of luminous (stellar) mass, while luminous mass in halos does not follow dark mass. The dark-mass fraction (DMF) increases with the radius in the disk, and rapidly toward edge in the halo. In some galaxies, DMF increases toward the center,