Back to Volume
Paper: Scaling laws for dark matter in late-type galaxies
Volume: 10, Evolution of the Universe of Galaxies: Edwin Hubble Centennial Symposium
Page: 33
Authors: Kormendy, John
Abstract: Published mass models fitted to galaxy rotation curves are used to study the systematic properties of dark matter (DM) halos. DM in Sc - Im galaxies satisfies well-defined scaling laws: halos in less luminous galaxies have smaller core radii, higher central densities, and higher central velocity dispersions. These correlations provide new constraints on the nature of DM and on galaxy formation and evolution. For example: (1) Galaxies are increasingly dominated by dark matter at lower luminosities. In the smallest dwarfs, the visible matter is almost negligible. There may exist a population of dwarf halos that are completely dark; (2) The surprisingly high DM densities found in the dwarf spheroidal galaxies Draco and UMi by Aaronson and Olszewski are nearly normal for galaxies of such low luminosity. These appear to be real galaxies and not just tidal fragments. (3) The correlation between central density and velocity dispersion (the 'cooling diagram') is consistent with baryonic DM.
Back to Volume