Do Elliptical Galaxies Have Dark Matter?
M. Loewenstein (NASA/GSFC), R. E. White III (U. Alabama) Analyzing the relationship between X-ray temperature and velocity dispersion in an optically complete sample of elliptical galaxies recently derived by Davis amp; White, we demonstrate that L>L_* galaxies contain substantial amounts of dark matter in general. We also present constraints on the dark matter scale length and on the dark-to-luminous mass ratio both within the optical half-light radius and for the entire galaxy. Our results can be consistently embedded within a standard CDM scenario for structure formation, but only if elliptical galaxies have suffered substantial mass loss with less massive systems losing progressively more mass.
