  Cosmological simulations of galaxy formation predict a universal form for the
mass profile of dark matter (DM) halos from cluster to galaxy scales.
Remarkably few interesting constraints exist, however, on DM halos in
early-type galaxies. Using Chandra we present the temperature, density and mass
profiles of a small sample of early-type galaxies, revealing significant DM in
each case. When a component is included to account for stellar mass and the DM
halo is allowed to respond adiabatically to the baryonic condensation into
stars, the mass profiles are well-fitted by the universal profile, with Virial
masses and concentrations in agreement with simulations. However, only ~half,
or less, of the mass within R_e seems attributable to the stars, implying
stellar M_*/L_B ~1-5.
