Dark halo structure in the Carina dwarf spheroidal galaxy: joint
  analysis of multiple stellar components
  Photometric and spectroscopic observations of the Carina dSph revealed that
this galaxy contains two dominant stellar populations of different age and
kinematics. The co-existence of multiple populations provides new constraints
on the dark halo structure of the galaxy, because different populations should
be in equilibrium in the same dark matter potential well. We develop
non-spherical dynamical models including such multiple stellar components and
attempt to constrain the properties of the non-spherical dark halo of Carina.
We find that Carina probably has a larger and denser dark halo than found in
previous works and a less cuspy inner dark matter density profile, even though
the uncertainties of dark halo parameters are still large due to small volume
of data sample. Using our fitting results, we evaluate astrophysical factors
for dark matter annihilation and decay and find that Carina should be one of
the most promising detectable targets among classical dSph galaxies. We also
calculate stellar velocity anisotropy profiles for both stellar populations and
find that they are both radially anisotropic in the inner regions, while in the
outer regions the older population becomes more tangentially biased than the
intermediate one. This is consistent with the anisotropy predicted from tidal
effects on the dynamical structure of a satellite galaxy and thereby can be
considered as kinematic evidence for the tidal evolution of Carina.
