The distribution function of the Galaxy's dark halo
  Starting from the hypothesis that the Galaxy's dark halo responded
adiabatically to the infall of baryons, we have constructed a self-consistent
dynamical model of the Galaxy that satisfies a large number of observations,
including measurements of gas terminal velocities and masers, the kinematics of
a 180,000 giant stars from the RAVE survey, and star count data from the SDSS.
The stellar disc and the dark halo are both specified by distribution functions
(DFs) of the action integrals. The model is obtained by extending the work of
Piffl Penoyre & Binney (2015} from the construction of a single model to a
systematic search of model space. Whereas the model of Piffl et al violated
constraints on the terminal-velocity curve, our model respects these
constraints by adopting a long scale length R_d=3.66 kpc for the thin and thick
discs. The model is, however, inconsistent with the measured optical depth for
microlensing of bulge stars because it attributes too large a fraction of the
density at R <~ 3 kpc to dark matter rather than stars. Moreover, it now seems
likely that the thick disc's scale-length is significantly shorter than the
model implies. Shortening this scale-length would cause the constraints from
the rotation curve to be violated anew. We conclude that we can now rule out
adiabatic compression of our Galaxy's dark halo.
