Low-metallicity stellar halo populations as tracers of dark matter
  haloes
  We analyse the density profiles of the stellar halo populations in eight
Milky-Way mass galaxies, simulated within the $\Lambda$-Cold Dark Matter
scenario. We find that accreted stars can be well-fitted by an Einasto profile,
as well as any subsample defined according to metallicity. We detect a clear
correlation between the Einasto fitting parameters of the low-metallicity
stellar populations and those of the dark matter haloes. The correlations for
stars with [Fe/H]$<-3$ allow us to predict the shape of the dark matter
profiles within residuals of $\sim 10 $ per cent, in case the contribution from
in situ stars remains small. Using Einasto parameters estimated for the stellar
halo of the Milky Way and assuming the later formed with significant
contributions from accreted low-mass satellite, our simulations predict $\alpha
\sim 0.15 $ and $r_2 \sim 15$ kpc for its dark matter profile. These values,
combined with observed estimations of the local dark matter density, yield an
enclosed dark matter mass at $\sim 8$ kpc in the range $3.9 - 6.7 \times
10^{10}$ M$_{\odot}$, in agreement with recent observational results. These
findings suggest that low-metallicity stellar haloes could store relevant
information on the DM haloes. Forthcoming observations would help us to further
constrain our models and predictions.
