Halo masses and concentrations of the primordial Galactic halos derived from the Gaia circular velocity fits using 12 baryonic models. The red and blue stars with errors represent the halos with and without adiabatic contraction, respectively. The predicted halo mass-concentration relation within 1σ from simulations (Dutton & Macciò 2014) is shown as the declining band. The vertical band shows the expected range of the MW halo mass according to the abundance-matching relation (Moster et al. 2013). The upper and lower limits are set by the highest stellar mass (model A&S) plus 1σ and the lowest stellar mass (model I) minus 1σ, respectively.