Left panels: stellar mass profile as a function of longitude for three different latitudes for MP (blue) and MR (red) stars, respectively. Right panels: same thing for the galactocentric radial velocity profile. At b = ±1 the curves are dashed, except at l = 0, to point out that they are constrained by a single field at (l, b) ∼ (0, −1), and, only through the interpolation, by the fields at (b = −2).