a)TD/D distribution of our sample of 714 stars. The solid vertical lines mark the TD/D = 0.5 and TD/D = 2 ratios. Panels b)–d): metallicity distributions of 239 potential thick disk stars with TD/D > 2, out of which 36 stars have TD/H < 1, i.e. most likely halo stars; 88 stars with kinematics “in between”; and the 387 potential thin disk stars with TD/D < 0.5. In a) and b) the likely halo stars (TD/H < 1) are marked by solid black histograms. The metallicities are from our spectroscopic analysis.