The<i>Gaia</i>-ESO Survey: the Galactic thick to thin disc transition

Aims. The nature of the thick disc and its relation to the thin disc is presently an important subject of debate. In fact, the structural and chemodynamical transition between disc populations can be used as a test of the proposed models of Galactic disc formation and evolution. Methods. We used the atmospheric parameters, [/Fe] abundances, and radial velocities, which were determined from the Gaia-ESO Survey GIRAFFE spectra of FGK-type stars (first nine months of observations) to provide a chemo-kinematical characterisation of the disc stellar populations. We focussed on a subsample of 1016 stars with high-quality parameters, covering the volume |Z| < 4.5 kpc and R in the range 2-13 kpc.