Densities of stars in the V_ϕ – [Fe/H] space. The grid corresponds to areas delimited in V_ϕ and [Fe/H]. The scaling of contaminants varies from one area to another with the density of PGS in each area. The dimension of a pixel is 0.1 dex × 10 km.s⁻¹. First panel (top): PGS only. In the next rows of panels: left = APOGEE, right = LAMOST. Second row: density of spectroscopic contaminants, scaled to the sample size of PGS in each pixel. Third row: PGS decontaminated pixel-by-pixel, i.e. subtraction between a pixel of PGS density and a pixel of spectroscopic contamination density. Fourth row: residuals percentages of the pixel-by-pixel decontamination of PGS. Fifth row: PGS decontaminated by the mean of the spectroscopic contamination, i.e. by the mean of the spectroscopic contamination density in a designated V_ϕ – [Fe/H] area.