From top to bottom, row 1: median residuals of the radial velocity as a function of surface gravity for samples of metal-rich giants. Row 2: median residuals of the radial velocity as a function of effective temperature for samples of metal-rich main sequence stars. Rows 3 and 4: median residuals of the radial velocity as a function of metallicity for samples of giants and main-sequence stars, respectively. The metallicity trends are presented relative to solar metallicity (see text). The 68.3% confidence interval on the measurements of the medians is represented as shaded areas.