S/N maps of Fe obtained by using a non-inverted T–p profile for cross-correlation (Nugroho et al. 2017). Panel a: anticorrelation signal of Fe in the CARMENES data (S/N = −4.3); panel b: anticorrelation with the HARPS-N data (S/N = −4.6). The coordinates of the negative S/N peaks are indicated by the yellow dashed lines. The cross-sections of the negative S/N peaks are reported in the horizontal and vertical panels. Each S/N map corresponds to the SYSREM iteration number that maximizes the detection strength in Sects. 5.1 and 5.2.