Correlations of the HARPS-N (top) and CARMENES (bottom) chromospheric line indices with the RV data. The red ellipses show the theoretical phase-shifted correlation using the phase shifts of periodicities of 19.11 d (HARPS-N) and 18.92 d (CARMENES), respectively, and the rms of the data as the amplitude of the signal. The blue lines represent the best linear fit, i.e., the Spearman factor. At the top of each image, we show the Spearman (SP) and Pearson (PE) factors together with their respective p-values in parenthesis.