GLS periodograms for the combined CARMENES data set of maps 6 and 7 for each of the considered indicators. The dotted red line marks the rotation period (P_rot = 4.34 d, or frequency = 0.228 d⁻¹) and the dotted blue line indicates the second harmonic at P_rot/2. The horizontal lines indicate the statistical significance of the detected periodicities shown as the 10% (dotted), 1% (dashed), and 0.1% (dash-dotted) false-alarm probability levels. The number of used CARMENES spectra is indicated by N after a 2σ clipping.