(a) Generalized Lomb-Scargle periodograms of GJ 686 radial velocity data. The top panel shows the WF of the combined dataset. The next four panels represent the HIRES, HARPS, HARPS-N, and CARMENES data, respectively, and the bottom panel shows the periodogram of the combined dataset. The periods reported in each panel refer to the highest peak. Horizontal lines represent the bootstrapped FAP levels of 10, 1, and 0.1%. The vertical solid and dashed red lines indicate the period of the proposed planet and estimated stellar rotation period at 15.53 and ~38 d, respectively.(b) Generalized Lomb-Scargle periodograms of the RV residuals after removing a sinusoid with the period found in (a).