Top: periodograms (left columns) of the GJ 3138 radial velocities. We subsequently subtract a model to fit data (raw RVs on top) until no clear signal remains on the residues (bottom). The k in the y-axis label depicts a Keplerian model (single or multiple), while the l represents the linear model between RVs and Hα (see text). In each step we modeled the signal highlighted with the horizontal dashed line. The right column represents the FAP derived from the bootstrap analysis. Each analyzed peak has a FAP under 0.75%. Bottom: window function exhibiting peaks located at 365 days, 240 days, 66 days, and 79 days.