Radial velocity residuals of the MAP-estimate k0d0rn model (top panel), and generalised Lomb Scargle periodograms under the red noise models. The horizontal lines in the periodogram panels correspond to p-value levels of 0.5, 0.1, 0.01, and 1 × 10⁻³, from bottom to top, and are computed for each dataset by bootstrapping (see text for details). Second from top panel: GLS of radial velocities after zero-point correction and removal of secular acceleration term, that is the residuals of the k0d0model shown in the top panel; third from top panel: residuals of k0d1 model, containing an additional constant acceleration; second from bottom panel: residuals of the k1d0 model, with a Keplerian curve of period P = 12.9438 days; bottom panel: as above, but including also a linear acceleration term in the model (model k1d1). A version of the periodograms using a linear frequency scale in the x-axis is provided in Appendix A (Fig. A.1).