Generalised Lomb–Scargle periodograms of the radial velocities. The green and red vertical lines mark the period of planet b and c, respectively. The grey horizontal lines represent the 50, 10, and 1% p-value levels. From top to bottom: HIRES and SOPHIE data; HIRES velocities; SOPHIE velocities; SOPHIE after substraction of Keplerian curve at the period of planet b; SOPHIE velocities after substraction of a two-Keplerian model with the periods of planets b and c. The periodogram plots are provided by DACE (dace.unige.ch).