Top row: time series of the Hα activity index. The green points correspond to ELODIE observations, and red empty symbols and red filled symbols are for SOPHIE and SOPHIE+, respectively. The same scale is used for all stars to ease comparison. Bottom row: generalised Lomb-Scargle periodogram for the SOPHIE and SOPHIE+ Hα index. It was assumed that no offset exists between the index measurement of SOPHIE and SOPHIE+. The red vertical dotted lines signal the position of the highest peaks whose periods are annotated, the blue shaded areas represent the 2σ intervals for the stellar rotational periods listed in Table 2, and the green vertical dashed lines corresponds to the maximum a posteriori orbital period of the orbiting companions.