Top: periodogram of the RV time series of HD 87816. Middle: periodogram obtained after fitting a first Keplerian model with a period of 480 days. Bottom: Periodogram of the residuals of the RV time series after subtraction of the two-planet model. The horizontal lines show the different FAP levels: 1% (dashed orange line) and 0.1% (dashed-dotted blue line). The highest peak is marked with a red dot, and the corresponding period is indicated next to it.