RVs of both components in 2dFS 2553 as a function of phase. Upper panel: Observed (triangles) and synthetic (solid lines) RV curves of the primary (green) and secondary (red) as obtained with the PHOEBE code. The dashed black line indicates the systemic velocity v_γ. Middle panel: Residuals of the primary’s RVs after subtraction of the model. Lower panel: Residuals of the secondary’s RVs after subtraction of the model.