Top: radial velocity of LHS 1140 from the HARPS (red) and ESPRESSO (open for ESPRESSOpre and filled for ESPRESSOpost in green) datasets. The black line shows the median radial velocity model from the joint photometric and radial velocity analysis including the two known Keplerian signals and the GP model (see Sect. 6). The gray shaded regions correspond to the 68.7% (dark gray) and 95% (light gray) confidence intervals of the model. The median GP model is shown as a dashed blue line. Middle: radial velocity dataset after removing the median GP model. The Keplerian model is shown as a solid black line. Bottom: radial velocity residuals of the full model.