CCFs between residuals of our best-fit full model and a ¹³CO template. The CCF shown in blue corresponds to the residuals between our KPIC data and our full model without taking ¹³CO into account. Conversely, the CCF in red corresponds to the residuals between our KPIC data and our full model while taking ¹³CO into account. The peak in the blue CCF (that is absent in the red CCF) at the exact RV shift measured for HD 984 B shown with a vertical gray line, confirms the presence of ¹³CO in our data.