Determination of the best SYSREM iteration. Shown is the progression of the S/N of the recovered signal with the number of SYSREM iterations for the injected signal (blue solid line), the blueshifted signal (orange dashed line), and the redshifted signal (green dotted line). Panels a, b and c show the values for SYSREM performed in (quasi-)stellar rest frame, leading to the results shown in Fig. 2. Panels d, e and f show the values for SYSREM performed in telluric rest frame leading to the results shown in Fig. A.2. In all cases the diamonds indicate the peak signal position.