Detailed comparison of the helium and metal lines of the observed spectrum (black) with the global best-fitting solution (red) at different times. The spectra are shifted into the rest frame of the primary star (HD 37061 Aa). The plots in the first column have a different scaled flux axis. Top row: comparison with the spectrum used for the analysis, observed on March 8, 2007. Bottom row: comparison with a spectrum observed on January 12, 2006. The only difference between the models in the top and bottom row is the radial velocity shift of each stellar component.