Variation of the emission of the first and third quadrants (Q_I and Q_III in red dots) and the second and fourth quadrants (Q_II and Q_IV in blue dots)with the PA for our observation of AC Her (see Fig. C.1). The maximum emission of the mean of Q_I and Q_III indicates thePA, for which the rotational effect of the Keplerian dynamics along the nebula equator are best detected. The angle found is: PA = 136.1°. The subtraction of what we name Q_I + Q_III and Q_II + Q_IV shows the excess emission of the putative outflow along the nebula axis (black dots). We use thesame colors as in Fig. C.1. The magenta dotted lines represents PA = 46.1° and PA= 136.1°. These PA values represent the cut along the nebula axis and equator, respectively. The emission of the putative outflow is represented as a star at PA = 46.1° ± 1.4°. The error bar is the same for each point. The emission at the PA along the nebula axis is shown in the inset of the right corner.