Schematic representation of the outflow geometry parametrization described in Sect. 5.4. The figure illustrates the front (left) and side (right) view of an outflow characterized by an arbitrary OA, PA = 90° and RA = 45°. The opening angle represents the angle between the axis and the surface of each outflow cone, the position angle corresponds to the angle of the outflow with respect to the horizontal axis, in the plane of the sky, and the rotation angle measures the rotation of the outflow in the plane defined by x = 0, with respect to the y-axis. The red line shows the cone axis. The observer is located at a large positive z value.