Schematic representation of the binary system merger. A coordinate system (x,y,z) is shown, where the line of sight coincides with the z-axis. The primed coordinate system is achieved through a rotation by angle ψ in the x-y plane and with an angle ι around the x-axis. Through this the jet with angular momentum vector L, is aligned with the z’-axis. The jet plane, from which the gamma rays are emitted, is indicated in purple while the half jet opening angle θ_c is shown as well. In the current figure the gamma-ray emission would not be observed, as the jet plane points away from the observer.