Evolution of the pulse width (w₁,w₂) with respect to the precession phase ϕ. The two fitting models are shown, Gaussian in red and Lorentzian in blue. For the first plot (panel a)) significant emission occurs only in the phase interval φ ∈ [0.2,0.8]. This is because the line of sight does not intersect the high-energy beam anymore. The plot outside this range is therefore irrelevant.