Illustration of the global line profile (i.e. combining the disk and shell contributions and accounting for the full array of transitions), adopting the default parameters of γ Cas at four different orbital phases. The blue histogram shows the spectrum binned in energy bins of 1 eV, whereas the black line provides the result of the convolution with an instrumental response of 6 eV. The magenta lines indicate the position of the centroids of the Kα₁ and Kα₂ subgroups at phase ϕ = 0.0.