Energy-resolved beam patterns after cyclotron scattering for a cylindrical geometry (“fan beam”). Left: case of a static plasma. Right: plasma with bulk velocity v = 0.4c. The black line shows the angular distribution of all photons. The red, green, and blue lines mark photons escaping at energies close to the cyclotron resonances for the respective angles (not to scale). While the photons that escape at the fundamental resonance (red) have all undergone scattering, the photons escaping at the higher resonances are unaltered from the continuum (see Schwarm et al. 2013).