SIMBAD references

Interpretation of the non-thermal optical emission of pulsars as a spontaneous synchrotron re-emission of the secondary particles involved in the process of resonant absorption of pulsar radio emission is suggested. In the outer magnetosphere, where the condition of cyclotron resonance is fulfilled, the radio waves are subject to resonant absorption. Although this process is not efficient enough to suppress the integrated radio luminosities dramatically, it causes substantial evolution of the momenta of absorbing particles. The particle pitch angles become ~θ (where θ is the angle of incidence of resonant photons) and the total momenta can change within a few orders of magnitude. The synchrotron radiation of these particles falls into the optical and higher energy range. Because of strong spatial evolution of the particle momenta, the critical frequency of synchrotron radiation varies markedly inside the emitting volume. Therefore the resultant spectra are very flat over a wide frequency range. Our model is applicable for both middle-aged and young pulsars, providing the optical luminosities ∼10²⁸ erg.s^–1 and up to ∼10³⁴ erg.s^–1, respectively. In the case of the Crab pulsar, one can explain the high-energy spectrum up to ∼10 MeV.