Cherenkov-Curvature Radiation and Pulsar Radio Emission Generation
نویسندگان
چکیده
Electromagnetic processes associated with a charged particle moving in a strong circular magnetic field are considered in cylindrical coordinates. We investigate the relation between the vacuum curvature emission and Cherenkov emission and argue that, for the superluminal motion of a particle in the inhomogeneous magnetic field in a dielectric, the combined effects of magnetic field inhomogeneity and the presence of a medium give rise to the synergetic Cherenkov-curvature emission process. We find the conditions when the operator relations between electric field and electric displacement in cylindrical coordinates may be approximated by algebraic relations. For nonresonant electromagnetic wave, the interaction with particles streaming along the curved magnetic field may be described in the WKB approximation. For resonant waves, interacting with superluminal particles we use a plane wave approximation to compute the local dielectric tensor of a plasma in a weakly inhomogeneous magnetic field. We find in this approximation the polarization of normal modes in the plasma, Cherenkov-curvature and Cherenkov-drift emissivities and growth rates.
منابع مشابه
Coherent Mechanisms of Pulsar Radio Emission
Relativistic plasma masers operating on the anomalous cyclotronCherenkov resonance ω − k‖v‖ + ωB/ γres = 0 and the Cherenkov-drift resonance ω − k‖v‖ − kxud = 0, are capable of explaining the main observational characteristics of pulsar radio emission. Both electromagnetic instabilities are due to the interaction of the fast particles from the primary beam and from the tail of the secondary pai...
متن کاملOn the Nature of Pulsar Radio Emission
A theory of pulsar radio emission generation, in which the observed waves are produced directly by maser-type plasma instabilities operating at the anomalous cyclotron-Cherenkov resonance ω − k‖v‖ + ωB/ γres = 0 and the Cherenkov-drift resonance ω − k‖v‖ − k⊥ud = 0, is capable of explaining the main observational characteristics of pulsar radio emission. The instabilities are due to the interac...
متن کاملExcitation of Alfvén Waves and Pulsar Radio Emission
We analyze mechanisms of the excitation of Alfvén wave in pulsar magnetospheres as a possible source of pulsar radio emission generation. We find that Cherenkov excitation of obliquely propagating Alfvén waves is inefficient, while excitation at the anomalous cyclotron resonance by the particles from the primary beam and from the tail of the bulk distribution function may have a considerable gr...
متن کاملCurvature radiation in pulsar magnetospheric plasma
We consider the curvature radiation of the point-like charge moving relativistically along curved magnetic field lines through a pulsar magnetospheric electron-positron plasma. We demonstrate that the radiation power is largely suppressed as compared with the vacuum case, but still at a considerable level, high enough to explain the observed pulsar luminosities. The emitted radiation is polariz...
متن کاملUnraveling the nature of coherent pulsar radio emission
Forty years have passed since the discovery of pulsars, yet the physical mechanism of their coherent radio emission is a mystery. Recent observational and theoretical studies strongly suggest that the radiation outcoming from the pulsar magnetosphere consists mainly of extraordinary waves polarized perpendicular to the planes of pulsar dipolar magnetic field. However, the fundamental question w...
متن کامل