On the collective curvature radiation

Abstract

The paper deals with the one possible mechanism of the pulsar radio emission, i.e., with the collective curvature radiation of the relativistic particle stream moving along the curved magnetospheric magnetic field lines. It is shown that the electromagnetic wave containing one cylindrical harmonic exp{is{\phi}} can not be radiated by the curvature radiation mechanism, that corresponds to radiation of a charged particle moving along curved magnetic field lines. The point is that the particle in vacuum radiates the triplex of harmonics (s, s \pm 1), so for the collective curvature radiation the wave polarization is very important and cannot be fixed a priori. For this reason the polarization of real unstable waves must be determined directly from the solution of wave equations for the media. Its electromagnetic properties should be described by the dielectric permittivity tensor \^{\epsilon}({\omega},k,r), that contains the information on the reaction on all possible types of radiation.Comment: 7 pages, 1 figure, submitted to MNRA

Radio pulsars: the search for truth

“…Thus, as we have shown (also see Ref. [96]), a wave with a polarization [E ρ (ρ); E ϕ (ρ)] exp{isϕ}, containing a single azimuthal harmonic s, satisfies only the Cherenkov radiation mechanism, while the emission of a charged particle in a circular magnetic field in the vacuum involves three azimuthal harmonics, s and s ± 1. This property provides an exit for the wave from the phase synchronism of the particle currrent.…”

“…Here, ρ c = c/ω c is the cyclotron radius and ρ 0 is the curvature radius. But as we now show, this approach cannot be used in analyzing the collective curvature radiation either (in more detail see [96]).…”

Pulsar emission: Langmuir modes in a relativistic multicomponent plasma

“…The hypothesis appears reasonable, but given the complexity, we are unable to offer any proof. It is distinct from other work which has considered specific mechanisms in detail, for example, maser emission due to curvature drift (Luo & Melrose 1992) or collective curvature radiation (Kaganovitch & Lyubarsky 2010;Istomin, Philippov & Beskin 2012). The ion-proton plasma Lorentz factors considered here are only moderately large and would give coherent curvature radiation only at frequencies of the order of 1 MHz.…”

Extinct radio pulsars as a source of subrelativistic positrons

“…Relativistic particles, moving with acceleration across the magnetic field due to curvature of magnetic field lines, generate electromagnetic waves. This radiation, named curvature radiation, can reach high powers due to the collective generation effect (Istomin et al 2012). For radio pulsars, the efficiency of generating radio waves in the magnetosphere, the ratio of the energy flux of radio emission to the energy flux of relativistic particles, is αr ≃ 10 −6 (Beskin et al 1993).…”