A Free-Electron Laser in the Pulsar Magnetosphere

Abstract

We have studied systematically the free-electron laser in the context of high brightness pulsar radio emission. In this paper, we have numerically examined the case where a transverse electromagnetic wave is distorting the motion of a relativistic electron beam while travelling over one stellar radius ($approx10:km$). For different sets of parameters, coherent emission is generated by bunches of beam electrons in the radio domain, with bandwidths of 3 GHz. Pulse power often reached $10^{13}:W$, which corresponds with brightness temperature of $10^{30}:K$. The duration of these pulses is of the order of nanoseconds. In the context of pulsar radio emission, our results indicate that the laser can produce elementary bursts of radiation which build up the observed microstructures of a few tens of microseconds duration. The process is sensitive mostly to the beam particles energy, number density and the background magnetic field, but much less so to the transverse wave parameters. We demonstrate that the operation of a free-electron laser with a transverse electromagnetic wiggler in the pulsar magnetosphere occurs preferably at moder ate Lorentz factors $gammageq100$, high beam density $ngtrsim0.1n_{textrmGJ}(r_{a}st)$ where $n_{textrmGJ}(r_{a}st)$ is the Goldrei ch-Julian density at a stellar radius $r_{a}st$, and finally, at large altitude where the background magnetic field is low $B_{0}leq10^{-2}textrmT$.

arXiv comment11 pages, 25 figures, Accepted for publication in A&A

References in corpus (2)

• The spark-associated soliton model for pulsar radio emission
• Pulsar microstructure and its quasi-periodicities with the S2 VLBI system at a resolution of 62.5 nanoseconds

Cited by in corpus (17)

• The Physics of Fast Radio Bursts
• Coherent Emission Mechanisms in Astrophysical Plasmas
• Magnetospheric Eclipses in the Binary Pulsar J0737-3039
• Coherent inverse Compton scattering by bunches in fast radio bursts
• Radio Emission Physics in the Crab Pulsar
• Pulsar radio emission mechanisms: a critique
• On the origin of the drifting subpulses in radio pulsars
• Is the Bursting Radio-source GCRT J1745-3009 a Double Neutron Star Binary ?
• A Pulsational Model for the Orthogonal Polarization Modes in Radio Pulsars
• Radio Emission by Soliton Formation in Relativistically Hot Streaming Pulsar Pair Plasmas
• Radio Emission of Pulsars. II. Coherence Catalyzed by Cerenkov-Unstable Shear Alfvén Waves
• Particle-in-cell simulations of electron-positron cyclotron maser forming pulsar radio zebras
• The Moving Mirror model for Fast Radio Bursts
• On the Unpulsed Radio Emission from J0737-3039
• Origin of radio polarization in pulsar polar caps
• Bunch Expansion as a cause for Pulsar Radio Emissions
• Whistler Chorus Amplification in the Magnetosphere: The Nonlinear Free-Electron Laser Model and the Ginzburg-Landau Equation