Lattice of Langmuir solitons in the pulsar magnetosphere

Abstract

From the study of the nonlinear evolution of the relativistic two-stream instability in the physical conditions of the pulsar magnetosphere, that gives rise to strong Langmuir turbulence, we conclude to the probable existence of a lattice of stable Langmuir soliton-like solutions, called "Langmuir microstructures". Such microstructures are associated to three different types of radiation mechanisms. The first mechanism is direct radiation of the microstructures. The second one is curvature radiation of the microstructures moving along the dipolar pulsar magnetic field lines. The third one is related to the acceleration of beam particles in interaction with the lattice of Langmuir microstructures. It can be extremely efficient when some coherence is maintained between the phases of beam particles, for instance by a modulation of the beam. The conditions in which one or the other of these three radiation mechanisms can account for observed pulsar radio luminosities are given.