Dynamical feedback of the curvature drift instability on its saturation process

Abstract

Aims. We investigate the reconstruction of pulsar magnetospheres close to the light cylinder surface to study the curvature drift instability (CDI) responsible for the twisting of magnetic field lines in the mentioned zone. The influence of plasma dynamics on the saturation process of the CDI is studied. Methods. On the basis of the Euler, continuity, and induction equations, we derive the increment of the CDI and analyze parametrically excited drift modes. The dynamics of the reconstruction of the pulsar magnetosphere is studied analytically. Results. We show that there is a possibility of a parametrically excited rotational-energy pumping-process in the drift modes. It is indicated by the generation of a toroidal component of the magnetic field that transforms the field lines into such a configuration, in which plasma particles do not experience any forces. At this stage, the instability process saturates and the further amplification of the toroidal component to the magnetic field lines is suspended.

On the Very High Energy Spectrum of the Crab Pulsar

“…This particular problem was considered in Machabeli & Osmanov (2010), in which analyzing inverse Compton scattering, demonstrated that, for reasonable physical parameters, even very energetic electrons are unable to produce the photon energies of the order of 25 GeV. Studying curvature radiation, we found that the curvature drift instability (CDI; Osmanov et al 2008Osmanov et al , 2009) efficiently rectifies the magnetic field lines, making the role of the curvature emission process negligible (Machabeli & Osmanov 2010).…”

Millisecond newly born pulsars as efficient accelerators of electrons

“…How about the curvature radiation emitted by particles moving along the curved magnetic field lines? To explain force free regime of particles leaving a pulsar’s magnetosphere, we have tried to reconstruct the structure of magnetic field close to the light cylinder surface 17 . We showed that shown that the curvature driven current imparts a toroidal component to the magnetic field.…”

On the mechanism of the pulsed high-energy emission from the pulsar PSR B1509-58

“…This automatically means that the curvature radii of the magnetic field lines are large enough to ensure the negligible role of the curvature radiation process. As shown by Osmanov, Dalakishvili & Machabeli (2008) and Osmanov, Shapakidze & Machabeli (2009), such a configuration of field lines might be provided by the so‐called curvature drift instability, which makes the magnetic field lines rectify efficiently in the very vicinity of the light‐cylinder surface. In particular, as shown in the aforementioned papers, the curvature drift (see ) creates the corresponding current, leading to the creation of an additional magnetic field.…”