Generation of Crab Nebulae Wisps by Plasma Drift Instability

O. Chedia, J. Lominadze, G. Machabeli, G. Mchedlishvili, D. Shapakidze
1997 Astrophysical Journal  
A new mechanism of wisp formation in the Crab Nebula, without recourse to a shock wave, is presented. The mechanism is based on the plasma processes taking place in the relativistic electron-positron plasma, in particular, on excitation of the drift instability in the slightly inhomogeneous magnetic Ðeld of the nebula. The magnetic Ðeld geometry is assumed to be untwisting spiralÈlike, concentrated around the rotational equatorial plane of the pulsar. We infer that the energy is transported
more » ... the pulsar to the nebula not only by the Poynting Ñux but also by the kinetic energy of the particles moving along the Ðeld lines. We consider a speciÐc relativistic electron-positron plasma with Lorentz factor pen-c B D 10 etrated by an ion beam with It is shown that in such a plasma, taking into account the drift, c b D 106. the generation of low-frequency waves propagating transversely to the magnetic Ðeld is possible. In this way the excited Ðeld causes additional alteration of the magnetic Ðeld geometry. The higher lumi-B r nosity of certain spots is explained by the reorientation of the direction of motion of the synchrotron radiation source (Larmor circle) relative to the observer. The sizes, variability of luminosity, spatial asymmetry, polarization, and transfer velocity, i.e., the main properties of the wisps, are explained. Some predictions are also made.
doi:10.1086/303855 fatcat:x6l4udt4xndj3kn3h2zbxyvcfi