Excitation of Langmuir Waves in the Magnetospheres of AGN

Abstract

In the paper we study the process of excitation of Langmuir waves in the magnetospheres of active galactic nuclei (AGN), by taking a general-relativistic expression of the GoldreichJulian density into account. We considered the linearised set of equations which describe dynamics of the studied mechanism: the Euler equation, the continuity equation and the Poisson equation. After solving the dispersion relation and obtaining the instability growth rate, we explored it versus several physical parameters: electron’s and proton’s relativistic factors and the mass and luminosity of AGN, which are supposed to be Kerr black holes. We showed that the parametric process of energy pumping into the Langmuir waves is very efficient and the electrostatic field’s amplitude will be exponentially amplifying, which might account for pair creation, particle acceleration and plasma heating processes in the nearby regions of AGN.

Magnetocentrifugal Mechanism of Pair Creation in AGN

“…The generation of electrostatic waves is fully governed by the set of following equations (rewritten in Fourier space) [28]…”

“…Following the method originally developed for AGN in [23] (see also the detailed study in [28]) one obtains the dispersion relation of the process…”

“…one can estimate the scale of the shell ∆r γ 0 R lc /(2γ) [28]. Here, γ 0 is the initial relativistic factor and R lc = c/Ω 0 represents the LC radius.…”

“…In [28], the excitation of magnetocentrifugally driven Langmuir waves was explored by taking the general expression of GJ density into account. The increment of the process has been studied for a wide range of physical parameters, including the particle Lorentz factors, AGN luminosity, and the mass of the central object.…”