Centrifugally induced curvature drift instability in AGN

TL;DR

This paper analyzes how centrifugal forces induce curvature drift instability near the light cylinder of AGN, showing it occurs rapidly and could significantly impact plasma dynamics.

Contribution

It provides an analytical study of the curvature drift instability in AGN, revealing its efficiency and potential influence on AGN plasma processes.

Findings

Instability timescale is much shorter than accretion timescale.

The instability is highly efficient in AGN plasma environments.

Field lines twist near the light cylinder due to centrifugal effects.

Abstract

We investigate the centrifugally driven curvature drift instability to study how field lines twist close to the light cylinder surface of an AGN, through which the free motion of AGN winds can be monitored. By studying the dynamics of the relativistic MHD flow close to the light cylinder surface, we derive and solve analytically the dispersion relation of the instability by applying a single particle approach based on the centrifugal acceleration. Considering the typical values of AGN winds, it is shown that the timescale of the curvature drift instability is far less than the accretion process timescale, indicating that the present instability is very efficient and might strongly influence processes in AGN plasmas.