A new mechanism for dissipation of alternating fields in Poynting dominated outflows

TL;DR

This paper introduces a novel self-sustaining magnetic reconnection mechanism driven by Kruskal-Schwarzschild instability in Poynting dominated outflows, which is especially effective in AGN and GRB environments.

Contribution

It identifies the Kruskal-Schwarzschild instability as a key facilitator of magnetic reconnection in accelerating flows, providing a new dissipation mechanism in astrophysical outflows.

Findings

The instability develops in accelerated flows, enabling rapid reconnection.

The mechanism is less effective in pulsar winds compared to other dissipation processes.

It is highly efficient in AGN and GRB conditions.

Abstract

Reconnection of alternating magnetic fields is an important energy transformation mechanism in Poynting dominated outflows. We show that the reconnection is facilitated by the Kruskal-Schwarzschild instability of current sheets separating the oppositely directed fields. This instability, which is a magnetic counterpart of the Rayleigh-Taylor instability, develops if the flow is accelerated. Then the plasma drips out of the current sheet providing conditions for rapid reconnection. Since the magnetic dissipation leads to the flow acceleration, the process is self-sustaining. In pulsar winds, this process could barely compete with the earlier proposed dissipation mechanisms. However, the novel mechanism turns out to be very efficient at AGN and GRB conditions.