Evolution of the Relativistic Plasmoid-Chain in the Poynting-Dominated Plasma

TL;DR

This study models the evolution of plasmoid chains in relativistic, Poynting-dominated plasmas, revealing how they accelerate magnetic reconnection and produce power-law distributions, with implications for high-energy astrophysics.

Contribution

It introduces a numerical model of relativistic plasmoid evolution in Poynting-dominated plasma and demonstrates key behaviors like secondary tearing instability and reconnection rate independence.

Findings

Plasmoid chains trigger secondary tearing instability.

Reconnection rate becomes independent of Lundquist number above a critical value.

Plasmoid size distribution follows a power law.

Abstract

In this paper, we investigate the evolution of the plasmoid-chain in a Poynting-dominated plasma. We model the relativistic current sheet with cold background plasma using the relativistic resistive magnetohydrodynamic approximation, and solve its temporal evolution numerically. We perform various calculations using different magnetization parameters of the background plasma and different Lundquist numbers. Numerical results show that the initially induced plasmoid triggers a secondary tearing instability, which gradually fills the current sheet with plasmoids, as has also been observed in the non-relativistic case. We find the plasmoid-chain greatly enhances the reconnection rate, which becomes independent of the Lundquist number, when this exceeds a critical value. In addition, we show the distribution of plasmoid size becomes a power law. Since magnetic reconnection is expected to play an important role in various high energy astrophysical phenomena, our results can be used for explaining the physical mechanism of them.