Synchrotron Pair Production Equilibrium in Relativistic Magnetic Reconnection

Abstract

Magnetic reconnection is ubiquitous in astrophysical systems, and in many such systems, the plasma suffers from significant cooling due to synchrotron radiation. We study relativistic magnetic reconnection in the presence of strong synchrotron cooling, where the ambient magnetization $\sigma$ is high and the magnetic compactness ${\ell }_B$ of the system is of order unity. In this regime, $e^{\pm }$ pair production from synchrotron photons is inevitable, and this process can regulate the magnetization $\sigma$ surrounding the current sheet. We investigate this self-regulation analytically and find a self-consistent steady state for a given magnetic compactness of the system and initial magnetization. This result helps estimate the self-consistent upstream magnetization in systems where plasma density is poorly constrained, and can be useful for a variety of astrophysical systems. As illustrative examples, we apply it to study the properties of reconnecting current sheets near the supermassive black hole of M87, as well as the equatorial current sheet outside the light cylinder of the Crab pulsar.

11 pages, 2 figures, submitted to ApJ. Comments welcome!

References in corpus (10)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• Formation of Hard Power-laws in the Energetic Particle Spectra Resulting from Relativistic Magnetic Reconnection
• Sgr A* near-infrared flares from reconnection events in a magnetically arrested disc
• Particle acceleration in the driven relativistic reconnection
• Radiative reconnection-powered TeV flares from the black hole magnetosphere in M87
• Comptonization by Reconnection Plasmoids in Black Hole Coronae I: Magnetically Dominated Pair Plasma
• Pair Drizzle around Sub-Eddington Supermassive Black Holes
• Radiation GRMHD simulations of M87: funnel properties and prospects for gap acceleration
• Magnetic Reconnection in Black-Hole Magnetospheres: Lepton Loading into Jets, Superluminal Radio Blobs, and Multi-wavelength Flares
• Pair-Regulated Klein-Nishina Relativistic Magnetic Reconnection with Applications to Blazars and Accreting Black Holes

Cited by in corpus (7)

• Particle Injection and Nonthermal Particle Acceleration in Relativistic Magnetic Reconnection
• Relativistic Magnetic Reconnection in Astrophysical Plasmas: A Powerful Mechanism of Nonthermal Emission
• Observable signatures of stellar-mass black holes in active galactic nuclei
• High-energy synchrotron flares powered by strongly radiative relativistic magnetic reconnection: 2D and 3D PIC simulations
• Discovery of Limb Brightening in the Parsec-scale Jet of NGC 315 through Global Very Long Baseline Interferometry Observations and Its Implications for Jet Models
• Reconnection-driven Flares in M87*: Proton-Synchrotron-powered GeV Emission
• Nonuniform Particle Injection into Black Hole Jets by Radiative Magnetic Reconnection