Power-Law Injection Spectrum from an Ensemble of Reconnecting Current Sheets
Abstract
A collisionless, low-β plasma undergoing strong sub-Alfvénic turbulence is expected to form a broad hierarchy of reconnecting current sheets immersed in a strong guide magnetic field. If the reconnecting field strength of a sheet scales with its length as a power law of index κ, and the number of sheets per unit interval of sheet length decreases as a power law of index x, the current-sheet ensemble injects nonthermal particles with a power-law energy spectrum ∝ γ−s, where s = 1 + (x−2)/(1 + κ). The spectrum is hard (s < 2) when the longest sheets deliver most of the injected energy, which requires x < 3 + κ. Past numerical studies have measured 2 ≲ x ≲ 3.3, and the scalings of intense current sheets support κ≳ 0, resulting in 1 ≲ s ≲ 2.3. This injection may yield flat or mildly steep radio spectra in optically thin sources and hard ion spectra in the coronae of active galactic nuclei.
Related
- Dynamical and thermal evolution of localized reconnecting current sheets under varying guide fields in the solar corona
- Dynamical and thermal evolution of localized reconnecting current sheets under varying guide-fields in the solar corona
- Current Sheets and Magnetic Reconnection statistics by Solar Orbiter at few to tens of Ion Inertial Lengths II: Conditions for Reconnection, and Current Sheet Planarity
- Ion-scale current sheets embedded in the reconnection-jet shear layer of the near-Sun heliospheric current sheet
- Bifurcations in the Heliosphere: Global-scale Coronal Pseudostreamer Evolution and the Creation of Secondary Heliospheric Current Sheets
BibTeX
@misc{french2026powerlaw,
title = {{Power-Law Injection Spectrum from an Ensemble of Reconnecting Current Sheets}},
author = {Omar French},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.07160},
eprint = {2610.07160},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.07160},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Power-Law Injection Spectrum from an Ensemble of Reconnecting Current Sheets
AU - Omar French
PY - 2026
DA - 2026/10/05
PB - arXiv
DO - 10.48550/arxiv.2610.07160
UR - https://arxiv.org/abs/2610.07160
AB - A collisionless, low-β plasma undergoing strong sub-Alfvénic turbulence is expected to form a broad hierarchy of reconnecting current sheets immersed in a strong guide magnetic field. If the reconnecting field strength of a sheet scales with its length as a power law of index κ, and the number of sheets per unit interval of sheet length decreases as a power law of index x, the current-sheet ensemble injects nonthermal particles with a power-law energy spectrum ∝ γ^−s, where s = 1 + (x−2)/(1 + κ). The spectrum is hard (s < 2) when the longest sheets deliver most of the injected energy, which requires x < 3 + κ. Past numerical studies have measured 2 ≲ x ≲ 3.3, and the scalings of intense current sheets support κ≳ 0, resulting in 1 ≲ s ≲ 2.3. This injection may yield flat or mildly steep radio spectra in optically thin sources and hard ion spectra in the coronae of active galactic nuclei.
ER -