Common Origin of Kinetic Scale Turbulence and the Electron Halo in the Solar Wind -- Connection to Nanoflares

TL;DR

This paper proposes that nanoflares in the solar corona generate electron beams that drive two-stream instability, leading to kinetic scale turbulence and the electron halo observed in the solar wind, supported by particle-in-cell simulations.

Contribution

It introduces a novel model linking nanoflare activity to the origin of solar wind turbulence and electron halo via electron two-stream instability, supported by simulation results.

Findings

Nanoflares and electron beams are common in the solar corona.

Electron two-stream instability can produce turbulence and electron halo features.

Energy exchange reaches equilibrium in the inner corona, preserving features during solar wind propagation.

Abstract

We summarize our recent studies on the origin of solar wind kinetic scale turbulence and electron halo in the electron velocity distribution function. Increasing observations of nanoflares and microscopic type III radio bursts strongly suggest that nanoflares and accelerated electron beams are common in the corona. Based on particle-in-cell simulations, we show that both the core-halo feature and kinetic scale turbulence observed in the solar wind can be produced by the nonlinear evolution of electron two-stream instability driven by nanoflare accelerated electron beams. The energy exchange between waves and particles reaches equilibrium in the inner corona and the key features of the turbulence and velocity distribution are preserved as the solar wind escapes into interplanetary space along open magnetic field lines. Observational tests of the model and future theoretical work are discussed.