Self-discharge by streaming cosmic rays

TL;DR

This paper proposes a new nonthermal phenomenon called self-discharge caused by streaming cosmic rays, which accelerates secondary electrons and impacts ionization, emission, and magnetic field processes in the universe.

Contribution

It introduces the concept of self-discharge by streaming cosmic rays, detailing the conditions for its occurrence and its effects on secondary electron acceleration and magnetic field dynamics.

Findings

Resistive electric fields can accelerate secondary electrons.

Self-discharge enhances ionization and nonthermal emissions.

It influences magnetic field generation and amplification.

Abstract

A new nonthermal phenomenon caused by streaming cosmic rays (CRs) in the universe is proposed. The streaming CRs drive the return current of thermal electrons to compensate for the CR current. Then, electric fields are induced by the resistivity of the return current. It is shown that the resistive electric fields can accelerate secondary electrons generated by the streaming CRs. This is the self-discharge by streaming CRs. In this work, the self-discharge condition and the condition for runaway acceleration of secondary electrons are presented. The self-discharge makes high-energy secondary electrons, resulting in enhancements of ionization and nonthermal emission including K$\alpha$ emission line of neutral irons. After the self-discharge, the return current of thermal electrons is replaced by the electric current of secondary electrons. Since some magnetic field generations and amplifications are driven by the return current of thermal electrons, the self-discharge can significantly influence them.