Self-discharge by streaming cosmic rays

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.

6 pages, 1 figure, accepted for publication in ApJ

References in corpus (10)

• Detection of the Characteristic Pion-Decay Signature in Supernova Remnants
• Cosmic ray feedback in hydrodynamical simulations of galaxy formation
• Production of Magnetic Turbulence by Cosmic Rays Drifting Upstream of Supernova Remnant Shocks
• The transport of cosmic rays in self-excited magnetic turbulence
• Nonthermal X-rays from low-energy cosmic rays: Application to the 6.4 keV line emission from the Arches cluster region
• Rigorous theory for secondary cosmic-ray ionization
• The Biermann battery driven by a streaming plasma
• Fast Particle Acceleration at Perpendicular Shocks with Uniform Upstream Magnetic Field and Strong Downstream Turbulence
• Magnetic field generation by an inhomogeneous return current
• The Origin of Ripples in Cool Cores of Galaxy Clusters: Heating by MHD Waves?