Work

Magnitude of Short-wavelength Electric Field Fluctuations in Simulations of Collisionless Plasma Shocks

Year: 2025

Type: article

Abstract: Large-amplitude electrostatic fluctuations are routinely observed by spacecraft upon traversal of collisionless shocks in the heliosphere. Kinetic simulations of shocks have struggled to reproduce the amplitude of such fluctuations, complicating efforts to understand their influence on energy dissipation and shock structure. In this paper, one-dimensional particle-in-cell simulations with realistic proton-to-electron mass ratio are used to show that in cases with upstream electron temperature T e exceeding the ion temperature T i , the magnitude of the fluctuations increases with the electron plasma-to-cyclotron frequency ratio ω pe /Ω ce , reaching realistic values at ω pe /Ω ce ≳ 30. The large-amplitude fluctuations in the simulations are shown to be associated with electrostatic solitary structures, such as ion phase-space holes. In the cases where upstream temperature ratio is reversed, the magnitude of the fluctuations remains small.

Source: The Astrophysical Journal

DOI: 10.3847/1538-4357/ae06a9

Authors: Vadim Roytershteyn, Lynn B. Wilson, Li-Jen Chen, Michael Gedalin, Nikolai Pogorelov

Institutions: Space Science Institute, Goddard Space Flight Center, Heliophysics Science Division, Ben-Gurion University of the Negev, University of Alabama in Huntsville

Language: English

Topic: Solar and Space Plasma Dynamics

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $4,499

Funder: National Science Foundation