Fine structure of type III solar radio bursts from Langmuir wave motion in turbulent plasma

Abstract

The Sun frequently accelerates near-relativistic electron beams that travel out through the solar corona and interplanetary space. Interacting with their plasma environment, these beams produce type III radio bursts, the brightest astrophysical radio sources seen from the Earth. The formation and motion of type III fine frequency structures is a puzzle but is commonly believed to be related to plasma turbulence in the solar corona and solar wind. Combining a theoretical framework with kinetic simulations and high-resolution radio type III observations using the Low Frequency Array, we quantitatively show that the fine structures are caused by the moving intense clumps of Langmuir waves in a turbulent medium. Our results show how type III fine structure can be used to remotely analyse the intensity and spectrum of compressive density fluctuations, and can infer ambient temperatures in astrophysical plasma, both significantly expanding the current diagnostic potential of solar radio emission.

22 pages, 9 figures

References in corpus (7)

• Density Fluctuations in the Solar Wind Based on Type III Radio Bursts Observed by Parker Solar Probe
• Dynamics of electron beams in the inhomogeneous solar corona plasma
• The Low-High-Low Trend of Type III Radio Burst Starting Frequencies and Solar Flare Hard X-rays
• Langmuir Wave Electric Fields Induced by Electron Beams in the Heliosphere
• A study of density modulation index in the inner heliospheric solar wind during solar cycle 23
• Turbulent density fluctuations and proton heating rate in the solar wind from 9-20~R_{\odot}
• Solar plasma radio emission in the presence of imbalanced turbulence of kinetic-scale Alfvén waves

Cited by in corpus (15)

• Defining the Middle Corona
• An Anisotropic Density Turbulence Model from the Sun to 1 au Derived From Radio Observations
• Fine structures of radio bursts from flare star AD Leo with FAST observations
• Tracking a beam of electrons from the low solar corona into interplanetary space with the Low Frequency Array, Parker Solar Probe and 1 au spacecraft
• Structured type III radio bursts observed in interplanetary space
• Source positions of an interplanetary type III radio burst and anisotropic radio-wave scattering
• First Results from the REAL-time Transient Acquisition backend (REALTA) at the Irish LOFAR station
• Detection of weak ubiquitous impulsive nonthermal emissions from the solar corona
• First Frequency-Time-Resolved Imaging Spectroscopy Observations of Solar Radio Spikes
• Tracing the Heliospheric Magnetic Field via Anisotropic Radio-Wave Scattering
• Magnetic Field Geometry and Anisotropic Scattering Effects on Solar Radio Burst Observations
• The frequency ratio and time delay of solar radio emissions with fundamental and harmonic components
• Electromagnetic radiation by turbulent, magnetized and randomly inhomogeneous solar radio sources generated by electron beams
• Ion-scale Turbulence and Energy Cascade Rate in the Solar Corona and Inner Heliosphere
• Observations of shock propagation through turbulent plasma in the solar corona