Large scale simulations of solar type III radio bursts: flux density, drift rate, duration and bandwidth

Abstract

Non-thermal electrons accelerated in the solar corona can produce intense coherent radio emission, known as solar type III radio bursts. This intense radio emission is often observed from hundreds of MHz in the corona down to the tens of kHz range in interplanetary space. It involves a chain of physical processes from the generation of Langmuir waves to nonlinear processes of wave-wave interaction. We develop a self-consistent model to calculate radio emission from a non-thermal electron population over large frequency range, including the effects of electron transport, Langmuir wave-electron interaction, the evolution of Langmuir waves due to non-linear wave-wave interactions, Langmuir wave conversion into electromagnetic emission, and finally escape of the electromagnetic waves. For the first time we simulate escaping radio emission over a broad frequency range from 500~MHz down to a few MHz and infer key properties of the radio emission observed: the onset (starting) frequency, {identification as fundamental or harmonic emission}, peak flux density, instantaneous frequency bandwidth, and timescales for rise and decay. Comparing with the observations, these large scale simulations enable us to identify the processes governing the key type III solar radio burst characteristics.

References in corpus (5)

• Nonlinear development of electron-beam-driven weak turbulence in an inhomogeneous plasma
• Dynamics of electron beams in the solar corona plasma with density fluctuations
• Dynamics of electron beams in the inhomogeneous solar corona plasma
• Onsets and spectra of impulsive solar energetic electron events observed near the Earth
• Evolution of the Solar Flare Energetic Electrons in the Inhomogeneous Inner Heliosphere

Cited by in corpus (8)

• Imaging Spectroscopy of Type U and J Solar Radio Bursts with LOFAR
• How Electron Two-Stream Instability Drives Cyclic Langmuir Collapse and Continuous Coherent Emission
• Langmuir Wave Electric Fields Induced by Electron Beams in the Heliosphere
• Coronal type III radio bursts and their X-ray flare and interplanetary type III counterparts
• A comparison of weak-turbulence and PIC simulations of weak electron-beam plasma interaction
• Stopping Frequency of Type III Solar Radio Bursts in Expanding Magnetic Flux Tubes
• A Fokker-Planck Framework for Studying the Diffusion of Radio Burst Waves in the Solar Corona
• First observation of the solar Type III burst decay and its interpretation