Physics

Corona (planetary geology)

Solar radio

Mechanics

Plasma oscillation

Solar wind

Astronomy

Interplanetary spaceflight

Turbulence

Astrophysical plasma

Langmuir Turbulence

Venus

Astrophysics

Quantum mechanics

Plasma

Computational physics

Astrobiology

Radio wave

Interplanetary medium

Nature Astronomy

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 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, substantially expanding the current diagnostic potential of solar radio emission. Fine frequency structures of type III radio bursts are caused by the moving of intense clumps of Langmuir waves in a turbulent medium. Analysis of these structures can infer properties of the coronal and solar wind plasma and its density fluctuations.

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