A Scenario for the Fine Structures of Solar Type IIIb Radio Bursts Based on the Electron Cyclotron Maser Emission

Abstract

A scenario based on the electron cyclotron maser emission is proposed for the fine structures of solar radio emission in the present discussion. It is suggested that under certain conditions modulation of the ratio between the plasma frequency and electron gyro-frequency by ultra low frequency waves, which is a key parameter for excitation of the electron cyclotron maser instability, may lead to the intermittent emission of radio waves. As an example, the explanation of the observed fine-structure components in the solar type IIIb burst is discussed in detail. Three primary issues of the type IIIb bursts are addressed: 1) what is the physical mechanism that results in the intermittent emission elements that form a chain in the dynamic spectrum of type IIIb bursts, 2) what causes the split pair (or double stria) and the triple stria, 3) why in the events of fundamental-harmonic pair emission there is only IIIb-III, but IIIb-IIIb or III-IIIb cases are very rarely observed.

Published in The Astrophysical Journal

Cited by in corpus (10)

• Imaging Spectroscopy of Solar Radio Burst Fine Structures
• A type III radio burst automatic analysis system and statistic results for a half solar-cycle with the Nançay Decameter Array data
• Conditions for electron-cyclotron maser emission in the solar corona
• Interferometric Imaging with LOFAR Remote Baselines of the Fine Structures of a Solar Type IIIb Radio Burst
• Cyclotron maser emission from power-law electrons with strong pitch-angle anisotropy
• Forward Modeling of the Type III Radio Burst Exciter
• Decimetric emission 500${}^{\prime \prime }$ away from a flaring Site: Possible scenarios from $\text{GMRT}$ solar radio observations
• A Parametric Investigation on the Cyclotron Maser Instability Driven by Ring-beam Electrons with Intrinsic Alfvén Waves
• The frequency drift and fine structures of Solar S-bursts in the high frequency band of LOFAR
• Radio Burst and Circular Polarization Studies of the Solar Corona at Low Frequencies