Low frequency observations of transient quasi-periodic radio emission from the solar atmosphere

Abstract

We report low frequency observations of the quasi-periodic, circularly polarized, harmonic type III radio bursts whose associated sunspot active regions were located close to the solar limb. The measured periodicity of the bursts at 80 MHz was $\approx$ 5.2 s and their average degree of circular polarization ($dcp$) was $\approx 0.12$. We calculated the associated magnetic field $B$ : (1) using the empirical relationship between the $dcp$ and $B$ for the harmonic type III emission, and (2) from the observed quasi-periodicity of the bursts. Both the methods result in $B\approx$ 4.2 G at the location of the 80 MHz plasma level (radial distance $r\approx 1.3{\mathrm{R}}_{\odot }$) in the active region corona.

Published in Astrophysical Journal

Cited by in corpus (18)

• Statistics and Polarization of Type III Radio Bursts Observed in the Inner Heliosphere
• An estimate of the magnetic field strength associated with a solar coronal mass ejection from low frequency radio observations
• Strength of the Solar Coronal Magnetic field - A Comparison of Independent Estimates Using Contemporaneous Radio and White-light Observations
• A Statistical Study of Solar Radio Type III Bursts and Space Weather Implication
• Solar Coronal Magnetic Fields and Sensitivity Requirements for Spectropolarimetry Channel of VELC Onboard Aditya-L1
• Trends and Characteristics of High-Frequency Type II Bursts Detected by CALLISTO Spectrometers
• A Statistical Study of Low-frequency Solar Radio Type-III Bursts
• Observation of a Metric Type N Solar Radio Burst
• Solar coronal density turbulence and magnetic field strength at the source regions of two successive metric type II radio bursts
• Eruption of EUV Hot-Channel near Solar Limb and Associated Moving Type-IV Radio Burst
• New results on the direct observations of thermal radio emission from a solar coronal mass ejection
• Low frequency radio observations of the `quiet' corona during the descending phase of sunspot cycle 24
• Broadband Polarized Radio Emission Detected from Starlink Satellites Below 100 MHz with NenuFAR
• Preparing for Solar and Heliospheric Science with the SKAO: An Indian Perspective
• First Robust Detection of Linear Polarization from Metric Solar Emissions: Challenging Established Paradigms
• Extended scenarios for solar radio emissions with downshifted electron beam plasma excitations
• Spectral Analysis of Solar Radio Type III Bursts from 20 kHz to 410 MHz
• Radio Burst and Circular Polarization Studies of the Solar Corona at Low Frequencies