Estimation of the physical parameters of a CME at high coronal heights using low frequency radio observations

Abstract

Measuring the physical parameters of Coronal Mass Ejections (CMEs), particularly their entrained magnetic field, is crucial for understanding their physics and for assessing their geo-effectiveness. At the moment, only remote sensing techniques can probe these quantities in the corona, the region where CMEs form and acquire their defining characteristics. Radio observations offer the most direct means for estimating the magnetic field when gyrosynchontron emission is detected. In this work we measure various CME plasma parameters, including its magnetic field, by modelling the gyrosynchrotron emission from a CME. The dense spectral coverage over a wide frequency range provided by the Murchison Widefield Array (MWA) affords a much better spectral sampling than possible before. The MWA images also provide much higher imaging dynamic range, enabling us to image these weak emissions. Hence we are able to detect radio emission from a CME at larger distances ($4.73R_{\odot }$) than have been reported before. The flux densities reported here are amongst the lowest measured in similar works. Our ability to make extensive measurements on a slow and otherwise unremarkable CME suggest that with the availability of data from the new generation instruments like the MWA, it should now be possible to make routine direct detections of radio counterparts of CMEs.

References in corpus (13)

• A Review of Solar Type III Radio Bursts
• Element Abundances: A New Diagnostic for the Solar Wind
• Fermi-LAT Observations of High-energy Behind-the-limb Solar Flares
• Estimation of a Coronal Mass Ejection Magnetic Field Strength using Radio Observations of Gyrosynchrotron Radiation
• Onsets and spectra of impulsive solar energetic electron events observed near the Earth
• 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
• Evolution of the Solar Flare Energetic Electrons in the Inhomogeneous Inner Heliosphere
• 4D Data Cubes from Radio-Interferometric Spectroscopic Snapshot Imaging
• The Low-Frequency Solar Corona in Circular Polarization
• Unsupervised generation of high dynamic range solar images: A novel algorithm for self-calibration of interferometry data
• Solar type II radio bursts associated with CME expansions as shown by EUV waves
• Comprehensive Characterization of Solar Eruptions With Remote and In-Situ Observations, and Modeling: The Major Solar Events on 4 November 2015

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