An estimate of the magnetic field strength associated with a solar coronal mass ejection from low frequency radio observations

Abstract

We report ground based, low frequency heliograph (80 MHz), spectral (85-35 MHz) and polarimeter (80 and 40 MHz) observations of drifting, non-thermal radio continuum associated with the `halo' coronal mass ejection (CME) that occurred in the solar atmosphere on 2013 March 15. The magnetic field strengths ($B$) near the radio source were estimated to be $B\approx 2.2\pm 0.4$ G at 80 MHz and $B\approx 1.4\pm 0.2$ G at 40 MHz. The corresponding radial distances ($r$) are $r\approx 1.9R_{\odot }$ (80 MHz) and $r\approx 2.2R_{\odot }$ (40 MHz).

Published in Astrophysical Journal