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arXiv · 1611.05227

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

K. Sasikumar Raja·R. Ramesh
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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 $r \approx 1.3~\rm R_{\odot}$) in the active region corona.

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K. Sasikumar Raja, R. Ramesh. 2016-11-16. Low frequency observations of transient quasi-periodic radio emission from the solar atmosphere. https://doi.org/10.1088/0004-637x%2F775%2F1%2F38

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