Modeling of gyrosynchrotron radio emission pulsations produced by magnetohydrodynamic loop oscillations in solar flares

Document Type

Article

Publication Date

4-1-2012

Abstract

A quantitative study of the observable radio signatures of the sausage, kink, and torsional magnetohydrodynamic (MHD) oscillation modes in flaring coronal loops is performed. Considering first non-zero order effect of these various MHD oscillation modes on the radio source parameters such as magnetic field, line of sight, plasma density and temperature, electron distribution function, and the source dimensions, we compute time-dependent radio emission (spectra and light curves). The radio light curves (of both flux density and degree of polarization) at all considered radio frequencies are then quantified in both time domain (via computation of the full modulation amplitude as a function of frequency) and in Fourier domain (oscillation spectra, phases, and partial modulation amplitude) to form the signatures specific to a particular oscillation mode and/or source parameter regime. We found that the parameter regime and the involved MHD mode can indeed be distinguished using the quantitative measures derived in the modeling. We apply the developed approach to analyze radio burst recorded by Owens Valley Solar Array and report possible detection of the sausage mode oscillation in one (partly occulted) flare and kink or torsional oscillations in another flare. © 2012. The American Astronomical Society. All rights reserved..

Identifier

84858741975 (Scopus)

Publication Title

Astrophysical Journal

External Full Text Location

https://doi.org/10.1088/0004-637X/748/2/140

e-ISSN

15384357

ISSN

0004637X

Issue

2

Volume

748

Grant

0707319

Fund Ref

National Science Foundation

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