Discussion paper: The kink oscillations of the thin nonuniform coronal loops

Abstract

[1]  MHD-oscillations of an inhomogeneous coronal loop consisting of a dense cord and a surrounding shell are investigated. Magnetic field in the cord is longitudinal and in the shell is azimuthal only. Usually the nonuniform field leads to the existence of resonance. However here we assume the resonance points non exist in the tube, i.e. the resonances are cutted. Our approach pursue a target - an investigation of an influence of the wave radiation on the tube oscillations. The resonant absorption of tube oscillation energy is eliminated. The same tube effectively radiate a magnetosonic waves into the environment and the Q -factor of the tube oscillations is small. The presented model can explain the fast damping of the coronal loop oscillations observed by the TRACE EUV channel.

Received 11 April 2006; accepted 17 August 2006; published 14 December 2006.

Keywords: Coronal loops; Kink oscillations; Magnetosonic waves.

Index Terms: 7509 Solar Physics, Astrophysics, and Astronomy: Corona; 7524 Solar Physics, Astrophysics, and Astronomy: Magnetic fields; 7836 Space Plasma Physics: MHD waves and instabilities.