Resonantly damped oscillations of elliptically shaped stratified emerging coronal loops

Abstract

The effects of both elliptical shape and stage of emergence of the coronal loop on the resonant absorption of standing kink oscillations are studied. To do so, a typical coronal loop is modeled as a zero-beta longitudinally stratified cylindrical magnetic flux tube. We developed the connection formulae for the resonant absorption of standing transversal oscillations of a coronal loop with an elliptical shape, at various stages of its emergence. Using the connection formulae, the dispersion relation is derived and solved numerically to obtain the frequencies and damping rates of the fundamental and first-overtone kink modes. Our numerical results show that both the elliptical shape and stage of emergence of the loop alter the frequencies and damping rates of the tube as well as the ratio of frequencies of the fundamental and its first-overtone modes. However, the ratio of the oscillation frequency to the damping rate is not affected by the tube shape and stage of its emergence and also is independent of the density stratification parameter.

19 pages, 9 figures

References in corpus (5)

• On the nature of kink MHD waves in magnetic flux tubes
• The Effect of Twisted Magnetic Field on the Period Ratio P_1/P_2 of Nonaxisymmetric MHD Waves
• The effect of twisted magnetic field on the resonant absorption of MHD waves in coronal loops
• The effects of twisted magnetic field on coronal loops oscillations and dissipation
• The effect of density stratification on the resonant absorption of MHD waves in coronal loops

Cited by in corpus (1)

• Resonant Absorption of Kink MHD Waves in Inclined and Asymmetric Coronal Loops