Kink oscillations of magnetic flux tubes in presence of resistivity

Abstract

ABSTRACTKink oscillations in the solar coronal flux tubes are among the best seismological tools for estimating the unknown parameters of the solar corona. Here, we study the effect of resistivity on the linear evolution of magnetohydrodynamic (MHD) kink waves in magnetic flux tubes with transverse inhomogeneity in the plasma density. In thin tube thin boundary approximation, we obtain the well-known resistive spectrum of Alfvén continuum modes with a semi-analytical method and study the relative importance of the eigenmodes in the spectrum. As shown in previous studies, the quasi-mode solution of ideal MHD appears in the spectrum. Results show that while the internal and external homogeneous regions of the flux tube oscillate dominantly in quasi-mode in the inhomogeneous region in each magnetic surface a different combination of resistive eigenmodes contributes to the perturbations. Comparing the results obtained here with those obtained previously in the same configuration for a viscous plasma shows that resistivity is less efficient than viscosity in transforming the energy of the wave to heat.