Determination of the coronal magnetic field by coronal loop oscillations

Determination of the coronal magnetic field by coronal loop oscillations

We develop a new method for the determination of the absolute value of the magnetic field strength in coronal closed magnetic structures, based on the analysis of flare-generated oscillations of coronal loops. Interpretation of the oscillations observed in terms of global standing kink waves allows to connect the period of the oscillations and the loops length with the magnetic field strength i...

The Damping of Coronal Loop Oscillations

Motivated by recent Transition Region and Coronal Explorer (TRACE) observations of damped oscillations in coronal loops, we consider analytically the motion of an inhomogeneous coronal magnetic tube of radius a in a zeroplasma. An initially perturbed tube may vibrate in its kink mode of oscillation, but those vibrations are damped. The damping is due to resonant absorption, acting in the inhomo...

Reconstruction of Solar Coronal Linear Force-Free Magnetic Field

Coronal magnetic field measurement using loop oscillations observed by Hinode/EIS

We report the first spectroscopic detection of a kink MHD oscillation of a solar coronal structure by the Extreme-Ultraviolet Imaging Spectrometer (EIS) on the Japanese Hinode satellite. The detected oscillation has an amplitude of 1 km s−1 in the Doppler shift of the FeXII 195 Å spectral line (1.3 MK), and a period of 296 s. The unique combination of EIS’s spectroscopic and imaging abilities e...

The effects of twisted magnetic field on coronal loop oscillations and dissipation

The standing magnetohydrodynamic (MHD) modes in a cylindrical incompressible magnetic flux tube modelled as a straight core surrounded by a magnetically twisted annulus, both embedded in a straight ambient external field, are considered. The dispersion relation for the MHD waves is derived and solved numerically to obtain the frequencies of both the kink (m = 1) and fluting (m = 2, 3) waves. Da...