Abstracts Details


First Name * : Konstantinos
Last Name * : Karampelas
Affiliation * : KU Leuven
Abstract Type * : Oral
Title * : Amplitudes and energy fluxes of simulated decay-less kink oscillations.
Author(s) * : K. Karampelas [1] , T. Van Doorsselaere [1] , D. Pascoe [1], M. Guo [2], [1], and Patrick Antolin [3]
Abstract Session * : Fundamental plasma processes
Abstract * : Recent observations with the Atmospheric Imaging Assembly (AIA) instrument on the SDO spacecraft have revealed the existence of low-amplitude decay-less transverse oscillations in coronal loops. These oscillations do not seem to be connected to any external phenomena like flares or coronal mass ejections, and show significantly lower amplitudes than the externally excited decaying oscillations. Numerical studies have managed to reproduce such decay-less oscillations in the form of footpoint driven standing waves in loops, and to treat them as a possible mechanism for wave heating of the solar atmosphere. Our aim is to investigate the correlation between the observed amplitudes of the oscillations and input the energy flux from different drivers. By performing 3D MHD simulations of straight flux tubes in a coronal environment, we study the manifestation of the Kelvin-Helmholtz instability in oscillating loops, and we construct synthetic images at different spectral lines with the use of the FoMo code. Our past studies show that the development of the instability leads to mixing of plasma between the loop and its environment, while also disrupting the initial monolithic loop profile into a turbulent one. The out-of-phase movements due to the KHI, and the LOS effects prevent us from establishing a clear correlation between the input energy flux from the drivers and the oscillation amplitudes from the synthetic emission maps. Stronger drivers lead to higher vales of the line width estimated energy fluxes, while estimations are affected by the LOS angle, favouring combined analysis of imaging and spectroscopic data for single oscillating loops. We conclude that the underlying energy fluxes from low amplitude decay-less kink oscillations can be of the order of the radiative losses for the Quiet Sun.