Polarization of decayless kink oscillations in a 3D MHD coronal loop model

Abstract

Decayless kink oscillations are frequently observed in solar coronal loops and are considered potential contributors to coronal heating. Despite the ubiquity of this wave phenomenon, its driving mechanism remains unclear. Studies to derive the polarization state of these oscillations, which would be a key to identifying the drivers, have been limited due to observational constraints. We analyze a 3D MHD simulation of coronal loops using the MURaM code. Synthetic extreme ultraviolet (EUV) emission maps, combined with velocity diagnostics, are used to identify and characterize transverse wave motions in the simulated loop structures. This is the first demonstration of decayless kink waves emerging self-consistently in a 3D MHD loop-in-a-box model. The simulation produces persistent, low-amplitude, decayless kink oscillations that closely match observed properties. These oscillations arise spontaneously, without any imposed periodic driver, and exhibit clear linear polarization with oscillation planes not aligned to the principal axes. The observed coherency of linear polarization with oscillation cycles favors a self-sustained or quasi-steady type wave driver over a stochastic or broadband source.

Accepted for publications in A&A

References in corpus (20)

• Multi-scale Gaussian normalization for solar image processing
• Extension of the MURaM radiative MHD code for coronal simulations
• Persistent Doppler shift oscillations observed with HINODE/EIS in the solar corona: spectroscopic signatures of Alfvenic waves and recurring upflows
• Decayless low-amplitude kink oscillations: a common phenomenon in the solar corona?
• Kink oscillations of coronal loops
• Transverse kink oscillations in the presence of twist
• Excitation of decay-less transverse oscillations of coronal loops by random motions
• Amplitudes and energy fluxes of simulated decayless kink oscillations
• The First 3D Coronal Loop Model Heated by MHD Waves against Radiative Losses
• Generating transverse loop oscillations through a steady-flow driver
• What drives decayless kink oscillations in active region coronal loops on the Sun?
• A solar coronal loop in a box: Energy generation and heating
• Flare induced decay-less transverse oscillations in solar coronal loops
• Transverse loop oscillations via vortex shedding: a self oscillating process
• A Statistical Investigation of Decayless Oscillations in Small-scale Coronal Loops Observed by Solar Orbiter/EUI
• Swirls in the Solar Corona
• Alfvénic motions arising from asymmetric acoustic wave drivers in solar magnetic structures
• Excitation and evolution of coronal oscillations in self-consistent 3D radiative MHD simulations of the solar atmosphere
• Decayless oscillations in 3D coronal loops excited by a power-law driver
• Doppler shifts of spectral lines formed in the solar transition region and corona