Resonant absorption as a damping mechanism for the transverse oscillations of the coronal loops observed by SDO/AIA

TL;DR

This study analyzes transverse oscillations in solar coronal loops observed by SDO/AIA, demonstrating that resonant absorption is the primary damping mechanism for these oscillations, with detailed measurements of periods and damping times.

Contribution

It provides observational evidence that resonant absorption causes damping of transverse coronal loop oscillations, with specific measurements of periods and damping times from EUV data.

Findings

Damping quality ratios indicate strong damping regime.

Resonant absorption identified as main damping mechanism.

Measured periods range from 19 to 81 minutes.

Abstract

Solar coronal loops represent the variety of fast, intermediate, and slow normal mode oscillations. In this study, the transverse oscillations of the loops with a few-minutes period and also with damping caused by the resonant absorption were analyzed using extreme ultraviolet (EUV) images of the Sun. We employed the 171 $\AA$ data recorded by Solar Dynamic Observatory (SDO)/Atmospheric Imaging Assembly (AIA) to analyze the parameters of coronal loop oscillations such as period, damping time, loop length, and loop width. For the loop observed on 11 October 2013, the period and the damping of this loop are obtained to be 19 and 70 minutes, respectively. The damping quality, the ratio of the damping time to the period, is computed about 3.6. The period and damping time for the extracted loop recorded on 22 January 2013 are about 81 and 6.79 minutes, respectively. The damping quality is also computed as 12. It can be concluded that the damping of the transverse oscillations of the loops is in the strong damping regime, so resonant absorption would be the main reason for the damping.