Description
Propagating slow magnetoacoustic waves, observed as intensity disturbances in extreme ultraviolet (EUV) emission, are powerful tools for magnetohydrodynamic (MHD) seismology. Their dispersive properties, phase speeds, and damping characteristics allow us to infer fundamental parameters such as temperature and magnetic field structure in coronal loops. Using observations from the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO), we investigate the fine structuring and driving mechanisms of propagating intensity disturbances guided by field-aligned plasma non-uniformities in the corona. Our analysis focuses on sunspot-anchored coronal fan structures, referred to as “feathers,” within active region 13100, observed on September 19, 2022.
Through time-distance analysis, we identify propagating disturbances with three distinct periods, 3.06 ± 0.04, 2.47 ± 0.02, and 2.82 ± 0.02 minutes across three separate feathers, and projected phase speeds consistent with propagating slow waves. Enhanced chromospheric oscillations at corresponding periods, detected in the 304 Å channel at the umbral footpoints of these structures, suggest a direct coupling between chromospheric and coronal dynamics.
These findings provide new insights into the interplay between chromospheric and coronal oscillations and their role in energy transport across atmospheric layers. Additionally, these results highlight the potential of slow waves for coronal seismology, particularly in constraining magnetic field geometry. This work opens several new avenues for research in simulations, theory, and observations, particularly in further investigating the driving mechanisms of these waves and their role in coronal dynamics.
