Fast and periodic propagating disturbances along coronal loops detected with EUI on board Solar Orbiter
Year: 2026
Type: article
Abstract: Context . Recent high-resolution observations from the Solar Orbiter mission can help detect the indirect signatures of heating at the smallest scales. Aims . In this work, we measure the properties and investigate the physical origin of propagating disturbances (PDs) in the intensity at the smallest resolvable scales with Solar Orbiter/EUI along coronal loops. Methods . We used two sequences of EUI/HRIEUV at high spatial (down to 125 per pixel) and temporal resolutions (5 of cadence). We placed slits along 13 active region (AR) coronal loops. We measured the plane-of-sky (PoS) velocities and the intensity perturbation damping along the slits of PDs. We also measured the periodicity of PDs in one slit by using a Fourier analysis. Results . We report the detection of PDs that have high PoS velocities ranging between 500 and 2000 (which we call “fast” PDs). They are only visible in the upper part of the coronal loops. The intensity increase associated with these fast PDs is on the order of 4–8% of the HRIEUV intensity, and we measured little to no damping of their intensity with distance. We also measured a peak in the Fourier power spectra at 2 min above the 95% confidence limit that is associated with fast PDs. The fast PDs are detected in the same coronal loops as PDs with a lower PoS velocity (70–90), which we refer to as “slow” PDs. Unlike the fast PDs, these slow PDs are only visible in the lower part of the coronal loop, and they show clear intensity damping. Conclusions . Slow PDs show properties consistent with slow magneto-acoustic modes or upflows. On the other hand, fast PDs cannot be explained by slow magneto-acoustic modes. Instead, they show properties consistent with fast flows induced by magnetic reconnection, current sheet generated by propagating transverse oscillations, and fast magnetohydrodynamics modes or Alfvén waves.
Source: Astronomy and Astrophysics
Institutions: Max Planck Institute for Solar System Research, Physikalisch-Meteorologisches Observatorium Davos, KU Leuven, Royal Observatory of Belgium, Université d'Orléans, Centre National de la Recherche Scientifique, Laboratoire de Physique et Chimie de l’Environnement et de l’Espace, Université Paris-Saclay, Institut d'Astrophysique Spatiale, Northumbria University, European Space Agency, European Space Research and Technology Centre, ETH Zurich
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
Funders: Bundesministerium für Wirtschaft und Klimaschutz, National Aeronautics and Space Administration, UK Space Agency, European Commission, Belgian Federal Science Policy Office, Centre National d’Etudes Spatiales, KU Leuven, Centre National de la Recherche Scientifique, Bundesministerium für Wirtschaft und Energie, Vlaamse regering, HORIZON EUROPE Framework Programme
OpenAlex ID: W7170032869