Hi-C and AIA observations of transverse magnetohydrodynamic waves in active regions⋆
Department of Mathematics & Information Sciences, Northumbria University, Newcastle Upon Tyne, NE1 8ST, UK
Received: 13 March 2013
Accepted: 30 April 2013
The recent launch of the High resolution Coronal imager (Hi-C) provided a unique opportunity of studying the EUV corona with unprecedented spatial resolution. We utilize these observations to investigate the properties of low-frequency (50−200 s) active region transverse waves, whose omnipresence had been suggested previously. The five-fold improvement in spatial resolution over SDO/AIA reveals coronal loops with widths 150−310 km and that these loops support transverse waves with displacement amplitudes <50 km. However, the results suggest that wave activity in the coronal loops is of low energy, with typical velocity amplitudes <3 km s-1. An extended time-series of SDO data suggests that low-energy wave behaviour is typical of the coronal structures both before and after the Hi-C observations.
Key words: Sun: corona / Sun: chromosphere / waves / magnetohydrodynamics (MHD)
Appendix A and five movies associated to Figs. A.2−A.6 are available in electronic form at http://www.aanda.org
© ESO, 2013