000007167 001__ 7167
000007167 005__ 20250102154202.0
000007167 0247_ $$2DOI$$a10.1051/0004-6361/202451684 
000007167 037__ $$aSCART-2025-0004
000007167 100__ $$aLim, Daye
000007167 245__ $$aUndersampling effects on observed periods of coronal oscillations
000007167 260__ $$c2024
000007167 520__ $$aContext. Recent observations of decayless transverse oscillations have revealed two branches in the relationship between period and loop length. One is a linear relationship, interpreted as a standing mode, while the other shows almost no correlation and has not yet been interpreted conclusively. Aims. We investigated the undersampling effect on observed periods of decayless oscillations. Methods. We considered oscillating coronal loops that closely follow the observed loop length distribution. Assuming that all oscil- lations are standing waves, we modelled a signal that represents decayless oscillations where the period is proportional to the loop length and the amplitude and phase are randomly drawn. We generated a downsampled signal from the original signal by considering different sample rates that mimic temporal cadences of telescopes, and analysed the periods for sampled signals using the fast Fourier transform. Results. When the sampling cadence approaches the actual oscillation period, there is a greater tendency to overestimate the periods in short loops. We find the same two branches in the relationship between loop length and period of the sampled signals as those seen in the observations. Conclusions. We find that long periods of decayless oscillations occurring in short loops could be the result of undersampling.
000007167 594__ $$aSTCE
000007167 6531_ $$aEUI
000007167 6531_ $$atransverse oscillations
000007167 6531_ $$awaves
000007167 700__ $$aVan Doorsselaere, Tom
000007167 700__ $$aNakariakov, Valery M.
000007167 700__ $$aKolotkov, Dmitrii Y.
000007167 700__ $$aGao, Yuhang
000007167 700__ $$aBerghmans, David
000007167 773__ $$nid.L8$$pAstronomy & Astrophysics$$v690$$y2024
000007167 8560_ $$fdavid.berghmans@ksb-orb.be
000007167 85642 $$ahttps://arxiv.org/pdf/2409.12095
000007167 85642 $$ahttps://www.aanda.org/articles/aa/pdf/2024/10/aa51684-24.pdf
000007167 905__ $$apublished in
000007167 980__ $$aREFERD