Wavelet Analysis of Oscillations in Quiescent Prominence
Authors:
A. Wiśniewska, K. Ichimoto, J. Koza, I. Kontogiannis, A. G. M. Pietrow, G. D. Muro, and P. Gomory
Image & caption:
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Image caption::
Cocoplot of the 3D global wavelet power spectrum (top left) with filters centered on the dominant period bands at 28–31 min (top right), 14–17 min (bottom left), and 3–6 min (bottom right). Cocoplots are overlaid with iso-contour of 750 ADU, i.e., the outermost one in Figs. 1 and 2. The color-bars show the power normalized to the respective maximum values.
Description:
On 26 September 2022, we observed a quiescent solar prominence with Hα imaging spectroscopy using the Solar Dynamics Doppler Imager (SDDI) on the SMART telescope. Unlike earlier works that detected 4- and 15-min oscillations through long-slit, 1D wavelet methods, we adapt the wavelet analysis to 3D data to explore the full prominence structure. Complementary data from SDO/AIA (304 ̊A, 171 ̊A) STEREO-A/EUVI (304 ̊A), and Solar Orbiter EUI/FSI (304 ̊A, 174 ̊A) enable a multi- view, multi-thermal investigation of wave periodicity across the prominence. Our aim is to characterize how oscillatory periods are distributed in plasma at different temperatures and viewing angles, thereby assessing wave propagation and variability throughout the prominence body. We analyze time series of Doppler signal from SMART/SDDI Hα observations alongside EUV intensity variations from space- based instruments. We detect oscillatory plasma motions with periods spanning 3–74 min. Strong periodicity at 20, 31, and 53 min dominate in neutral plasma (Hα), while 13- and 74-min oscillations are pronounced in the 304 ̊A passband, concentrated mainly in the central prominence. Additional short-period fluctuations include weaker 3–6 min oscillations and rapid 30 second transverse waves in Doppler signals near the solar surface. These findings highlight the richness of wave periodicity in quiescent prominences, revealing a dynamic superposition of long- and short-period oscillations, kink-like disturbances. This multi-instrument, 3D perspective advances our understanding of how prominence plasma supports and modulates diverse wave modes.
Reference:
The Astrophysical Journal 2025, Volume 995, Issue 1, id.17, 10 pp. , https://doi.org/10.3847/1538-4357/ae1ef4
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