Please use this identifier to cite or link to this item: http://hdl.handle.net/2248/6936
Title: Quasi-periodic oscillation of a coronal bright point
Authors: Samanta, T
Banerjee, D
Tian, H
Keywords: Sun: corona
Sun: magnetic fields
Sun: oscillations
Sun: transition region
Sun: UV radiation
Issue Date: 20-Jun-2015
Publisher: IOP Publishing
Citation: The Astrophysical Journal, Vol. 806, No. 2, 172
Abstract: Coronal bright points (BPs) are small-scale luminous features seen in the solar corona. Quasi-periodic brightenings are frequently observed in the BPs and are generally linked with underlying magnetic flux changes. We study the dynamics of a BP seen in the coronal hole using the Atmospheric Imaging Assembly images, the Helioseismic and Magnetic Imager magnetogram on board the Solar Dynamics Observatory, and spectroscopic data from the newly launched Interface Region Imaging Spectrograph (IRIS). The detailed analysis shows that the BP evolves throughout our observing period along with changes in underlying photospheric magnetic flux and shows periodic brightenings in different EUV and far-UV images. With the highest possible spectral and spatial resolution of IRIS, we attempted to identify the sources of these oscillations. IRIS sit-and-stare observation provided a unique opportunity to study the time evolution of one footpoint of the BP as the slit position crossed it. We noticed enhanced line profile asymmetry, enhanced line width, intensity enhancements, and large deviation from the average Doppler shift in the line profiles at specific instances, which indicate the presence of sudden flows along the line-of-sight direction. We propose that transition region explosive events originating from small-scale reconnections and the reconnection outflows are affecting the line profiles. The correlation between all these parameters is consistent with the repetitive reconnection scenario and could explain the quasi-periodic nature of the brightening.
Description: Restricted Access © IOP Publishing http://dx.doi.org/10.1088/0004-637X/806/2/172
URI: http://prints.iiap.res.in/handle/2248/6936
ISSN: 0004-637X
Appears in Collections:IIAP Publications

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