Title: Observation and modeling of decayless oscillations in short coronal loops
This seminar is organised by KU Leuven's Center for mathematical Plasma-Astrophysics (CmPA).
Speaker: Yuhang Gao (KU Leuven)
Abstract: Decayless kink oscillations of coronal loops (or decayless oscillations for short) have attracted great attention since their discovery. Period of these oscillations was found to scale with the loop length. Recently, high frequency decayless oscillations are reported in two short loops with lengths of 4.5 and 11 Mm located in quiet Sun region of the corona. The period and wavelength match the linear scaling found before. In this study, we identified transverse oscillations in some coronal bright points (CBPs) consisting of short loops using 171 Å images taken by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. We analyzed 23 CBPs and found 31 oscillation events without any apparent damping in 16 of them. Relationships between oscillation periods and loop lengths were also examined, but there is no linear correlation between them. Meanwhile, histogram of the period shows a peak at about 5 min, suggesting a possible relationship with photospheric p-modes. To explain these observations, we made a 3D MHD model with an inclined short loop driven by p-modes at one footpoint. We found that the excited transverse oscillations have two regimes with periods of about 40 s and 5 min, respectively. We suggested that the first regime corresponds to eigenmode oscillation, while the second one is driven directly by p-modes.
The seminar will be held in a hybrid mode, in person in building 200B, room 00.16 and transmitted online using the following permanent Blackboard Collaborate link, that can be used for all the upcoming seminars in this academic year:
https://eu.bbcollab.com/guest/6fc7259fc2ba4f29af721ccb6a19eefd
