Non-damping oscillations at flaring loops |
|
Dong Li Submitted: 2018-06-22 08:01
We investigate the properties of non-damping oscillations at flaring loops using observations from the IRIS, SDO, Fermi and GOES. The double-component Gaussian fitting method is used to extract the line prole of Fe XXI 1354.08 A at the spectral window. The quasi-periodicity of loop oscillations are identified in the Fourier and wavelet spectra. A quasi-period of about 40 s is detected in the
line properties of Fe XXI 1354.08 A, hard X-ray emissions in GOES 1-8 A derivative, and Fermi 26-50 keV. The Doppler velocity and line width oscillate in phase, while a phase shift of about Pi/2 is detected between the Doppler velocity and peak intensity. The amplitudes of Doppler velocity and line width oscillation are about 2.2 km s-1 and 1.9 km s-1, respectively, while peak intensity oscillate with
amplitude at about 3.6% of the background emission. The observations show that 40 s oscillations are not
damped significantly, which could be linked to the global kink modes of flaring loops. The magnetic field strengths at flaring loops are estimated to be about 120-170 G using the MHD seismology diagnostics and the flux rope insertion method. Meanwhile, a quasi-period of about 155 s is identified in the Doppler velocity and peak intensity of the Fe xxi 1354.08 A line emission, and AIA 131 A intensity, and it is likely a signature of recurring downflows after chromospheric evaporation along the
flaring loops.
Authors: Li, D.; Yuan, D.; Su, Y. N.; Zhang, Q. M.; Su, W.; Ning, Z. J.
Projects: Fermi/GBM,IRIS
|
Publication Status: accepted by A&A
Last Modified: 2018-06-22 11:42
|
 
 
 
 
|
|