Sloshing Oscillations in Hot Coronal Loops Associated with M-Class Flares

Abstract

Analysis of more than 300 M-class solar flares observed with the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory in the 131 Å channel, revealed 16 events of sloshing oscillations in hot solar coronal loops. Time–distance maps made along the loops demonstrated EUV emission intensity blobs bouncing between the footpoints, i.e., showing characteristic zigzagging patterns, of the size shorter than 25% of the loop length. The oscillation periods are found to range from about 150 s to 1325 s. The average phase speed, estimated as the ratio of the oscillation period and the loop length, is about 500 km s⁻¹. Parameters of the oscillations are consistent with the interpretation in terms of multi-harmonic slow magnetoacoustic oscillations.