Transverse Oscillations of Coronal Loops Induced by a Jet-Related Confined Flare on 11 July 2022

Abstract

In this article, we report the multiwavelength and multiview observations of transverse oscillations of two loop strands induced by a jet-related, confined flare in active region NOAA 13056 on 11 July 2022. The jet originates close to the right footpoint of the loops and propagates in the northeast direction. The average rise time and fall time of the jet are ≈ 11 and ≈ 13.5 minutes, so that the lifetime of the jet reaches ≈ 24.5 minutes. The rising motion of the jet is divided into two phases with average velocities of ≈ 164 and ≈ 546 km s⁻¹. The falling motion of the jet is coherent with an average velocity of ≈ 124 km s⁻¹. The transverse oscillations of the loops, lasting for 3 – 5 cycles, are of fundamental standing kink mode. The maximal initial amplitudes of the two strands are ≈ 5.8 and ≈ 4.9 Mm. The average periods are ≈ 405 s and ≈ 407 s. Both of the strands experience slow expansions during oscillations. The lower limits of the kink speed are \(895_{-17}^{+21}\) km s⁻¹ for loop_1 and \(891_{-35}^{+29}\) km s⁻¹ for loop_2, respectively. The corresponding lower limits of the Alfvén speed are estimated to be \(664_{-13}^{+16}\) km s⁻¹ and \(661_{-26}^{+22}\) km s⁻¹.