Transfer of Twists from a Mini-filament to Large-scale Loops by Magnetic Reconnection

Abstract With high spatial and temporal resolution, Hα data from the New Vacuum Solar Telescope, X-ray images from the X-ray telescope on board Hinode and simultaneous observations from the Solar Dynamics Observatory, we present multiwavelength observations of the interaction between a mini-filament (MF) and its overlying large-scale active-region loops (ARLs) that occurred in AR 12497 on 2016 February 13. The MF was activated by the convergence and cancellation of the magnetic flux under it. Brightenings first appeared at the junction of the MF and its overlying large-scale ARLs. A blowout jet with some plasma blobs was observed to move along the newly formed large-scale ARLs, and caused the oscillations of these loops. The blowout jet exhibited a counterclockwise rotation due to the untwisting motion of the MF, suggesting that the twist is transferred from the MF to the ARLs. The transferred twist was measured to be about 0.34–0.52 turn. During the interaction progress, a group of hot loops formed in the high-temperature wavelength (94 Å). These hot loops connected the west footpoints of the original ARLs and the east footpoints of the MF. The differential emission measure analysis demonstrated that these hot loops contained a high-temperature component (∼8 MK). Meanwhile the footpoints of the ARLs were finally shifted to the west footpoint of the MF. These observations suggest that magnetic reconnection takes place between the MF and its overlying large-scale ARLs and results in a confined untwisting blowout jet.