Speaker
Description
Mini-filament eruptions are one of the most common small-scale transients in the solar atmosphere. They are small-scale analogs to solar filaments. They are associated with coronal jets that represent transient, collimated plasma ejections along open fields or far-reaching coronal loops. One particular type is blowout jets. These often come along with erupting loops or twisted filaments at the base of the jets. Consequently they have a more dynamic base and also often a wider spire than standart jets. Recently, a mini-filament eruption model has been put forward, in which a successful mini-filament eruption drives a blowout jet, while a partial or failed mini-filament eruption causes a standard jet. During blowout jets, many blobs have been observed and drawn much attention as they could provide evidence of the magnetic reconnection process, because these blobs are odten identified with plasmaoids in the current sheet. However, it is still difficult to observationally clarify the relation between the moving plasma blobs and magnetic reconnection. The clarification is mainly limited by the low spatio-temporal resolution of previous data. Here, with a combination of 174 Å images at high spatial resolution and high cadence taken by the Extreme Ultraviolet Imager on board Solar Orbiter and images of the Atmospheric Imaging Assembly on board Solar Dynamics Observatory, we investigate in detail an erupting mini-filament over a weak magnetic field region on 2022 March 4. During the eruption, two bright ribbons clearly appeared underneath the erupting mini-filament as it quickly ascended. Subsequently, some dark materials blew out when the erupting mini-filament interacted with the outer ambient loops, thus forming a blowout jet characterized by a widening spire. At the same time, a chain of small bright blobs with diameters of 1–2 Mm are intermittently expelled from the interaction region between the erupting mini-filament and ambient loops and propagated along the post-eruption loops toward the footpoints of the erupting fluxes at a speed of ~ 100 km/s. They have short lifetimes, varying from 30 s to 90 s. They also caused a semi-circular brightening structure. We suggest that these fast-moving blobs are evidence for magnetic reconnection. We performed a differential emission measure (DEM) analysis and found that various brightenings show plasma that is heated during the mini-filament eruption, e.g. two bright ribbons, footpoints of the ambient loops, and the interaction region. Based on the features aforementioned, we suggest that the mini-filament eruption first experiences internal reconnection that occurs underneath the erupting mini-filament and then external reconnection between the mini-filament and the ambient loops. The transfer of mass and magnetic flux from the erupting mini-filament to the ambient corona is mainly due to the external reconnection.
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