Plasmoid-fed prominence formation (PF$^2$) during flux rope eruption

Abstract

We report a new, plasmoid-fed scenario for the formation of an eruptive prominence (PF 2 ), involving reconnection and condensation. We use grid-adaptive resistive two-and-a-half-dimensional magnetohydrodynamic (MHD) simulations in a chromosphere-to-corona setup to resolve this plasmoid-fed scenario. We study a pre-existing flux rope (FR) in the low corona that suddenly erupts due to catastrophe, which also drives a fast shock above the erupting FR. A current sheet (CS) forms underneath the erupting FR, with chromospheric matter squeezed into it. The plasmoid instability occurs and multiple magnetic islands appear in the CS once the Lundquist number reaches ∼ 3.5 × 10 4 . The remnant chromospheric matter in the CS is then transferred to the FR by these newly formed magnetic islands. The dense and cool mass transported by the islands accumulates in the bottom of the FR, thereby forming a prominence during the eruption phase. More coronal plasma continuously condenses into the prominence due to the thermal instability as the FR rises. Due to the fine structure brought in by the PF 2 process, the model naturally forms filament threads, aligned above the polarity inversion line. Synthetic views at our resolution of 15km show many details that may be verified in future high-resolution observations.