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Aabha Monga

Publications and source records attributed to Aabha Monga.

2 recordsLinked to original sources

Driving mechanisms of solar active region geysers: The role of interacting magnetic flux

Active region recurrent jets are manifestations of episodic magnetic energy release processes driven by complex interactions in the lower solar atmosphere. While magnetic flux emergence and cancellation are widely recognized as key contributors to jet formation, the mechanisms behind repeated magnetic reconnection remain poorly understood. In this letter, we report a sequence of nine recurrent jets originating from active region AR 12715 during its decay phase, where the jet activity was associated with a complex distribution of fragmented magnetic flux. Non-linear force-free field (NLFFF) extrapolations reveal the presence of low-lying, current-carrying loops beneath overarching open magnetic fields near the jet footpoints. These magnetic structures were perturbed by (i) emerging flux elements and (ii) interactions between oppositely polarized moving magnetic features (MMFs). To interpret these observations, we compare them with 3D radiative MHD simulation from the Bifrost model, which reproduce jet formation driven by interacting bipolar MMFs, leading to subsequent flux cancellation in the photosphere. Our results emphasize the critical role of MMF-driven flux interactions in initiating and sustaining recurrent jet activity in active regions.

astro-ph.SR

On the partial eruption of a bifurcated solar filament structure

The partial eruption of a filament channel with bifurcated substructures is investigated using datasets obtained from both ground-based and space-borne facilities. Small-scale flux reconnection/cancellation events in the region triggered the pile-up of ambient magnetic field, observed as bright EUV loops in close proximity of the filament channel. This led to the formation of a V-shaped cusp structure at the site of interaction between the coalesced EUV loops and the filament channel, with the presence of distinct plasmoid structures and associated bidirectional flows. Analysis of imaging data from SDO/AIA further suggests the vertical split of the filament structure into two substructures. The perturbed upper branch of the filament structure rose up and erupted with the onset of an energetic GOES M1.4 flare at 04:30 UT on January 28, 2015. The estimated twist number and squashing factor obtained from nonlinear force free-field extrapolation of the magnetic field data support the vertical split in filament structure with high twist in upper substructure. The loss in equilibrium of the upper branch due to torus instability, implying this as a potential triggering mechanism of the observed partial eruption.

astro-ph.SR