Filament Leg–Leg Reconnection as a Source of Prominent Supra-arcade Downflows

Jaroslav Dudík (1) , Guillaume Aulanier (2, 3) , Jana Kašparová (1) , Marian Karlický (1) , Alena Zemanová (1) , Juraj Lörinčík (4, 5) , Miloslav Druckmüller (6)

1 Ondřejov Observatory of the Prague Astronomical Institute
2 LPP - Laboratoire de Physique des Plasmas
3 RoCS - Rosseland Centre for Solar Physics
4 BAER - Bay Area Environmental Research Institute
5 LMSAL - Lockheed Martin Solar and Astrophysics Laboratory
6 Faculty of Mechanical Engineering [Brno]

We report on the interaction of the legs of the erupting filament of 2012 August 31 and associated prominent supra-arcade downflows (P-SADs) as observed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. We employ a number of image processing techniques to enhance weak interacting features. As the filament erupts, both legs stretch outwards. The positive-polarity leg also untwists and splits into two parts. The first part runs into the conjugate (negative-polarity) leg, tearing it apart. The second part then converges into the remnant of the conjugate leg, after which both weaken and finally disappear. All these episodes of interaction of oppositely oriented filament legs are followed by the appearance of P-SADs, seen in the on-disk projection to be shaped as loop tops, along with many weaker SADs. All SADs are preceded by hot supra-arcade downflowing loops. This observed evolution is consistent with the three-dimensional rr–rf (leg–leg) reconnection, where the erupting flux rope reconnects with itself. In our observations, as well as in some models, the reconnection in this geometry is found to be long lasting. It plays a substantial role in the evolution of the flux rope of the erupting filament and leads to prominent SADs.

Domaines: Astrophysique stellaire et solaire [astro-ph.SR]

Jaroslav Dudík, Guillaume Aulanier, Jana Kašparová, Marian Karlický, Alena Zemanová, et al.. Filament Leg–Leg Reconnection as a Source of Prominent Supra-arcade Downflows. The Astrophysical journal letters, 2022, 937 (1), pp.L10. ⟨10.3847/2041-8213/ac8eaf⟩. ⟨hal-04327003⟩