Observations and MHD modelling of a confined filament eruption & helical jet
Abstract
To understand how filament eruptions produce coronal mass ejections, it is useful to understand under what conditions such eruptions fail to escape the low corona. In this work we used a combination of ground and space-based observatories to study a small filament eruption that remained confined within an active region. The filament forms beneath the domed separatrix of a coronal null point with a closed outer spine. Soon after the filament starts to erupt, the upward moving filament material becomes redirected along coronal loops nearby the outer spine in the form of a helical jet. SST/CRISP captured at high spatial resolution and temporal cadence the crucial moments when the transfer of filament material and the development of rotation takes place, showing this phase in exceptional detail. We compared the observations with an MHD simulation of a breakout jet in a similar closed-field topology. In the model the filament channel erupts via runaway breakout reconnection at the null, launching a confined helical jet when the erupting flux rope reaches the null and is reconnected on to overlying coronal loops. This essentially redirects the upward momentum of the eruption along these loops and back to the surface. We find excellent qualitative agreement with the observed filament material evolution and associated loop and surface brightenings in AIA. We conclude that the breakout jet mechanism provides an intuitive explanation for such confined eruptions. We gratefully acknowledge support from an RAS fellowship (PFW) and an STFC studentship (LD).
- Publication:
-
Solar Heliospheric and INterplanetary Environment (SHINE 2019)
- Pub Date:
- May 2019
- Bibcode:
- 2019shin.confE.106F