Pseudostreamer influence on flux rope evolution

SAHADE, A., CÉCERE, M., SIEYRA, V., KRAUSE, G., CREMADE, H., COSTA, A.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2022

0004-6361

Context. Pseudostreamers (PSs) are coronal magnetic structures formed by arcs of twin loops capped by magnetic field lines fromcoronal holes of the same polarity that meet at a central spine. They contain a single magnetic null point in the spine, just above theclosed field lines, which potentially influences the evolution of nearby flux ropes (FRs).Aims. To understand the early evolution of a FR under the PS influence, parametric studies are necessary. To focus on the net effectof the PS on ejection and non-radial motions, the scenario studied must not be influenced by other magnetic structures.Methods. We performed numerical simulations in which a FR structure is in the vicinity of a PS magnetic configuration. The combinedmagnetic field of the PS and the FR results in the formation of two magnetic null points. We evolve this magnetic scenario bynumerically solving the magnetohydrodynamic equations in 2.5D. The simulation consider a fully ionised compressible ideal plasmain the presence of a gravitational field and a stratified atmosphere.Results. We find that the dynamic behaviour of the FR can be categorised into three different classes based on the FR trajectories andwhether it is eruptive or confined. Our analysis indicates that the total unsigned magnetic flux of the magnetic cage enclosing the FRis a key parameter in defining whether eruption occurs. Moreover, the magnetic null points are decisive in the direction and intensityof the FR deflection and their hierarchy depends on the topological arrangement of the scenario.