Spatial Position of Magnetic Flux Ropes in Flare Active Regions with and without Coronal Mass Ejections

Abstract

Using statistics from 15 X-ray class M flare events, the features of the position and orientation of magnetic flux ropes in the general spatial structure of the magnetic field of the active regions (ARs) during flares and coronal mass ejections (CME) were studied by reconstructing the coronal magnetic field from the photosphere to the corona (NLFFF extrapolation) for eruptive (with CME) and noneruptive (without CME) active regions. In the considered ARs the most powerful magnetic flux ropes are located near the center of brightness of the microwave flare source. However, weaker flux ropes also exist in other places of the AR. It is shown that in all events without CME, the most powerful ropes are located quasi-perpendicular to the overlying magnetic field lines (the ropes are “closed” by the external field). Various scenarios are observed in CME events: (1) the flux ropes are surrounded by an open magnetic field configuration (three events); (2) the flux ropes are oriented at small angles, quasi-parallel, to the overlying magnetic field lines (three events); (3) the flux ropes are oriented quasi-perpendicular to the external magnetic field (2 events).