English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Aims. We investigate the configuration of a complex flux rope above a{\delta} sunspot region in NOAA AR 11515, and its eruptive expansion during aconfined M5.3-class flare.  Methods. We study the formation of the {\delta} sunspot using continuumintensity images and photospheric vector magnetograms provided by SDO/HMI. Weuse EUV and UV images provided by SDO/AIA, and hard X-ray emission recorded byRHESSI to investigate the eruptive details. The coronal magnetic field isextrapolated with a non-linear force free field (NLFFF) method, based on whichthe flux rope is identified by calculating the twist number Tw and squashingfactor Q. We search the null point via a modified Powell hybrid method.  Results. The collision between two emerging spot groups form the {\delta}sunspot. A bald patch (BP) forms at the collision location, above which acomplex flux rope is identified. The flux rope has multiple layers, with onecompact end and one bifurcated end, having Tw decreasing from the core to theboundary. A null point is located above the flux rope. The eruptive processconsists of precursor flaring at a 'v'-shaped coronal structure, rise of thefilament, and flaring below the filament, corresponding well with the NLFFFtopological structures, including the null point and the flux rope with BP andhyperbolic flux tube (HFT). Two sets of post-flare loops and three flareribbons support the bifurcation configuration of the flux rope.  Conclusions. The precursor reconnection, which occurs at the null point,weakens the overlying confinement to allow the flux rope to rise, fitting thebreakout model. The main phase reconnection, which may occur at the BP or HFT,facilitates the flux rope rising. The results suggest that the {\delta} spotconfiguration presents an environment prone to the formation of complexmagnetic configurations which will work together to produce activities.

The configuration and failed eruption of a complex magnetic flux rope above a {\delta} sunspot region