$\delta$-Sunspot Formation in Simulation of Active-Region-Scale Flux Emergence

摘要: $\delta$-sunspots, with highly complex magnetic structures, are very productive in energetic eruptive events, such as X-class flares and homologous eruptions. We here study the formation of structures by numerical simulations flux emergence from convection zone into corona an active-region-scale domain. In our simulation, two pairs bipolar sunspots form on surface, originating buoyant segments a single subsurface twisted rope, following approach Toriumi et al. (2014). Expansion rotation emerging fields bipoles drive opposite polarities each other apparent rotating motion, producing compact $\delta$-sunspot sharp polarity inversion line. The realistic-scale domain produces patterns similar to those formed observations, e.g. inverted against Hale's law, curvilinear motion spot, strong transverse field sheared velocity at PIL. Strong current builds up PIL, giving rise reconnection, which coronal connectivity non-potential Delta-spot overlaid more relaxed connecting ends.