The Role of Twist in the Emergence of Kinked Flux Ropes and the Formation of Delta-Spots

It has been observationally well established that the magnetic configurations most favorable to producing energetic flaring events reside in delta-spots, a class of sunspots defined as having opposite polarity umbrae sharing a common penumbra. They are frequently characterized by extreme compactness, strong rotation and anti-Hale orientation. Numerous studies have shown that nearly all of the largest solar flares originate in delta-spots, making the understanding of these structures a fundamental step in predicting space weather. Despite their important influence on the space environment, surprisingly little is understood about the origin and behavior of delta-spots. Theoretical work suggests that the kink instability of emerging flux ropes is a promising candidate to explain their formation, as it reproduces their key characteristics very well. To date, however, a systematic study of the behavior of emerging, kinking flux ropes as relates to observed delta-spot signatures has not been undertaken. In this paper, we test this theoretical model by simulating the emergence of highly twisted, kink-unstable flux ropes from the convection zone into the corona, and comparing their photospheric properties to those of emerged weakly twisted, kink-stable flux ropes. We show that the photospheric manifestations of the emergence of highly twisted flux ropes closely match the observed properties of delta-spots, and we discuss the resulting implications for observations.