The Skew of X-Ray Coronal Loops Overlying Hα Filaments

Abstract

The basic magnetic structure surrounding photospheric magnetic inversion lines, where filament channels have developed, is comprised of axial fields along the inversion zone and overlying coronal arcades [Martin, 1990]. The overlying arcade is thought to be a necessary condition for the development of the axial fields of filament channels [Martin, 1990]. The formation of filament channel axial fields is evidenced by the alignment of the chromospheric fibrils and is known to be a condition for the formation of filaments [Martin, 1990]. Observations have recently led to a general empirical model of Hα filament channels [Martin, Bilimoria and Tracadas, 1994] and filaments [Martin and Echols, 1994]. One of the significant features of this model is that filaments and filament channels fall into two categories, having “dextral” and “sinistral” chirality, recognizable by the systematic orientation of the “barbs” along their two sides. Viewed along the axis, and away from the observer, a filament is called dextral or sinistral when the barbs veer to the right or the left, respectively, away from the filament axis.