Flare genesis experiment: Magnetic topology of Ellerman bombs

Flare Genesis Experiment (FGE), a balloon borne Observatory was launched in Antarctica on January 10 2000 and flew during 17 days. FGE consists of an 80 cm Cassegrain telescope with an F/1.5 ultralow-expansion glass primary mirror and a crystalline silicon secondary mirror. A helium-filled balloon carried the FGE to an altitude of 37 km (Bernasconi et al. 2000, 2001). We select among all the observations a set of high spatial and temporal resolution observations of an emerging active region with numerous Ellerman bombs (EBs). Statistical and morphology analysis have been performed. We demonstrate that Ellerman bombs are the result of magnetic reconnection in the low chromosphere by a magnetic topology analysis. The loci of EBs coincide with "bald patches" (BPs). BPs are regions where the vector field is tangential to the boundary (photosphere) along an inversion line. We conclude that emerging flux through the photosphere is achieved through resistive emergence of U loops connecting small ω loops before rising in the chromosphere and forming Arch Filament System (AFS).