Speaker
Description
The Hydrogen Balmer lines show enhanced emission in various energetic phenomena in the solar atmosphere. For example, the H$\alpha$ line shows complex wing enhancements in the Ellerman Bomb phenomenon. Recently, Ellerman bombs have been detected in the H$\beta$ line at high number densities in the Quiet Sun and it was concluded that these mark the ubiquitous presence of small-scale magnetic reconnection. In this work, we explore the diagnostic potential of the H$\epsilon$ line, one of the shorter wavelength Balmer lines that promise detection of small-scale energetic events at higher spatial resolution than achieved before. H$\epsilon$ is located just redward of the strong Ca H line core which poses a challenge for the understanding of the spectral line formation. To understand the formation of H$\epsilon$, especially the transition from absorption to emission line, we investigate the line formation using 3D radiative MHD Bifrost simulations and NLTE forward modelling with RH. The locations where H$\epsilon$ goes into emission mark regions of steep chromospheric temperature enhancements and indicate regions where magnetic energy is released. H$\epsilon$ could be therefore a valuable tracer for small-scale energetic events in the solar atmosphere.
