| Presentation Title: | Magnetic and electric field structures at the X point of an Ellerman bomb II |
| Author(s): | Tetsu Anan (NSO), Roberto Casini (HAO), Han Uitenbroek (NSO), Héctor Socas-Navarro (IAC), Tom Schad (NSO), Jeffrey Reep (UH), Sanjiv Tiwari (LMSAL), Jiong Qiu (Montana State U.), Kiyoshi Ichimoto (Ritsumeikan U.), Sarah Jaeggli (NSO), Yukio Katsukawa (NAOJ), Ayumi Asai (Kyoto U.), Kevin Reardon (NSO), Alexandra Tritschler (NSO), Friedrich Wöger (NSO), Thomas Rimmele (NSO) |
Abstract:
Magnetic reconnection in the solar atmosphere can release stored magnetic energy efficiently into the solar atmosphere and the heliosphere. In order to explain the high efficiency, various reconnection models have been proposed. Direct measurements of magnetic and electric field structures at or around a reconnection X point where the magnetic fields reconnect would enable us to determine which reconnection models work. Using the newly commissioned National Science Foundation's Daniel K. Inouye Solar Telescope (DKIST), we observed NOAA active region 12995 on February 23rd, 2022, in the Ca II H 397 nm, Fe I 630.15 nm, Fe I 630.25 nm, and Ca II 854 nm lines using the Visible SpectroPolarimeter (ViSP) together with blue continuum imaging with the Visible Broadband Imager (VBI). We successfully obtained Stokes spectra of Ellerman bombs, which are brightenings in the lower chromosphere and are thought to be associated with magnetic reconnection. We applied Departure coefficient aided Stokes Inversion based on Response function (DeSIRe, Ruiz Cobo et al. 2022) to the Stokes spectra of the four lines at the Ellerman bomb. As a result, it is revealed that the inferred line-of-sight component of the magnetic field strongly varies along the line-of-sight, so that It has at least 3 or 4 peaks. Moreover, at the Ellerman bomb, we discovered a broadband circular polarization in a Balmer line of the neutral hydrogen at 397 nm, H epsilon, that can only be explained by the presence of an external electric field. In this presentation, we will discuss the magnetic diffusivity derived from the measured electric field and the electric current.