[P-EM11] Frontiers in solar physics

[PEM11-03] DKISTを用いた太陽電場測定

*阿南 徹¹、Casini Roberto²、Uitenbroek Han¹、Socas-Navarro Héctor³、Schad Tom¹、Reep Jeffrey⁶、Tiwari Sanjiv⁵、Tarr Lucas¹、Qiu Jiong⁹、一本 潔⁴、Jaeggli Sarah ¹、勝川 行雄⁷、浅井 歩⁸、Reardon Kevin¹、Tritschler Alexandra¹、Wöger Friedrich¹、Rimmele Thomas¹ (1.National Solar Observatory、2.High Altitude Observatory、3.Institute de Astrofísica de Canarias、4.立命館大学、5.Lockheed Martin Solar and Astrophysics Laboratory、6.University of Hawai`i at Mānoa、7.国立天文台、8.京都大学、9.Montana State University)

キーワード：太陽物理、電場、彩層、偏光分光、DKIST

Electric fields experienced by atoms play a central role in magnetic diffusion, magnetic energy dissipation, and moreover particle accelerations. Despite their importance, attempts at measuring electric fields in the solar atmosphere are scarce, because it is commonly assumed that electric fields must vanish quickly or only exist at unresolvable spatial scales due to the high electric conductivity. Using the newly commissioned US National Science Foundation's Daniel K. Inouye Solar Telescope (DKIST), we observed NOAA active region 12995 on February 23rd, 2022, in three spectral ranges, i.e., 397 nm, 630 nm, and 854 nm, using the Visible SpectroPolarimeter (ViSP). We successfully obtained Stokes spectra of Ellerman bombs, transient brightenings in the lower chromosphere associated with magnetic reconnection. At the Ellerman bomb, we discovered a broadband circular polarization in a Balmer line of the neutral hydrogen at 397 nm, H epsilon, that is consistent with the presence of an electric field. This discovery provides critical observational evidence of magnetic diffusivity enabling reconnection. In this presentation, we will discuss science objectives that this cutting-edge diagnosis enables us to address.