Ultra-fine Observation to Magnetic Reconnection X-flows in the High Chromosphere by Goode Solar Telescope

We carried out high-resolution spectroscopic imaging in Hα and Helium 10830 Å for a set of continuous magnetic reconnections with X-flow plasma motions observed in the high chromosphere, using GST at BBSO on 2021-05-11. The magnetic reconnection current sheet is about 2.2 Mm long and 80–120 km wide in the Hα line center images. Counter-parts of the current sheet and outflows are observed in the DUV slit-jaw image of IRIS and in all EUV wavelengths of SDO/AIA. IRIS/SJI 1400 Å and SDO/AIA 304 Å images present the highest response, which may indicate the reconnection height. The reconnections are triggered recurrently above a bipolar magnetic canceling area. The reconnection zone is heated periodically, and its intensity oscillation power peaks at 4.7 minutes. Outflows detected by the time-distance slide present apparent speeds around 6 km/s. Dark plasma blobs are resolved by Hα line center images within the fine structures of the heated current sheet.