Minifilament (MF) eruption producing small jets and micro-flares is regarded as an important source for coronal heating and the solar wind transients through studies mostly based on coronal observations in the extreme ultraviolet (EUV) and X-ray wavelengths. In this study, we focus on the chromospheric plasma diagnostics of a tiny minifilament in quiet Sun located at [71'', 450''] on 2021--08--07 at 19:11 UT observed as part of the ninth encounter of the PSP campaign. Main data obtained are the high cadence, high resolution spectroscopy from the Fast Imaging Solar Spectrograph (FISS) and high-resolution magnetograms from the Near InfraRed Imaging Spectropolarimeter (NIRIS) on the 1.6~m Goode Solar Telescope (GST) at Big Bear Solar Observatory (BBSO). The mini-filament with size ∼1''×5'' and a micro-flare are detected in both the Hα line center and SDO/AIA 193, 304~\AA\ images. On the NIRIS magnetogram, we found that the cancellation of a magnetic bipole in the footpoints of the minifilament triggered its eruption in a sigmoidal shape. By inversion of the \ha\ and Ca {\sc ii} spectra under the embedded cloud model, we found a temperature increase of 3,800 K in the brightening region, associated with rising speed average of MF increased by 18~kms−1. This cool plasma is also found in the EUV images. We estimate the kinetic energy change of the rising filament as 1.5×1025~ergs, and thermal energy accumulation in the MF, 1.4×1025~ergs. From the photospheric magnetograms, we find the magnetic energy change is 1.6×1026~ergs across the PIL of converging opposite magnetic elements, which amounts to the energy release in the chromosphere in this smallest two-ribbon flare ever observed.
@article{arxiv.2402.08483,
title = {High Resolution Imaging Spectroscopy of a Tiny Sigmoidal Mini-filament Eruption},
author = {Jiasheng Wang and Jeongwoo Lee and Jongchul Chae and Yan Xu and Wenda Cao and Haimin Wang},
journal= {arXiv preprint arXiv:2402.08483},
year = {2024}
}