A fast-filament eruption observed in the Hα spectral line - I. Imaging spectroscopy diagnosticDenis P. Cabezas, Kiyoshi Ichimoto, Ayumi Asai, Satoru UeNo, Satoshi Morita, Ken-ichi Otsuji and Kazunari ShibataA&A, 690 (2024) A172DOI: https://doi.org/10.1051/0004-6361/202450099