Investigating the off-axis GRB afterglow scenario for extragalactic fast X-ray transients H. C. I. Wichern, M. E. Ravasio, P. G. Jonker, J. A. Quirola-Vásquez, A. J. Levan, F. E. Bauer and D. A. Kann A&A, 690 (2024) A101 Published online: 02 October 2024 DOI: 10.1051/0004-6361/202450116