Program: GN-2024B-FT-112

Fast X-ray Transients (FXTs) manifest as short flashes of X-ray photons (~0.3-10 keV) with durations ranging from minutes to hours. Even though their first discovery was more than two decades ago, their origin is still in mystery. Proposed scenarios for FXTs involve the tidal disruption of a white dwarf by an intermediate-mass black hole, a binary neutron star merger, supernovae shock break-out, and off-axis and/or high-redshift gamma-ray bursts. Unfortunately, progress has been slow as the timescale between the start of the FXT and the announcement of its discovery has been long, which explains the lack of multi-wavelength counterparts associated with FXTs. The successful launch of the X-ray survey satellite Einstein Probe (EP) in January 2024 has started to revolutionize this field by enabling the discovery and immediate follow-up of FXTs. Indeed, during the last months, 89 FXTs have been detected and followed up using optical and near-infrared (NIR) telescopes. Taking advantage of the quickly announced detections of EP, it is necessary to follow up FXTs' fields to catch potential optical and NIR counterparts to disentangle their origins. In that way, Gemini-North and South and their unique instruments have played an important role in observing, characterizing, and classifying FXTs multi-wavelength counterparts. In this proposal, we request GMOS, GNIRS, and FLAMINGOS2 instruments to follow up (in imaging and spectroscopy mode) and characterize the counterparts of FXTs detected by EP.