Multiwavelength modelling of the luminous fast blue optical transient AT2024wpp

ABSTRACT Luminous fast blue optical transients (LFBOTs) are a growing class of enigmatic energetic transients. They show fast rises and declines, high temperatures throughout their evolution, and non-thermal emission in radio and X-rays. Their power source is currently unknown, but proposed models include engine-driven supernovae, interaction-powered supernovae, shock cooling emission, intermediate mass black hole tidal disruption events (IMBH TDEs), and Wolf–Rayet/black hole mergers, among others. AT2024wpp is the most optically luminous LFBOT to date and has been observed extensively at multiple wavelengths, including radio, optical, UV, and X-rays. We take models from multiple scenarios and fit them to the AT2024wpp optical, radio, and X-ray light curves to determine which of these scenarios can best describe all aspects of the data. We show that none of the multiwavelength light-curve models can reasonably explain the data, and that other physical arguments disfavour models with homologously expanding ejecta. We discuss how a stellar mass/IMBH TDE of a low-mass star can be tested with late-time observations, and what other scenarios could possibly explain the broad-band data.