SIMBAD references

Previous research on Lorentz invariance violation in photons from gamma-ray bursts (GRBs) suggested a scenario where multi-GeV photons could be emitted before lower-energy photons at the GRB source frame. This implies the existence of a new preburst phase in addition to the traditionally identified prompt and afterglow stages observed in earlier studies. In this study, we present direct evidence for this novel preburst phase in GRBs based on recent observations of GRB 221009A. Our analysis leverages data from the Fermi Gamma-ray Burst Monitor and Large Area Telescope detectors of the Fermi Gamma-ray Space Telescope, as well as data from the KM2A detector of the Large High Altitude Air-shower Observatory.