Extended Data Fig. 4: Coincidence between the 909-Hz signal’s detection interval and the transition to high-latitude emission.
From: Evidence for a brief appearance of gamma-ray periodicity after a compact star merger
a, Flux evolution of GRB 230307A based on GECAM data in 98-248 keV band. Blue error bars represent the time-resolved flux estimated from the best-fit spectral models, as detailed in ref. 16, including the corresponding time intervals and 1σ uncertainties. The red curve shows the best-fit smoothly broken power law with the corresponding 1σ error region. b, Evolution of temporal slopes. Blue points indicate the temporal slopes predicted by the ‘curvature effect’, and the red curve represents the slopes derived from the smoothly broken power law fitting in a. The vertical purple band marks the 909-Hz signal’s detection interval, which coincides with the transition point where the ‘curvature effect’ begins to dominate the observed gamma-ray flux.
