GRB pulse light curve analysis from BATSE

The model successfully fits 86% of Burst and Transient Source Experiment GRB pulses bright enough for structural properties to be measured. Surprisingly, a GRB pulse's light-curve morphology can be accurately predicted by the pulse asymmetry and the stretching/compression needed to align the structural components preceding the temporal mirror with the time- reversed components following it.

Such a prediction is only possible because GRB pulses exhibit temporal symmetry. Time-asymmetric pulses include fast rise exponential decays, rollercoaster pulses, and asymmetric u-pulses, while time-symmetric pulses include u-pulses and crowns. Each morphological type is characterized by specific asymmetries, stretching parameters, durations, and alignments between the smooth and structured components, and a delineation in the asymmetry/stretching distribution suggests that symmetric pulses and asymmetric pulses may belong to separate populations.