TESTING GAMMA-RAY BURST JET STRUCTURE WITH THE DISTRIBUTION OF GAMMA-RAY ENERGY RELEASE

We present a general method for testing gamma-ray burst (GRB) jet structure and carry out a comprehensive analysis of the prevalent jet structure models. According to the jet angular energy distribution, we can not only derive the expected distribution of the GRB isotropic-equivalent energy release for any possible jet structure, but also obtain a two-dimensional distribution including redshift z. By using the Kolmogorov-Smirnov test, we compare the predicted distribution with the observed sample and find that the power-law-structured jet model is most consistent with the current sample and that the uniform jet model is also plausible. However, this conclusion is tentative because of the small size and the inhomogeneity of this sample. Future observations (e.g., Swift) will provide a larger and less biased sample for us to make a robust conclusion by using the procedure proposed in this paper.