星系研究组知识库

Based on the standard energy reservoir of gamma-ray burst (GRB) jets and the relationship between the peak energy (E(p)) of the nuF(nu) spectrum and the equivalent isotropic energy (E(iso)), we test the GRB probability distributions as a function of viewing angle (theta) and of viewing angle together with redshift (z), P(theta) and P(theta, z), predicted by the universal structured jet (USJ) model with simulations on observational bases for a detection threshold of S > 4 x 10(-5) erg cm(-2), where S is the total fluence in an energy band >20 keV. We simulate a sample including 10(6) GRBs, and then derive P(theta) and P(theta, z). We show that both simulated and theoretical P(theta) and P(theta, z) are consistent with each other. This consistency seems to be regarded as support for the USJ model. A small difference between the theoretical and simulated results might be due to the observed E(p) distribution used in our simulations, which perhaps suffers a little of biases for E(p) < 100 keV.