Test for Cosmological Time Dilation in Long Gamma-Ray Bursts

摘要

We present a test to investigate cosmological time dilation in long gamma-ray bursts (t_90 > 1.5 s) using V, the ratio of expected peak counts in 64 and in 1024 ms. The theoretical evolution of V with redshift shows that dimmer bursts have flatter peaks than brighter ones when we assume that (1) the bursters are at cosmological distances, (2) the bursts have standard exponential profiles, and (3) the burst peak duration follows a power law in narrowing with cosmological redshift energy.