Jet Breaks in Short Gamma-ray Bursts . Ii . the Collimated Afterglow of Grb 051221 A

We report the best evidence to date of a jet break in a short gamma-ray burst (GRB) afterglow, using Chandra and Swift XRT observations of the X-ray afterglow of GRB 051221A. The combined X-ray light curve, which has three breaks, is similar to those commonly observed in Swift observations of long GRBs. A flat segment of the light curve at 0.1 days after… CONTINUE READING