Afterglow Gives Clues to Gamma Ray Bursts

Since their discovery in 1967, intense gamma ray bursts in the universe have mystified scientists. Now a group of scientists led by Alberto J. Castro-Tirado of the Instituto de Astrofisica de Andalucia in Spain has presented findings that may explain what happens after the initial event.

Using information obtained from the Italian-Dutch x-ray satellite BeppoSAX, the Compton Gamma-Ray Observatory and other instruments, researchers noticed a complex light curve occurring after the initial burst. The declining curve suggests color dependence that could be related to a cooling break passing the UV optical band one day after the gamma ray burst. Within two days, a collimated jet also appeared. The group presented its findings in a paper published in the March 26 issue of Science.