We investigate the evolution of the peak energy of nu-f-nu for bright gamma ray bursts observed by the BATSE spectroscopy detectors. We find that the peak energy is correlated with the intensity of the burst, that this energy softens over the burst as a whole and within individual intensity spikes, and that intensity spikes which come late in a burst tend to be softer than earlier spikes within the same burst. We also find evidence that bursts in which the main emission comes well after the triggering event tend to be softer and evolve less than bursts in which the main emission comes promptly after the trigger.
This page is maintained by Lyle Ford ford@cass09.ucsd.edu