GRB 011211 X-ray Spectrum
Credit: Reeves et al., Nature 416, 512-515 (4 April 2002)

Post-mortem of a Monster's Death

Gamma ray bursts are the most powerful explosions ever seen in the Universe. The cause of these explosions is controversial, and 2 models have been put forth. One theory suggests that gamma ray bursts are produced by the mergers of 2 neutron stars. The other suggests that gamma ray bursts are produced by an extremely powerful supernova explosion of a stellar monster (a star many times more massive than the sun) after the star uses up its nuclear fuel. A recent observation by the XMM-Newton satellite of a gamma ray burst known as GRB011211 provides crucial clues to resolve this controversy. These clues are contained in the X-ray spectrum (shown above) of the burst's afterglow. For the first time the XMM-Newton spectrum shows the presence of chemical elements like magnesium, silicon and sulfur in the afterglow. These elements are thought to have been produced during the final stages in the evolution of a massive star just prior to the supernova explosion. In addition, scientists measured the speed of this material and found it moving at 10% of the speed of light. The "neutron-star" merger hypothesis could not explain the amount of material seen in the XMM-Newton spectrum.

Last Week * HEA Dictionary * Archive * Search HEAPOW * Education

Each week the HEASARC brings you new, exciting and beautiful images from X-ray and Gamma ray astronomy. Check back each week and be sure to check out the HEAPOW archive!

Page Author: Dr. Michael F. Corcoran
Last modified April 8, 2002