Upper: Artists rendition of GRB 020813; lower: Chandra grating spectrum in false color
Credit:Illustration: CXC/M.Weiss; Spectrum: NASA/CXC/N.Butler et al.

Cosmic Chrysanthemum

A growing body of evidence suggests that, when some very massive stars die, they produce unusually bright explosions called gamma-ray bursts (GRBs). As shown in the illustration above, the death of these stars are thought to result in the formation of a black hole at the very center of the star, and as the black hole devours the star, powerful jets of material erupt from the star's core and "evaporate" the rest of the star. The Chandra X-ray Observatory has helped astronomers fill out this picture. The inset shows a false color image taken with Chandra's High Energy Transmission Grating of the "afterglow" of a gamma-ray burst called GRB 020813. This observation lets astronomers determine the composition and speed of the material in the ejecta of the GRB, and show that this ejecta seems to be made up of matter usually produced by extremely massive stars. Also, the speed of the outflow was measured to be about one tenth the speed of light. The Chandra observation also suggests that only a small amount of the material was illuminated by the GRB, consistent with the jet model.

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Page Author: Dr. Michael F. Corcoran
Last modified Friday, 20-Apr-2012 15:28:21 EDT