EGRET All Sky Map
Credit: EGRET Team/NASA/Honeywell Max Q Digital Group, Angela Cheyunski

Mysterious Radiant Sources

Probably the most mysterious way to view the sky is in gamma-rays. Gamma rays are the most energetic form of electromagnetic radiation, and it takes extraordinary processes to generate them. Powerful explosions (like those produced when a star falls into a black hole, or 2 neutron stars collide, or when a matter cloud collides with an anti-matter cloud) can produce gamma rays, but such sources only shine for a brief period, then fade. Some sources emit gamma rays all the time. How these sources do this is not entirely known, though it probably involves very strong magnetic fields or extremely powerful shocks. The EGRET detector on the Compton Gamma Ray Observatory produced the best map of the gamma ray sources in the universe. The image above is the EGRET gamma ray source map, in which the bright areas are the 271 gamma-ray emitting objects seen by EGRET. This map is in Galactic coordinates, which means that the center of the Milky Way is at the center of the image, and the disk of the Galaxy runs along the center of the image, right to left. This false color image shows the brightness of the gamma ray sources seen by EGRET; large white objects glow more brightly in gamma rays than small orange ones.

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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 August 7, 2000