EGRET Image of the Blazar 3C279
This EGRET image shows the gamma-ray quasars 3C279 and 3C273. Prior to the launch of the Compton Observatory in June of 1991, the quasar 3C273 was the only extragalactic source of high-energy gamma-rays known. However, when the EGRET instrument viewed this region of the sky, they discovered another quasar, 3C279, to be brighter than 3C273. In fact, 3C279 was one of the brightest high-energy gamma-ray objects in the sky in June 1991. This is all-the-more remarkable considering its tremendous distance of about 4 billion light years. Such bright, flaring gamma-ray emission had never been seen before from active galaxies, and 3C279 became the archetypical member of a new class discovered by EGRET called gamma-ray blazars. We now know that the most violent and interesting blazars are found at gamma-ray energies.
If you have a question about CGRO, please contact us via the Feedback form.