NASA's High Energy Astrophysics Observatory-1 measured the `cosmic low-energy background` in the late 1970s. The X-rays and gamma ray radiation is thought to come from very distant, supermassive black holes.
Now new results from Europe's Integral gamma-ray observatory have confirmed that high-energy radiation is 20% more abundant, bringing it into line with what theoreticians predicted. The Earth-orbiting space observatory which normally points out into space, rotated around in January and February 2006 to observe the Earth. As the Earth shielded the satellite from the high-energy background radiation, scientists were able to calibrate the instruments and derive the new results.
"Preliminary analysis indicates we see around 20% more radiation, which is very interesting" - Arvind Parmar, Integral mission manager.
ESA’s XMM-Newton satellite and NASA’s Chandra X-ray Observatory have already confirmed that individual sources are responsible for about 80% of the X-ray background at low energies.
The European astronomical satellite, INTEGRAL, (INTErnational Gamma-Ray Astrophysics Laboratory) is an astronomical satellite for observing the gamma-ray sky. It was selected by the science program committee of the European Space Agency (ESA) on June 3rd, 1993 as a medium size mission. The INTEGRAL satellite was launched on October 17, 2002 by a Russian PROTON launcher.