Acceleration and capture of charged particles by the gravitational field of a star, black hole, or galaxy is a source of energetic cosmic X rays.
Cosmic X-ray background, X-ray radiation pervading the universe.
It was followed during the late 1970s by two High-Energy Astronomy Observatories (HEAOs), which explored cosmic X-ray sources.
In addition to discovering the first cosmic X-ray source, Scorpius X-1, astronomers were also puzzled by a uniform glow of X-rays with energies greater than 1.5 keV (1 keV = 1,000 electron volts) coming from all directions.
A number of globular clusters are sources of cosmic X-rays.
As the neutrino astronomers were going underground, Dr. Giacconi, who was born in Genoa, Italy, was going into space in search of cosmic X-rays.
The remainder of the prize goes to Riccardo Giacconi, an Italian now working in the United States, for his work with cosmic X-rays, the invisible wavelengths of light that have revealed secrets otherwise hidden from earthly view.
Discovery of such a low flux and highly absorbed X-ray source could have a significant impact on the origin of the cosmic X-ray background.
These components contribute to bright Cosmic X-ray background (CXB), which can often dominate X-ray emission from the target in the collimator-type instruments when their FoV is exposed to the background sky.
Collimator instruments become useless beyond a certain distance due to high cosmic X-ray background, whereas focusing optics can extend the useful observing condition to a much wider range of orbit profiles, allowing a flexible mission design.
It also implies that if the Cosmic X-ray Background is made up of heavily absorbed sources, they are unlikely to have the absorber confined to a geometrically thin disk as inferred for NGC 4945.
