The observed X-ray background is thought to result from, at the "soft" end (below 0.3 keV), galactic
X-ray emission, the "galactic" X-ray background, and, at the "hard" end (above 0.3keV), from a combination of many unresolved
X-ray sources outside of the
Milky Way, the "cosmic" X-ray background (CXB).
The galactic X-ray background is produced largely by emission from hot gas in the
Local Bubble within 100
parsecs of the
Sun.
Deep surveys with X-ray telescopes, such as the
Chandra X-ray Observatory, have demonstrated that around 80% of the cosmic X-ray background is due to resolved extra-galactic X-ray sources, the bulk of which are unobscured ("type-1") and obscured ("type-2")
active galactic nuclei (AGN).
References
*T Shanks, I Georgantopoulos, GC Stewart, KA Pounds,
The origin of the cosmic X-ray background, ''Nature'' 353, 315 - 320 (26 September 1991);
*Xavier Barcons,
The X-ray Background', 1992 Cambridge University Press, 324 pages {{ISBN, 0-521-41651-5
* Audio Cain/Gay (2009
Astronomy CastX-ray Astronomy
See also
*
X-ray astronomy
*
Wilkinson Microwave Anisotropy Probe
The Wilkinson Microwave Anisotropy Probe (WMAP), originally known as the Microwave Anisotropy Probe (MAP and Explorer 80), was a NASA spacecraft operating from 2001 to 2010 which measured temperature differences across the sky in the cosmic mic ...
*
S150 Galactic X-Ray Mapping
Skylab 3 (also SL-3 and SLM-2) was the second crewed mission to the first American space station, Skylab. The mission began on July 28, 1973, with the launch of NASA astronauts Alan Bean, Owen Garriott, and Jack Lousma in the Apollo command an ...
X-ray astronomy
*X-ray background
Observational astronomy
Cosmic background radiation