X-ray background

This emission forms 12% 5% of the diffuse X-ray background radiation.

In addition to discrete sources which stand out against the sky, there is good evidence for a diffuse X-ray background.

The dark side of the Moon's disk shadows this X-ray background radiation coming from the deep space.

The newly described X-ray background was observed for almost 28 hours last month through use of the spacecraft's imaging spectrometer.

The company did not have a medical or X-ray background and was conditioned by three previous failures to exploit the medical systems market.

His current areas of research include galaxy clusters, active galactic nuclei, strong gravity, black holes and the X-ray background.

Such so-called seed electrons can be created by ionization by cosmic x-ray background.

Of this background, 6 counts/s comes from the diffuse cosmic X-ray background, with the rest being instrumental.

See cosmic infrared background and X-ray background.

A combination of many unresolved X-ray sources is thought to produce the observed X-ray background.

The diffuse X-ray background (XRB) has also been studied in the area.

The galactic X-ray background is produced largely by emission from hot gas in the Local Bubble within 100 parsecs of the Sun.

The early high-energy end of the spectrum for this diffuse X-ray background was obtained by instruments on board Ranger 3 and Ranger 5.

Analysis of the data from the S150 experiment provided strong evidence that the soft X-ray background cannot be explained as the cumulative effect of many unresolved point sources.

In addition, ASCA's suite of instruments provided the best opportunity at the time for identifying the sources whose combined emission makes up the cosmic X-ray background.

During more than a decade of observations of X-ray emission from the Sun, evidence of the existence of an isotropic X-ray background flux was obtained in 1956.

The Diffuse X-ray Spectrometer (DXS) STS-54 package was flown as an attached payload in January, 1993 to obtain spectra of the diffuse soft X-ray background.

By comparing the soft X-ray background with the distribution of neutral hydrogen, it is generally agreed that within the Milky Way disk, super soft X-rays are absorbed by this neutral hydrogen.

Through the course of these investigations, the X-ray background was determined to originated from the central supermassive black holes of distant galaxies, and a better characterization of Type-II Quasars was obtained.

"We can use clouds like the Draco as a yardstick to figure out where the soft X-ray background regions are," said Jeffrey A. Mendenhall, a graduate student who worked on the project at Penn State.

It was intended primarily to observe the Sun, which it did very well during its 2 year lifetime, but it also detected a flaring episode from the source Sco X-1 and measured the diffuse cosmic X-ray background.

OSO-3 obtained extensive observations of solar flares, the cosmic diffuse X-ray background, and the observation of a single flare episode from Scorpius X-1, the first observation of an extrasolar X-ray source by an observatory satellite.

Discussing the implications of the findings at a news conference, Dr. Trimble said the objects showed for the first time what is creating the X-ray background in space and also revealed that this background radiation is not perfectly smooth but instead marked by subtle fluctuations.

In 1993, theoretical cosmologist Jim Peebles criticized the cosmology of Klein (1971) and Alfvén's 1966 book, Worlds-Antiworlds, writing that "there is no way that the results can be consistent with the isotropy of the cosmic microwave background radiation and X-ray backgrounds".

The X-ray background radiation that reaches Earth from all directions of the sky was the focus of a study by astrophysicists at Johns Hopkins University in Baltimore and the Copernicus Astronomical Center in Warsaw, Poland, who have published their findings in the current issue of The Astrophysical Journal.