X-ray sources

X-ray sources

Luminous sources of X-ray emission lying well beyond the Solar System. More than 120 000 are now known, the majority from the ROSAT all-sky survey and deep pointing observations. Optical counterparts include a wide range of astronomical objects, from high-redshift quasars to nearby stars, and even comets. The brightest sources lie in our Galaxy and are identified principally as X-ray binaries (e.g. Scorpius X-1, Cygnus X-1, Cygnus X-3, Centaurus X-3, Hercules X-1), many having an X-ray power 100 to 1000 times the power of the Sun. A smaller subset of bright galactic X-ray sources are identified with young supernova remnants, such as the Crab nebula and the remnant of Tycho's star. Fainter but intrinsically much more powerful X-ray emission is detected from many extragalactic objects, especially rich clusters of galaxies and active galaxies – such as Seyfert galaxies, quasars, and powerful radio galaxies, including Virgo A (M87) and Centaurus A.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006
References in periodicals archive ?
Micro-X, a provider of cold-cathode x-ray technology has announced a multi-faceted collaboration with Thales to develop X-ray imaging systems based on X-ray sources that use Carbon NanoTubes (CNT) cathodes, the company said.
By doing so, NICER is able to track and target cosmic or X-ray sources as the ISS orbits Earth.
Hailey and his team acknowledge that as many as half of their X-ray sources could be rotation-powered millisecond pulsars: fast-spinning neutrons stars that exhibit fewer outbursts.
In 1979, the first multiple-source CT system for dynamic objects was designed at the Mayo Clinic [9], consisting of a large number of X-ray sources and fluorescent screens.
Modern Diagnostic X-Ray Sources: Technology, Manufacturing, Reliability
Most of the X-ray sources are X-ray binaries (XRBs).
Nikon Metrology X-ray sources are at the heart of their X-ray and CT technology, and have been designed and manufactured in-house.
All compact X-ray sources are based on electron impact technology, which involves generating an electron beam by heating a cathode in a strong electric field.
The Einstein observatory was launched in November 1978, It provided high-resolution images and accurate locations for thousands of X-ray sources (Harris et al., 1993).
Users have a choice of X-ray sources, which includes a 3-kW sealed tube, MicroMax-002+ microfocus seal tube, and 1.2-kW MicroMax-007 HF microfocus rotating anode generator.
Many of the pointlike X-ray sources are small, stellar-mass black holes that feed off normal companion stars, Gregory sivakoff of the Ohio State University in Columbus and his colleagues reported last week in Austin, Texas, at a meeting of the American Astronomical Society.