Related topics: black holes · radiation · wavelength · protein · laser

Ultra-bright X-ray source awakens near a galaxy not so far away

A new ultra-bright source of X-rays has awakened in between our galactic neighbors the Magellanic Clouds, after a 26-year slumber. This is the second-closest such object known to date, with a brightness greater than a million ...

A new galactic center adventure in virtual reality

By combining data from telescopes with supercomputer simulations and virtual reality (VR), a new visualization allows you to experience 500 years of cosmic evolution around the supermassive black hole at the center of the ...

Astronomers capture a pulsar 'powering up'

A Monash-University-led collaboration has, for the first time, observed the full, 12-day process of material spiraling into a distant neutron star, triggering an X-ray outburst thousands of times brighter than our Sun.

Astronomers find cosmic golden needle buried for two decades

Determined to find a needle in a cosmic haystack, a pair of astronomers time traveled through archives of old data from W. M. Keck Observatory on Mauankea in Hawaii and old X-ray data from NASA's Chandra X-ray Observatory ...

MAXI J1820+070: Black hole outburst caught on video

Astronomers have caught a black hole hurling hot material into space at close to the speed of light. This flare-up was captured in a new movie from NASA's Chandra X-ray Observatory.

Elucidation of nanostructures in practical heterogeneous catalysts

Scientists from Japan Advanced Institute of Science and Technology (JAIST) and University of Torino (UNITO) have cooperatively clarified the nanostructure of the heterogeneous Ziegler-Natta catalyst by means of combined synchrotron ...

Untangling a key step in photosynthetic oxygen production

Photosystem II is a protein complex in plants, algae and cyanobacteria that is responsible for splitting water and producing the oxygen we breathe. Over the past few years, an international collaboration between scientists ...

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X-ray

X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 10 to 0.01 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3 × 1016 Hz to 3 × 1019 Hz) and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays. In many languages, X-radiation is called Röntgen radiation after Wilhelm Conrad Röntgen, who is generally credited as their discoverer, and who had called them X-rays to signify an unknown type of radiation.:1-2

X-rays are primarily used for diagnostic radiography and crystallography. As a result, the term X-ray is metonymically used to refer to a radiographic image produced using this method, in addition to the method itself. X-rays are a form of ionizing radiation and as such can be dangerous.

X-rays from about 0.12 to 12 keV are classified as soft X-rays, and from about 12 to 120 keV as hard X-rays, due to their penetrating abilities.

The distinction between X-rays and gamma rays has changed in recent decades. Originally, the electromagnetic radiation emitted by X-ray tubes had a longer wavelength than the radiation emitted by radioactive nuclei (gamma rays). So older literature distinguished between X- and gamma radiation on the basis of wavelength, with radiation shorter than some arbitrary wavelength, such as 10−11 m, defined as gamma rays. However, as shorter wavelength continuous spectrum "X-ray" sources such as linear accelerators and longer wavelength "gamma ray" emitters were discovered, the wavelength bands largely overlapped. The two types of radiation are now usually defined by their origin: X-rays are emitted by electrons outside the nucleus, while gamma rays are emitted by the nucleus.

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