Researchers at the University of Helsinki have succeeded in something that has been pursued since the 1970s: explaining the X-ray radiation from black hole surroundings. The radiation originates from the combined effect of ...
Astronomy
Aug 20, 2024
0
447
Like two Sumo wrestlers squaring off, the closest confirmed pair of supermassive black holes have been observed in tight proximity. These are located approximately 300 light-years apart and were detected using NASA's Hubble ...
Astronomy
Sep 9, 2024
0
241
A new study in Physical Review Letters offers the first detection of the cross-correlation between cosmic shear and diffuse X-ray background, helping to understand the distribution of baryonic matter in the universe.
By using new data from NASA's Chandra X-ray Observatory and Neil Gehrels Swift Observatory as well as ESA's XMM-Newton, a team of researchers has made important headway in understanding how—and when—a supermassive black ...
Astronomy
Aug 14, 2024
0
253
Astronomers from the Pennsylvania State University (PSU) and elsewhere have observed an X-ray binary system known as CXOU J005245.0-722844. They detected an X-ray outburst from this binary and found that it harbors a white ...
Using various space observatories, astronomers have performed X-ray polarimetric and spectral observations of a bright low-mass X-ray binary known as Serpens X-1. Results of the observational campaign, published August 29 ...
Laser-plasma accelerators take up less space than conventional facilities, which are sometimes kilometers long. Such compact particle sources can accelerate electron bunches efficiently, enabling X-ray lasers that fit in ...
Optics & Photonics
Aug 30, 2024
0
70
Researchers at the University of Houston unveiled an advancement in X-ray imaging technology that could provide significant improvements in medical diagnostics, materials and industrial imaging, transportation security and ...
Optics & Photonics
Aug 14, 2024
1
75
Polymers such as polypropylene are fundamental materials in the modern world, found in everything from computers to cars. Because of their ubiquity, it's vital that materials scientists know exactly how each newly developed ...
Polymers
Aug 23, 2024
0
1
Exoplanets are often discovered using the transit method (more than three-quarters of those discovered have been found this way.) The same transit technique can be used to study them, often revealing details about their atmosphere.
Astronomy
Aug 27, 2024
0
39
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.
This text uses material from Wikipedia, licensed under CC BY-SA
