Lyman-alpha radiation

Lyman-alpha radiation

[′lī·mən ′al·fə ‚rād·ē′ā·shən]
(spectroscopy)
Radiation emitted by hydrogen associated with the spectral line in the Lyman series whose wavelength is 121.5 nanometers.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
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[3] The Lyman-alpha radiation that MUSE observed originates from atomic electron transitions in hydrogen atoms which radiate light with a wavelength of around 122 nanometres.
The first ELAN, discovered in 2014, was named the Slug Nebula, and scientists believe that it - as well as most other ELANs detected since then - is emitting Lyman-alpha radiation as a result of being illuminated by intense radiation from quasars.
Using the 10-meter Keck I telescope in Hawaii, the team detected Lyman-alpha radiation emitted by cold hydrogen atoms spotlighted by the quasar's intense ultraviolet beam.
As observed from Earth, the ultraviolet Lyman-alpha radiation is shifted to longer; or redder, wavelengths by the expansion of the universe.
The Lyman-alpha radiation that Hu and her colleagues detected has a redshift of 6.56, the highest ever recorded.
This is hardly surprising, though, since the redshifted Lyman-alpha radiation occurs only fleetingly and brightens the Sun by a minuscule amount.
Lyman-alpha radiation from the new object detected by Hu and McMahon has shifted to a near-infrared wavelength of 918 nm, revealing its extraordinary distance.
One caveat, says Dickinson, is that such studies require highly selective filters, each of which detects Lyman-alpha radiation from galaxies that reside within an extremely narrow range of distances from Earth.