Lyman continuum
(LyC, Ly continuum)
(absorption continuum beginning at Lyman limit)
The Lyman continuum is a spectral feature
due to absorption of photons by neutral atomic hydrogen: a reduced continuum
in the spectrum for photon energies above the Lyman limit,
reduced from the corresponding continuum of a black-body spectrum.
Photons with energies above this limit (Lyman continuum photons,
i.e., those with photon energy values above 13.6 eV)
can be absorbed by any neutral hydrogen atoms
(which ionizes them), thus fewer of such photons proceed.
At the limit is a Lyman jump (aka Lyman break) spectral
feature: a distinct drop in the spectral energy distribution (SED).
The absorption reduces the strength of the most energetic
ultraviolet as well as X-rays and gamma rays.
Early-type stars display the Lyman jump but the feature
cannot be observed from the ground because its not within an
atmospheric window.
However, ground observations of distant, redshifted galaxies
sense it and extremely distant galaxies with the feature are detected
through the dropouts that result (Lyman-break galaxies).
Galaxies from which Lyman continuum photons emerge, i.e., such
absorption is avoided (Lyman continuum escape, LyC escape) are
of research interest. Distant galaxies from which this occurred
have been called Lyman continuum leakers (LyC leakers).
(Lyman,hydrogen,spectral feature)
Further reading:
https://en.wikipedia.org/wiki/Lyman_continuum_photons
https://en.wikipedia.org/wiki/Lyman_series
https://en.wikipedia.org/wiki/Lyman_limit
https://ui.adsabs.harvard.edu/abs/2019ApJ...878...87F/abstract
https://ui.adsabs.harvard.edu/abs/2024ApJ...972..138M/abstract
http://dictionary.obspm.fr/index.php?showAll=1&formSearchTextfield=Lyman+continuum
WaveL | Freq | Photon Energy | | |
0nm | inf | inf | begin | Lyman continuum |
91.18nm | 3.3PHz | 14eV | end | Lyman continuum |
|
Referenced by pages:
continuum
Lyman series (L)
Index