hydrogen line


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hydrogen line

(21 cm line) See H I region.

hydrogen line

[′hī·drə·jən ‚līn]
(spectroscopy)
A spectral line emitted by neutral hydrogen having a frequency of 1420 megahertz and a wavelength of 21 centimeters; radiation from this line is used in radio astronomy to study the amount and velocity of hydrogen in the Galaxy.
References in periodicals archive ?
Under the circumstances, hydrogen line shapes may be providing important clues with respect to the interaction between molecular hydrogen and larger condensed structures in the chromosphere.
A minor objection to the use of Stark broadening to explain the width of the hydrogen lines in the gaseous models rests on the fact that the appropriate experiments on hydrogen plasma do not exist.
Hydrogen lines were known to be extremely broad from the days of Henry Norris Russell and Donald H.
Using the FUNcube Dongle and budget alternatives for hydrogen line reception
In the meantime Laurence Newell has offered to use the Spectracyber hydrogen line receiver purchased for this project with one of his own dishes to provide data for the website.
On the first commissioning flight, EXES observed emissions from Jupiter's atmosphere in two molecular hydrogen lines.
AM CVn stars differ from most other cataclysmic variables (CVs) in the lack of hydrogen lines from their spectra.
A sampling of topics: the microstructure of a sunspot penumbra, penumbral moving magnetic features, SOLIS-VSM solar vector magnetograms, multigrid methods for polarized radiative transfer, tunable narrow-band filter for imaging polarimetry, the diffraction limited spectro-polarimeter, a brief overview of the Second Solar Spectrum, polarizability factors for molecular bands, spectro-polarimetry of cool stars, molecular diagnostics of the internal structure of starspots and sunspots, and the effect of turbulent electric fields on the scattering polarization of hydrogen lines.
Tenders are invited for Supply of lobe valves for hydrogen lines
The ramps were on the tank to protect a cable tray and two pressurization oxygen and hydrogen lines during the dynamic portion of launch, which includes liftoff through about the first three minutes of the climb to orbit.
The hydrogen lines ofthe Balmer series, and, as Babcock has recently shown, ofthe Paschen series as well, are very strong in the Sun, though the energy required to put an atom into condition to absorb these series is, respectively, 10.
Today, the quest to link helium abundances and primordial nucleosynthesis has continued [26-30] using two lines of reasoning: 1) the analysis of anisotropy in the microwave background [132,133] and 2) the observation of helium and hydrogen lines from low-metallicity extragalactic HII regions [26,134-137].