Results 191 to 200 of about 36,750 (220)

The Abundance of Interstellar Krypton

The Astrophysical Journal, 1997
We present high signal-to-noise ratio HST Goddard High Resolution Spectrograph (GHRS) observations of the weak interstellar Kr I λ1236 absorption toward the stars τ CMa, κ Ori, e Ori, λ Ori, δ Sco, ω1 Sco, e Per, and ζ Per. In combination with previous GHRS measurements of Kr I in two other sight lines (ζ Oph and 1 Sco), these new observations yield a ...
Jason A. Cardelli, David M. Meyer
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Molecular Abundances in Interstellar Clouds

Physica Scripta, 1985
A brief historical overview is given of the development of our understanding of the abundances of interstellar molecules. The events leading to the detections of interstellar molecules at optical and radio wavelengths are described and a summary is given of the main chemical processes believed to be responsible for molecule formation in interstellar ...
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Abundances in the interstellar medium

The Astronomy and Astrophysics Review, 1992
Recent developments in the theory of element production and the chemical evolution of the galaxy are presented. Following this, observational data and their interpretation are given. A case by case analysis of results for D, He, Li and CNO isotope data in the disk and center of our galaxy is presented; previous results for element gradients are also ...
T. L. Wilson, F. Matteucci
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Chemical abundances in cold, dark interstellar clouds

Icarus, 1991
The Sun may well have formed in the type of interstellar cloud currently referred to as a cold, dark cloud. We present current tabulations of the totality of known interstellar molecules and of the subset which have been identified in cold clouds. Molecular abundances are given for two such clouds which show interesting chemical differences in spite ...
Irvine, William M., Ohishi, M, Kaifu, N
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Abundances in Interstellar Gas

1999
The atomic character, physical conditions, and transparency of diffuse interstellar clouds provide an ideal laboratory to measure gas-phase ISM elemental abundances through absorption-line studies of background stars. Recent ultraviolet observations of diffuse clouds with the Goddard High Resolution Spectrograph (GHRS) onboard the Hubble Space ...
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The Abundance of Interstellar CO

1987
The current understanding of the abundance of CO in interstellar clouds is reviewed from both observational and theoretical points of view. In special circumstances, the CO and H2 column densities can be measured directly by ultraviolet and infrared absorption line techniques.
Ewine F. Dishoeck, John H. Black
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Interstellar Abundances in External Galaxies

1977
This field has been excellently reviewed recently by Peimbert (1975), Burbidge and Burbidge (1975) and Searle (1975). The present discussion will cover work since these and in particular the evidence for composition gradients across galaxies and the systematics with galactic type.
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Abundance Determinations for Interstellar Gas

1980
The results of general abundance studies, using the Copernicus satellite are reviewed. The general pattern of depletion of some elements such as Si, Al, Mn, Fe, and Mg, near the Sun is described. Techniques for obtaining abundances for various species are discussed, as are the aspects of the analysis which are uncertain.
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Isotopic Abundances in Interstellar Clouds

1977
The observation of microwave spectra of molecules in interstellar clouds allows separation and detection of the lines of isotopes of many of the more common elements. Comparison of intensities of isotopic lines shows that the relative isotopic abundances for C, O, S, N, and Si are generally rather similar to those found on Earth.
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Large metallicity variations in the Galactic interstellar medium

Nature, 2021
Annalisa De Cia, Edward B Jenkins, Andrew Fox   +2 more
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