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Translucent Interstellar Clouds [PDF]

open access: possible, 2011
A translucent interstellar cloud is one that has visual extinction intermediate between that of a ▶ diffuse cloud and that of a dense ▶molecular cloud. Despite the importance of photochemical processes over much of their extent, translucent clouds contain significant molecular column densities.
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Masses of interstellar clouds

Astrophysics and Space Science, 1978
Equilibrium masses of slowly rotating interstellar gas clouds have been calculated using an equation of state for the interstellar gas developed by Penston and Brown. The rotation is found to increase the equilibrium masses, but still the cloud masses are not as large as indicated by other considerations.
A. N. Dharmani, V. B. Bhatia
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Interstellar Dust Clouds

Nature, 1971
THE failure, thus far, to detect gaseous emission lines from circumstellar dust clouds1–3 and from Bok globules2 raises the possibility that such clouds consist solely of dust grains. The possibility has previously been largely discounted on the grounds that relative diffusion of the grains and gas is slow and inefficient requiring time scales which ...
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Interstellar Molecular Clouds

Science, 1986
The interstellar medium in our galaxy contains matter in a variety of states ranging from hot plasma to cold and dusty molecular gas. The molecular phase consists of giant clouds, which are the largest gravitationally bound objects in the galaxy, the primary reservoir of material for the ongoing birth of new stars, and the medium regulating the ...
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Molecules in Interstellar Clouds

1981
The physical and chemical state of interstellar clouds is reviewed, including recent investigations at the Onsala Space Observatory. The Orion A region is chosen as an example of a “giant” molecular cloud and hence a formation site for massive stars. The Taurus Molecular Clouds, in contrast, may be the future birthplace of solar-type stars.
Irvine, William M.   +2 more
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Interstellar and Atmospheric Clouds

Nature, 1970
WE wish to draw attention to a novel and striking similarity between the physics of two apparently quite disparate situations—the behaviour of the interstellar medium and of water vapour in an atmospheric cloud.
G. R. Evans, M. V. Penston
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Interstellar Molecules and Dense Clouds

Science, 1971
Current knowledge of the interstellar medium is discussed on the basis of recent published studies. The subjects considered include optical identification of interstellar molecules, radio molecular lines, interstellar clouds, isotopic abundances, formation and disappearance of interstellar molecules, and interstellar probing techniques.
D. M. Rank   +2 more
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Fragmentation of Interstellar Clouds

2014
The dense cores that form stars through gravitational collapse are embedded in much larger and more rarefied expanses of gas. How the parent▶molecular cloud produces its substructure of dense cores is the problem of fragmentation. The traditional view is that the parent cloud breaks apart as it collapses in on itself.
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The Composition of Interstellar Molecular Clouds

1999
We consider four aspects of interstellar chemistry for comparison with comets: molecular abundances in general, relative abundances of isomers (specifically, HCN and HNC), ortho/para ratios for molecules, and isotopic fractionation, particularly for the ratio hydrogen/deuterium.
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FRACTAL ASPECTS OF INTERSTELLAR CLOUDS

Fractals, 1993
Interstellar matter consisting of gas and dust shows structures which appear to have self-similar projected shapes, similar to the properties of terrestrial clouds. Moreover, the completely different physics in these interstellar clouds reveals several additional self-similar/fractal aspects which are investigated by extensive astronomical ...
Jürgen Stutzki, Tom Zimmermann
openaire   +3 more sources

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