Results 181 to 190 of about 584,976 (219)
Some of the next articles are maybe not open access.
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 ...
openaire +2 more sources
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 ...
openaire +2 more sources
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 ...
openaire +2 more sources
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 ...
openaire +2 more sources
The Composition of Interstellar Molecular Clouds
Space Science Reviews, 1999We 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.
openaire +3 more sources
Interstellar and Atmospheric Clouds
Nature, 1970WE 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
openaire +1 more source
Molecules in Interstellar Clouds
1981The 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
openaire +1 more source
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
openaire +1 more source
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
openaire +1 more source
Fragmentation of Interstellar Clouds
2014The 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.
openaire +1 more source
Translucent Interstellar Clouds
2011A 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.
openaire +1 more source
The Expansion of an Interstellar Gas-Cloud into a Vaccum*
Monthly Notices of the Royal Astronomical Society, 1950Untersucht wird die eindimensionale Bewegung von H-Atomen aus einer interstellaren Gaswolke in ein Vakuum für die beiden Fälle, daß a) die Gaswolke isotherm ist und daß b) in der Gaswolke ein Temperaturgradient senkrecht zur Grenzfläche der Wolke existiert. Angewendet wird die Riemannsche Lösungsmethode für die Kontinuitäts- und Bewegungsgleichung.
openaire +1 more source
Interstellar objects outnumber Solar system objects in the Oort cloud
Monthly Notices of the Royal Astronomical Society: Letters, 2021Amir Siraj, Abraham Loeb
exaly