Results 11 to 20 of about 3,801,891 (296)
OH + IN DIFFUSE MOLECULAR CLOUDS [PDF]
The Astrophysical Journal, 2013 Near ultraviolet observations of OH+ and OH in diffuse molecular clouds reveal a preference for different environments. The dominant absorption feature in OH+ arises from a main component seen in CH+ (that with the highest CH+/CH column density ratio), while OH follows CN absorption.
Porras, A. J. +3 more
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Formation of Dust Filaments in the Diffuse Envelopes of Molecular Clouds [PDF]
The Astrophysical Journal, 2021 Abstract The path to understanding star formation processes begins with the study of the formation of molecular clouds. The outskirts of these clouds are characterized by low column densities that allow the penetration of ultraviolet radiation, resulting in a nonnegligible ionization fraction and the charging of the small dust grains ...
Leire Beitia-Antero +2 more
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Model calculations for diffuse molecular clouds [PDF]
The Astrophysical Journal, 1974 A steady state isobaric cloud model is developed. The pressure, thermal, electrical, and chemical balance equations are solved simultaneously with a simple one dimensional approximation to the equation of radiative transfer appropriate to diffuse clouds.
A. E. Glassgold, W. D. Langer
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Cosmic-ray ionization in diffuse molecular clouds
AIP Conference Proceedings, 2018 Cosmic rays are believed to play an essential role in determining the chemistry and the evolution of molecular clouds. This is because they are usually considered to be the main ionization agent of these star-forming regions. We have recently studied such a hypothesis from a theoretical point of view for the case of diffuse molecular clouds using the ...
V. H. M. Phan, Phan, V.H.M
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THE TRANSITION FROM DIFFUSE ATOMIC CLOUDS TO DENSE MOLECULAR CLOUDS [PDF]
Proceedings of the 73rd International Symposium on Molecular Spectroscopy, 2018 We explore the transition from diffuse to dense molecular gas by combining a variety of tracers for density and composition. Observations and chemical modeling of CH, CH$^{+}\!$, and CN absorption at visible wavelengths from McDonald Observatory and the
Johnathan Rice, Steven Federman
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THE TRANSITION FROM DIFFUSE ATOMIC GAS TO MOLECULAR CLOUD IN TAURUS [PDF]
Proceedings of the 74th International Symposium on Molecular Spectroscopy, 2019 We study four lines of sight that probe the transition from diffuse molecular gas to molecular cloud material in Taurus. Measurements of atomic and molecular absorption are used to infer the distribution of species and the physical conditions in the direction to stars behind the Taurus Molecular Cloud.
Federman, Steven +8 more
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Submillimetre molecular line observations and modelling of molecular clouds. [PDF]
, 1985 PhDSubmillimetre molecular line observations of molecular clouds in our galaxy are presented, and the data analysed using various alternative cloud models.
Richardson, Kevin John
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TRACING TURBULENT AMBIPOLAR DIFFUSION IN MOLECULAR CLOUDS [PDF]
The Astrophysical Journal, 2010 Though flux freezing is a good approximation frequently assumed for molecular clouds, ambipolar diffusion (AD) is inevitable at certain scales. The scale at which AD sets in can be a crucial parameter for turbulence and the star formation process.
Li, Hua-bai +3 more
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An Absorption Survey Of C3h+ And C4h In Diffuse Clouds Toward Galactic Continuum Regions [PDF]
, 2022 Observations of the diffuse interstellar gas over the past few decades have revealed a surprisingly rich molecular inventory comprising over 25\% of all known interstellar molecules.
Gupta, Harshal
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Molecular cloud abundances and anomalous diffusion [PDF]
Astronomische Nachrichten, 2007 AbstractThe chemistry of molecular clouds has been studied for decades, with an increasingly general and sophisticated treatment of the reactions involved. Yet the treatment of turbulent diffusion has remained extremely sketchy, assuming simple Fickian diffusion with a scalar diffusivity D.
Marschalko, G. +2 more
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