Results 271 to 280 of about 42,575 (298)
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Diffuse Atomic and Molecular Clouds
Annual Review of Astronomy and Astrophysics, 2006Diffuse interstellar clouds have long been thought to be relatively devoid of molecules, because of their low densities and high radiation fields. However, in the past ten years or so, a plethora of polyatomic molecules have been observed in diffuse clouds, via their rotational, vibrational, and electronic transitions.
Theodore P. Snow, Benjamin J. McCall
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Cosmic-ray ionization in diffuse molecular clouds
AIP Conference Proceedings, 2018Cosmic 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 ...
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AMBIPOLAR DIFFUSION AND TURBULENT MAGNETIC FIELDS IN MOLECULAR CLOUDS
Modern Physics Letters A, 2011We review the introduction and development of a novel method for the characterization of magnetic fields in star-forming regions. The technique is based on the comparison of spectral line profiles from coexistent neutral and ion molecular species commonly detected in molecular clouds, sites of star formation.
Houde, Martin +3 more
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MHD Shock Waves in Diffuse Molecular Clouds
1987The theory of low-velocity (v s ≤ 30km/s) MHD shock waves in diffuse molecular gas is reviewed. The multifluid nature of the gas dynamics is emphasized, and the important microphysics and chemistry is mentioned. Recent attempts to use shock waves to account for the abundance of interstellar CH+ are discussed, and the required shock frequency and global
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Shocks in Diffuse and Dense Molecular Clouds
1988The chemistry in postshock gas in interstellar clouds is particularly rich because reactions which are endothermic or which have activation barriers proceed more readily in gas heated to T ≳ 103 K than in cooler gas; in particular, the formation of sulfur-bearing and silicon-bearing species is efficient in postshock regions.
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THE TRANSITION FROM DIFFUSE ATOMIC GAS TO MOLECULAR CLOUD IN TAURUS
Proceedings of the 74th International Symposium on Molecular Spectroscopy, 2019We 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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Dense cores associated with diffuse, high-latitude molecular clouds
1989We have identified an unusual class of diffuse, high-latitude molecular clouds (HLC’s) which contain dense ammonia cores. We present preliminary 12CO and NH3 observations of two diffuse, high-latitude clouds, Bernes 48 and MBM 21, which contain dense cores and, in at least one case, an associated IRAS source.
J. G. Stacy, P. C. Myers, H. W. de Vries
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Polar Stratospheric Clouds: Satellite Observations, Processes, and Role in Ozone Depletion
Reviews of Geophysics, 2021Ines Tritscher +2 more
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Impact of aerosols on convective clouds and precipitation
Reviews of Geophysics, 2012Wei-Kuo Tao, Jen-Ping Chen, Zhanqing Li
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