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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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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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Origin of CH+ in diffuse molecular clouds [PDF]
Astronomy & Astrophysics, 2017 Context. Molecular clouds are known to be magnetised and to display a turbulent and complex structure where warm and cold phases are interwoven. The turbulent motions within molecular clouds transport molecules, and the presence of magnetic fields induces a relative velocity between neutrals and ions known as the ion-neutral drift (vd).
Valdivia, Valeska +5 more
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Absorption-line Observations of and CO in Sight Lines Toward the Vela and W28 Supernova Remnants
The Astrophysical Journal, 2023 Supernova remnants act as particle accelerators, providing the cosmic-ray protons that permeate the interstellar medium and initiate the ion–molecule reactions that drive interstellar chemistry. Enhanced fluxes of cosmic-ray protons in close proximity to
Nick Indriolo
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The CH+abundance in turbulent, diffuse molecular clouds [PDF]
Monthly Notices of the Royal Astronomical Society, 2015 The intermittent dissipation of interstellar turbulence is an important energy source in the diffuse ISM. Though on average smaller than the heating rates due to cosmic rays and the photoelectric effect on dust grains, the turbulent cascade can channel large amounts of energy into a relatively small fraction of the gas that consequently undergoes ...
Myers, Andrew +2 more
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A Search for OH 18 cm Emission from Intermediate-velocity Gas at High Galactic Latitudes
The Astrophysical Journal, 2023 We present search results of 22 high-latitude (∣ b ∣ > 25°) sightlines for OH 18 cm emission using the 305 m radio telescope at the Arecibo Observatory. These sightlines appear in neutral hydrogen emission at intermediate velocities −90 ≤ V _LSR ≤ −20 km
Allison J. Smith, D. Anish Roshi
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Magnetic Fields in Diffuse HI and Molecular Clouds [PDF]
, 2005 50 pages, 14 figures, to be published as book chapter in 'Cosmic Magnetic Fields'
Heiles, Carl, Crutcher, Richard
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The Transition from Diffuse Molecular Gas to Molecular Cloud Material in Taurus [PDF]
The Astrophysical Journal, 2021 Abstract 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 toward stars behind the Taurus Molecular Cloud (TMC).
S. R. Federman +8 more
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Diffuse molecular clouds at high galactic latitude [PDF]
Symposium - International Astronomical Union, 1991 The IRAS 60 and 100 μ m flux from cirrus clouds are commonly explained by dust continuum emission. But this explanation in some cases requires unexpectedly high dust temperatures. We argue that the contribution of fine structure ...
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Abundance Ratios of OH/CO and HCO+/CO as Probes of the Cosmic-Ray Ionization Rate in Diffuse Clouds
The Astrophysical Journal, 2023 The cosmic-ray ionization rate (CRIR, ζ _2 ) is one of the key parameters controlling the formation and destruction of various molecules in molecular clouds. However, the current most commonly used CRIR tracers, such as ${{\rm{H}}}_{3}^{+}$ , OH ^+ , and
Gan Luo +8 more
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