Results 21 to 30 of about 476,181 (204)
Turbulence in the interstellar medium [PDF]
, 2014 Turbulence is ubiquitous in the insterstellar medium and plays a major role in several processes such as the formation of dense structures and stars, the stability of molecular clouds, the amplification of magnetic fields, and the re-acceleration and ...
Chian, A. C. -L. +9 more
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Chlorine Chemistry in Diffuse Interstellar Clouds [PDF]
Symposium - International Astronomical Union, 1980 The results of recent observations of the column densities of chlorine species in diffuse interstellar clouds are inconsistent with the column densities predicted by model calculations. The use of new atomic and molecular data fails to decrease the discrepancy.
John H. Black, Peter L. Smith
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CO+ as a probe of the origin of CO in diffuse interstellar clouds [PDF]
Astronomy & Astrophysics, 2021 Context. The chemistry of the diffuse interstellar medium is driven by the combined influences of cosmic rays, ultraviolet (UV) radiation, and turbulence. Previously detected at the outer edges of photodissociation regions and formed from the reaction of C+ and OH, CO+ is the main chemical precursor of HCO+ and CO in a thermal, cosmic-ray, and UV ...
Gérin, Maryvonne, Liszt, Harvey
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Electronic spectroscopy of cold cations in a 22-pole trap by indirect methods [PDF]
, 2013 The confining capabilities of a 22-pole ion trap have been employed to mea- sure electronic spectra of cations of astrophysical relevance. The ion trap sits on the head of a closed cycle cryostat, enabling collisional cooling of the confined ions with
Chakrabarty, Satrajit
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The Smallest Sizes of Diffuse Interstellar Clouds [PDF]
International Astronomical Union Colloquium, 1984 AbstractBy observing the difference in optical depths between absorption spectra toward the two components of double sources we have measured the variations in opacity over lengths of less than 0.1 up to 10 pc inside diffuse interstellar clouds. Significant variations are detected on scales larger than about 0.2 pc, but not less. This may represent the
John M. Dickey, J. Crovisier, I. Kazes
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Abundances in Diffuse Interstellar Clouds [PDF]
Highlights of Astronomy, 1980 Interstellar clouds are concentrations of cold (T ≲ 100 K) neutral gas (cf. Spitzer 1978) which are immersed within an intercloud medium. It is worthwhile to distinguish between diffuse clouds (roughly those with E[B-V] ≳ 0.5) and dark clouds (those with E[B-V] ≳ 0.5). This distinction is useful in the sense that diffuse clouds are relatively warm (T ∼
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Observations of Multiphase, High-velocity, Shocked Gas in the Vela Supernova Remnant
The Astrophysical Journal, 2023 We present an analysis of high-resolution far-UV archival spectra obtained with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope of the star HD 75309, which probes high-velocity shocked gas in the Vela supernova remnant (SNR).
Adam M. Ritchey
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Shocks and Molecules in Diffuse Interstellar Cloud Pairs [PDF]
The Astrophysical Journal, 2021 Abstract The diffuse interstellar medium (ISM) is dynamic, and its chemistry and evolution are determined by shock fronts as well as photodissociation. Shocks are implied by the supersonic motions and velocity dispersion, often statistically called “turbulence”.
William T. Reach, Carl Heiles
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INVESTIGATION OF DIFFUSE INTERSTELLAR BANDS OF ORGANIC MOLECULES IN THE SPECTRA OF CEPHEID STARS
Odessa Astronomical Publications, 2016 We describe an effective method of investigation of the Diffuse Interstellar Bands (DIBs) in the spectra of Cepheid stars. DIBs are believed to originate from the absorption of such carriers as polycyclic aromatic hydrocarbons in the interstellar gaseous
S. V. Kashuba +5 more
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Diffuse interstellar clouds associated with dark clouds
The Astrophysical Journal, 1982 Measurements of CH emission at 9 cm toward the bright stars ..cap alpha.. Cam and kappa Cas and from dark clouds near the stars reveal an association between diffuse clouds and dark clouds. Here the term diffuse clouds refers to clouds seen in optical absorption; the term dark clouds refers to opaque regions on the Palomar Sky Survey observed through ...
S. R. Federman, R. F. Willson
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