Results 21 to 30 of about 547 (181)
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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Interstellar Bow Shocks around Fast Stars Passing through the Local Interstellar Medium
The Astrophysical Journal, 2023 Bow shocks are produced in the local interstellar medium by the passage of fast stars from the Galactic thin-disk and thick-disk populations with velocities V _* = 40–80 km s ^−1 .
J. Michael Shull, S. R. Kulkarni
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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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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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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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Interstellar processes: Ortho/para conversion, radiative association, and dissociative recombination
EPJ Web of Conferences, 2015 The study of the ortho-to-para ratio of assorted gas-phase interstellar molecules such as H2, H2O, NH3, and H2O+ has gained interest in recent years, based partially on new spectral observations of light hydrides by the Herschel Space Observatory ...
Herbst Eric
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Far-ultraviolet Dust Extinction and Molecular Hydrogen in the Diffuse Milky Way Interstellar Medium
The Astrophysical Journal, 2023 We aim to compare variations in the full-UV dust extinction curve (912–3000 Å), with the H i /H _2 /total H content along diffuse Milky Way sightlines, to investigate possible connections between ISM conditions and dust properties. We combine an existing
Dries Van De Putte +4 more
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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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EXCITATION OF C2IN DIFFUSE INTERSTELLAR CLOUDS
The Astrophysical Journal, 2012 We investigate the effects and the implications of incorporating new collision and radiative rates in modeling the excitation of diatomic carbon molecule. The present results suggest that diffuse and translucent interstellar clouds may present a structure in which regions with different densities and kinetic temperatures overlap along the line of sight,
S. Casu, Cesare Cecchi-Pestellini
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