Results 1 to 10 of about 1,740 (183)
Diffuse Interstellar Clouds [PDF]
Highlights of Astronomy, 1992 AbstractDiffuse clouds are interstellar objects through which starlight is not greatly extinguished. As a result, many studies rely on ultraviolet and visible measurements. The focus of this review is on spectroscopic work involving atomic and molecular lines. From these measurements, the physical and chemical makeup of the clouds is derived.
David L. Lambert, S. R. Federman
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Inhomogeneity within Local Interstellar Clouds*
The Astronomical Journal, 2022 Abstract Analysis of interstellar absorption lines observed in high-resolution Hubble Space Telescope spectra of nearby stars provides temperatures, turbulent velocities, and kinetic properties of warm interstellar clouds. A new analysis of 97 interstellar-velocity components reveals a wide range of temperatures and turbulent velocities ...
Jeffrey L. Linsky +3 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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Creating a new paradigm for the local interstellar medium–A perspective
Frontiers in Astronomy and Space Sciences, 2023 The interstellar medium close to the Sun called the local ISM (LISM) provides critical insights into physical processes and phenomena in the more distant interstellar medium in our Galaxy without the confusion of many complex structures in the sight ...
Jeffrey L. Linsky, Seth Redfield
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Interstellar hydrocarbons: degradation chemistry in diffuse clouds [PDF]
Monthly Notices of the Royal Astronomical Society, 2022 ABSTRACT Observations of diffuse clouds showed that they contain a number of simple hydrocarbons [e.g. CH, C2H, (l- and c-)C3H2, and C4H] in abundances that may be difficult to understand on the basis of conventional gas-phase chemical models.
Zainab Awad, Serena Viti
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Frontiers in Astronomy and Space Sciences, 2021 Stellar systems are often formed through the collapse of dense molecular clouds which, in turn, return copious amounts of atomic and molecular material to the interstellar medium.
Duncan V. Mifsud +6 more
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Turbulence in Interstellar Clouds [PDF]
International Astronomical Union Colloquium, 1989 Above masses of the order of lOO M⊙, molecular clouds have masses and sizes which scale like those of self-gravitating polytropes bounded by an external pervading pressure. It is unlikely that this scaling is due to mere observational bias. But the physics underlying this behaviour is far from being understood.
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The Astrophysical Journal Letters, 2023 Observations of OH ^+ are used to infer the interstellar cosmic ray ionization rate in diffuse atomic clouds, thereby constraining the propagation of cosmic rays through and the shielding by interstellar clouds, as well as the low energy cosmic ray ...
Ábel Kálosi +14 more
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The Distance to High-velocity Cloud Complex M
The Astrophysical Journal, 2023 λ -21 cm HI4PI survey data are used to study the anomalous-velocity hydrogen gas associated with high-velocity cloud Complex M. These high-sensitivity, high-resolution, high-dynamic-range data show that many of the individual features, including MI, MIIa,
G. L. Verschuur, J. T. Schmelz
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Communications Chemistry, 2022 The detection of glycine in comets is suggestive of a cosmic origin for amino acids on Earth, but the formation of glycine in interstellar media remains poorly understood.
Prasad Ramesh Joshi, Yuan-Pern Lee
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