Results 1 to 10 of about 25,001 (219)
Boron Abundances in Diffuse Interstellar Clouds [PDF]
Proceedings of the International Astronomical Union, 2009 We present a comprehensive survey of B abundances in diffuse interstellar clouds from HST/STIS observations along 56 Galactic sight lines. Our sample is the result of a complete search of archival STIS data for the B II resonance line at 1362 angstroms ...
Adam M. Ritchey +5 more
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Laboratory infrared spectra and fragmentation chemistry of sulfur allotropes [PDF]
Nature CommunicationsSulfur is one of six life-essential elements, but its path from interstellar clouds to planets and their atmospheres is not well known. Astronomical observations in dense clouds have so far been able to trace only 1 percent of cosmic sulfur, in the form ...
Piero Ferrari +4 more
doaj +2 more sources
Kinematics of Diffuse Interstellar Clouds :Recent GMRT Results
, 2004 A high latitude HI 21 cm-line absorption survey toward extragalactic sources was recently completed using the Giant Meterwave Radio Telescope (GMRT). A total of 104 sources with mod(b) > 15 deg.
Dwarakanath, K. S.
core +3 more sources
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
openaire +4 more sources
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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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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The contribution of unresolved sources on the gamma-ray spectrum of molecular clouds [PDF]
EPJ Web of Conferences, 2023 Fermi-LAT observations of the large-scale diffuse gamma-ray emission unveiled that in some locations, towards the inner Galaxy, the spectrum of this component is harder than the local one, measured at the Earth position. If this signal is associated with
Vecchiotti Vittoria +3 more
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Diffuse interstellar band formation in dense clouds [PDF]
Astrophysics and Space Science, 1974 Measurements of the strengths of the diffuse interstellar bands at 4430, 5780 and 5797 A show that the bands tend to be weak with respect to extinction in dense interstellar clouds. Data on 10 stars in the Q Ophiuchi cloud complex show further that the diffuse band-producing efficiency of the grains decreases systematically with increasing grain size ...
Snow, Theodore P., Jr., Cohen, Judith G.
openaire +5 more sources
Molecular Hydrogen and its Proxies HCO+ and CO in the Diffuse Interstellar Medium
The Astrophysical Journal, 2023 There is a robust polyatomic chemistry in diffuse, partially molecular interstellar gas that is readily accessible in absorption at radio/millimeter/submillimeter wavelengths.
Harvey Liszt, Maryvonne Gerin
doaj +1 more source
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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