Results 11 to 20 of about 49,075 (253)
Boron abundances in diffuse interstellar clouds [PDF]
Proceedings of the International Astronomical Union, 2009 AbstractWe 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 λ1362 resonance line, with each detection confirmed by the presence of absorption from other dominant ions at the same ...
Ritchey, A. M. +3 more
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Mapping atomic and diffuse interstellar band absorption across the Magellanic Clouds and the Milky Way [PDF]
, 2015 Diffuse interstellar bands (DIBs) trace warm neutral and weakly-ionized diffuse interstellar medium (ISM). Here we present a dedicated, high signal-to-noise spectroscopic study of two of the strongest DIBs, at 5780 and 5797 \AA, in optical spectra of 666
M. Bailey +3 more
semanticscholar +5 more sources
The CN radical in diffuse interstellar clouds
The Astrophysical Journal, 1984 A survey of 15 lines of sight for the CN B /sup 2/..sigma../sup +/--X /sup 2/..sigma../sup +/ interstellar absorption lines shows that the CN column density in diffuse interstellar clouds follows the relation log N(CN)proportionalm log N(H/sub 2/), where mroughly-equal3.
S. R. Federman +2 more
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Unresolved velocity structure in diffuse interstellar clouds
The Astrophysical Journal, 1988 Recent high-resolution observations of interstellar absorption lines of CH and CN toward Zeta Oph obtained by Crane et al. (1986), and Palazzi et al. (1988), exhibit line widths that suggest thermal line broadening at high temperature, T about 1200 K.
Black, J.H., Dishoeck, E.F. van
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On the CH(+) ion in diffuse interstellar clouds
The Astrophysical Journal, 1986 Un balayage de 65 lignes de visee dans la Voie Lactee Sud dans la raie interstellaire de CH + a 4232 A a permis 30 detections. La densite de colonne de CH + N(CH + ) est bien correlee avec H 2 excite par rotation detecte par des balayages effectues avec Copernicus.
D. L. Lambert, A. C. Danks
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Photoionization and photodissociation in diffuse interstellar clouds
The Astrophysical Journal, 1981 An accurate treatment of radiative transfer is used to explore the effects of grain scattering properties on the photoionization and photodissociation efficiencies of atomic and molecular constituents in diffuse clouds and to calculate the rates of heat deposition by photoelectric emission from grains.
W. G. Roberge +2 more
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Calcium abundance variations in diffuse interstellar clouds
The Astrophysical Journal, 1976 Observations are discussed which show that the Na I/H2 column-density ratio is relatively constant among different clouds where H2 is optically thin, but the Na I/Ca II column-density ratio varies. This implies that the gas-phase abundance of calcium is variable. It is proposed that the wide variation in the gas-phase calcium abundance can be explained
M. Jura
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Observations of CO emission from diffuse interstellar clouds
The Astrophysical Journal, 1976 We report measurements of, and upper limits for, millimeter-wavelength CO emission from interstellar clouds which have previously been studied via optical absorption lines. Along with CO measurements made by the Copernicus satellite, the results can be used to place constraints on models for interstellar chemistry.
G. R. Knapp, M. Jura
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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
M. Gerin, H. Liszt
semanticscholar +1 more source
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. and with a 21 cm flux density greater than 1 Jy were observed for about 120 hours.
Dwarakanath, K. S.
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