Results 101 to 110 of about 25,001 (219)

The formation of molecules in diffuse interstellar clouds

The Astrophysical Journal, 1977
A chemical system involving carbon and hydrogen is used to obtain steady-state abundances of a number of molecules over a wide range of densities. The calculated CH abundance agrees well with the astronomical observations. For reasonable values of the rate coefficients, the present system of reactions cannot explain, simultaneously, the measured ...
G. F. Mitchell, P. J. Kuntz, J. L. Ginsburg   +2 more
openaire   +1 more source

Lactea: Web‐Based Spectrum‐Preserving Multi‐Resolution Visualization of the GAIA Star Catalog

Computer Graphics Forum, Volume 44, Issue 3, June 2025.
Abstract The explosion of data in astronomy has resulted in an era of unprecedented opportunities for discovery. The GAIA mission's catalog, containing a large number of light sources (mostly stars) with several parameters such as sky position and proper motion, is playing a significant role in advancing astronomy research and has been crucial in ...
Reem Alghamdi, Markus Hadwiger, Guido Reina, Alberto Jaspe‐Villanueva   +3 more
wiley   +1 more source

Silicate Extinction Profile Based on the Stellar Spectrum by Spitzer/IRS

The Astrophysical Journal
The 9.7 and 18 μ m interstellar spectral features, arising from the Si–O stretching and O–Si–O bending modes of amorphous silicate dust, are the strongest extinction features in the infrared.
Zhenzhen Shao, Biwei Jiang
doaj   +1 more source

VLT/UVES Observations of Interstellar Molecules and Diffuse Bands in the Magellanic Clouds

, 2006
We discuss the abundances of interstellar CH, CH+, and CN in the Magellanic Clouds (MC), derived from spectra of 7 SMC and 13 LMC stars obtained (mostly) with the VLT/UVES.
Adamson A. J., Ballester P., Brunet J. P., Cami J., Chin Y.-N., Crawford I. A., D. E. Welty, D. L. Lambert, Danks A. C., D’Odorico S., Fukui Y., Gredel R., Gredel R., Heger M. L., Henkel C., Israel F. P., J. A. Thorburn, Jenniskens P., Jenniskens P., Johansson L. E. B., Koornneef J., Krelowski J., Lequeux J., Magain P., Mattila K., Mizuno N., R. Gredel, S. R. Federman, Snow T. P., Snow T. P., Snow T. P., Sonnentrucker P., Thaddeus P., Vladilo G., Yamaguchi R., Yamaguchi R.   +35 more
core   +1 more source

The carbon abundance in diffuse interstellar clouds

The Astrophysical Journal, 1981
When N/sub H2/roughly-equal1-40 x 10/sup 19/ cm/sup -2/ in a given direction, or f equivalent 2N/sub H2//N/sub H/>10/sup -1.4/, the column densities of C I and H/sub 2/ are strongly correlated even though N/sub C/ /sub i/ and N/sub H/ are not. All or most of the observed C I in such directions is harbored by a single, predominantly molecular (H/sub 2/>>
openaire   +1 more source

Interstellar shocks and molecular CH/+/ in diffuse clouds

The Astrophysical Journal, 1980
The influence of shocks on the abundances of molecules in diffuse interstellar clouds is investigated with special emphasis on molecular CH/sup +/. Idealized shocks with plausible parameters are found to produce column densities for CH/sup +/ in the hot, postshock gas which are comparable with measured values in interstellar clouds (up to about 10/sup ...
M. Elitzur, W. D. Watson
openaire   +1 more source

The Chemistry of Interstellar OH+, H2O+, and H3O+: Inferring the Cosmic Ray Ionization Rates from Observations of Molecular Ions

, 2012
We model the production of OH+, H2O+, and H3O+ in interstellar clouds, using a steady state photodissociation region code that treats the freeze-out of gas species, grain surface chemistry, and desorption of ices from grains.
Badnell, Bakes, Cartledge, D. Neufeld, Dalgarno, David Hollenbach, Draine, Goicoechea, Goicoechea, Habing, Heiles, Heiles, Hollenbach, Indriolo, Indriolo, J. R. Goicoechea, Jensen, Jensen, Jochims, Joulain, Krełowski, Le Petit, M. J. Kaufman, M. Wolfire, Mathis, Meyer, Rimmer, Sofia, Weingartner, Weingartner, Wolfire, Wolfire   +31 more
core   +1 more source

Star formation in a diffuse high-altitude cloud?

, 2016
A recent discovery of two stellar clusters associated with the diffuse high-latitude cloud HRK 81.4-77.8 has important implications for star formation in the Galactic halo.
Kerp, J., Lenz, D., Roehser, T.
core   +1 more source

Composition, structure and chemistry of interstellar dust [PDF]

The observational constraints on the composition of the interstellar dust are analyzed. The dust in the diffuse interstellar medium consists of a mixture of stardust (amorphous silicates, amorphous carbon, polycyclic aromatic hydrocarbons, and graphite ...
Allamandola, Louis J., Tielens, Alexander G. G. M.   +1 more
core   +1 more source

Life Cycle of Dust in the Magellanic Clouds and the Milky Way

, 2014
To a great extent, our understanding of the life cycle of dust is based on the observational and theoretical studies of the Milky Way and the Magellanic Clouds, which will be the topic of this contribution. Over past years, a large volume of observations
Henning, Thomas, Zhukovska, Svitlana
core   +1 more source