Results 181 to 190 of about 30,446 (206)
Some of the next articles are maybe not open access.
Astrophysics, 1986
A model of two-layer cylindrical interstellar dust grains is used to calculate the interstellar extinction curves in the visible and near infrared regions of the spectrum and the ratio R /sub V/ of the total to the selective extinction. It is assumed that the core of the two-layer grains consists of ''astronomical silicate'' and the mantle of dirty ice
N. V. Voshchinnikov +2 more
openaire +1 more source
A model of two-layer cylindrical interstellar dust grains is used to calculate the interstellar extinction curves in the visible and near infrared regions of the spectrum and the ratio R /sub V/ of the total to the selective extinction. It is assumed that the core of the two-layer grains consists of ''astronomical silicate'' and the mantle of dirty ice
N. V. Voshchinnikov +2 more
openaire +1 more source
Interstellar Dust and Extinction
Annual Review of Astronomy and Astrophysics, 1987The ultraviolet (UV) region of the spectrum has been crucial in providing information on the nature of the material and size distribution of the particles of interstellar dust. Before there were any measurements of the UV properties of interstellar extinction, interstellar particles were believed to be composed primarily of dirty ices.
openaire +1 more source
Interstellar extinction and polarization by spheroidal dust grains
Astrophysics and Space Science, 1984Using the recently available exact computations of the scattering efficiencies of spheroidal particles numerical calculations of the extinction and polarization curves have been made for a distribution of particle sizes, shapes and orientations. The results are presented and compared with the observed interstellar extinction and polarization.
D. B. Vaidya, H. C. Bhatt, J. N. Desai
openaire +1 more source
Interstellar Dust Models: Extinction, Absorption and Emission
EAS Publications Series, 2009The observational constraints on interstellar dust are summarized. A dust model, consisting of a mixture of amorphous silicate, graphite, and PAH material that reproduces the observed interstellar extinction, is described. It is used to calculate the infrared emission expected when such dust is heated by radiation with the spectrum of interstellar ...
openaire +1 more source
Three-component dust models for interstellar extinction
Journal of Astrophysics and Astronomy, 2010Interstellar extinction curves obtained from the ‘extinction without standard’ method were used to constrain the dust characteristics in the mean ISM (R V = 3.1), along the lines of sight through a high latitude diffuse molecular cloud towards HD 210121 (R
openaire +1 more source
Modeling of interstellar extinction with composite dust grains
Astronomical & Astrophysical Transactions, 2002A model of interstellar dust must satisfy two conditions: dust grains have to be of the reasonable structure and chemical composition and explain basic observations. The latter are the interstellar extinction law and the depletion of interstellar elements. In this work, a new model of composite dust grains is considered.
openaire +1 more source
Applied Optics, 2002
Optical extinction spectra for particles of structurally disordered carbonaceous material (carbon black, soot) are discussed in terms of the effects of size and shape and the difference between coagulated and coalesced particles. For this purpose, the orientation-averaged specific extinction for several compact and open aggregates of spherical ...
Michael, Quinten +3 more
openaire +2 more sources
Optical extinction spectra for particles of structurally disordered carbonaceous material (carbon black, soot) are discussed in terms of the effects of size and shape and the difference between coagulated and coalesced particles. For this purpose, the orientation-averaged specific extinction for several compact and open aggregates of spherical ...
Michael, Quinten +3 more
openaire +2 more sources
Astrophysics and Space Science, 1979
A smooth surface layer of highly disordered olivine, (Mg, Fe)2SiO4, has been produced by exposure of polished, natural olivine to a dose of 5×1016 cm−2 of 1.5 MeV neon ions from a Van de Graaff accelerator. The dielectric functions of the disordered silicate in the wavelength range from 8 to 30 μm have been determined from analysis of specular ...
W. Kr�tschmer, Donald R. Huffman
openaire +1 more source
A smooth surface layer of highly disordered olivine, (Mg, Fe)2SiO4, has been produced by exposure of polished, natural olivine to a dose of 5×1016 cm−2 of 1.5 MeV neon ions from a Van de Graaff accelerator. The dielectric functions of the disordered silicate in the wavelength range from 8 to 30 μm have been determined from analysis of specular ...
W. Kr�tschmer, Donald R. Huffman
openaire +1 more source
Astrophysics, 1988
In the framework of the model of core-mantle (core consisting of astronomical silicate, mantle consisting of dirty ice) cylindrical grains partly oriented by the Davis-Greenstein mechanism, curves of the interstellar circular polarization q(/lambda/) are calculated.
openaire +1 more source
In the framework of the model of core-mantle (core consisting of astronomical silicate, mantle consisting of dirty ice) cylindrical grains partly oriented by the Davis-Greenstein mechanism, curves of the interstellar circular polarization q(/lambda/) are calculated.
openaire +1 more source
Dust Extinction from RF Regression of Interstellar Lines
2023González-Gaitán Santiago +1 more
openaire +2 more sources