Radiation hydrodynamics with many spectral lines: analytical expressions for a differentially moving slab.
An analytical solution of the comoving frame radiative transfer equation for a differentially moving slab is obtained and written in terms of the wavelength-integrated extinction coefficient ψ, the spectral thickness. It is shown that ψ is much smoother than the extinction coefficient χ(λ) itself an...
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| Main Authors: | , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
1997
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| In: |
Astronomy and astrophysics
Year: 1997, Volume: 320, Pages: 920-928 |
| ISSN: | 1432-0746 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://ui.adsabs.harvard.edu/abs/1997A&A...320..920B
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| Author Notes: | B. Baschek, C. Grueber, W. von Waldenfels, R. Wehrse |
| Summary: | An analytical solution of the comoving frame radiative transfer equation for a differentially moving slab is obtained and written in terms of the wavelength-integrated extinction coefficient ψ, the spectral thickness. It is shown that ψ is much smoother than the extinction coefficient χ(λ) itself and that it can be well approximated e.g. by a simple piecewise linear function. Compared to conventional algorithms it allows speed-ups of factors >=10^5^ in the calculation of wavelength-integrated quantities such as e.g. the total flux, the radiative force, or the energy balance with an accuracy of <=1%. The total number of lines which can be taken into account is essentially unlimited. A simple expression for the total flux in the diffusion limit is derived and the dependencies on the velocity gradient are discussed. |
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| Item Description: | Gesehen am 17.04.2023 |
| Physical Description: | Online Resource |
| ISSN: | 1432-0746 |