Journal article
Analytic scaling of flux profiles from thermalized slabs in voigt partial frequency redistribution versus Doppler complete redistribution
The Astrophysical journal, Vol.497(1), pp.458-463
04/10/1998
DOI: 10.1086/305460
Abstract
Simplified resonance-line flux calculations sometimes assume complete redistribution (CRD) over the Doppler core and neglect the partially coherent Lorentz wings in order to avoid modeling partial frequency redistribution (PRD). This approach preserves the basic scaling of the thermalization properties, but its quantitative reliability has not been systematically investigated. To obtain more reasonable estimates for PRD lines, an analytic technique, termed the comoving-frame partially coherent scattering approximation, is used here. Together with second-order escape methods, this technique leads to an analytic approximation for the line flux emerging in collisionally dominated resonance lines. The result is no more computationally demanding than similar methods in CRD.
In contrast, the assumption of CRD over a Doppler profile may underestimate the integrated flux by factors of 3 or more for very thick slabs. The parameter domain where CRD over a Doppler profile remains valid, for obtaining either the total line flux, or even more stringently, its frequency profile, is specified.
Details
- Title: Subtitle
- Analytic scaling of flux profiles from thermalized slabs in voigt partial frequency redistribution versus Doppler complete redistribution
- Creators
- K G Gayley - Bartol Research Institute, 217 Sharp Lab, Newark, DE 19716
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal, Vol.497(1), pp.458-463
- Publisher
- Univ Chicago Press
- DOI
- 10.1086/305460
- ISSN
- 0004-637X
- eISSN
- 1538-4357
- Number of pages
- 6
- Language
- English
- Date published
- 04/10/1998
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984428823502771
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