Comoving frame calculations of spectral lines formed in rapidly expanding media with the partial frequency redistribution function for zero natural line width

1980 ◽  
Vol 1 (1) ◽  
pp. 3-16 ◽  
Author(s):  
A. Peraiah
Keyword(s):  
Line Width ◽  
Spectral Lines ◽  
Partial Frequency ◽  
Frequency Redistribution ◽  
Natural Line Width ◽  
Partial Frequency Redistribution ◽  
Redistribution Function

Formation of spectral lines when there is partial frequency redistribution

Astrophysics ◽  
1987 ◽  
Vol 26 (1) ◽  
pp. 90-115 ◽  
Author(s):  
D. I. Nagirner
Keyword(s):  
Spectral Lines ◽  
Partial Frequency ◽  
Frequency Redistribution ◽  
Partial Frequency Redistribution

scholarly journals On the importance of partial frequency redistribution in modeling the scattering polarization

2014 ◽  
Vol 10 (S305) ◽  
pp. 351-359
Author(s):  
K. N. Nagendra
Keyword(s):  
Quantum Interference ◽  
Solar Spectrum ◽  
Resonance Scattering ◽  
Spectral Lines ◽  
Partial Frequency ◽  
Frequency Redistribution ◽  
Physical Mechanisms ◽  
Partial Frequency Redistribution ◽  
Scattering Matrices ◽  
Line Transfer

AbstractIt is well-known that partial frequency redistribution (PRD) is the basic physical mechanism to correctly describe radiative transfer in spectral lines. In the case of polarized line scattering, the PRD becomes particularly important to describe the line-wing polarization, instead of the well-known mechanism of complete redistribution (CRD). Historically, the two-level atom PRD scattering matrices for polarized line scattering were first derived in the 1970's, and later generalized to the case of arbitrary fields in 1997. The latter formulation of the PRD matrices have subsequently been used in the solution of the line transfer equation to successfully model the non-magnetic (resonance scattering) and the magnetic (Hanle scattering) polarization observations. In recent years, using the Kramers-Heisenberg approach, we formulated PRD matrices for various physical mechanisms like quantum interference involving fine- and hyperfine-structure states in a two-term atom. The effect of collisions is included in an approximate way. We have used these PRD matrices to model the observed linear polarization in several interesting lines of the Second Solar Spectrum. In this paper I present a few results which highlight the importance of PRD in the interpretation of the polarized Stokes profiles.

Formation of spectral lines with partial frequency redistribution

1976 ◽  
Vol 203 ◽  
pp. 660 ◽  
Author(s):  
J. N. Heasley ◽  
F. Kneer
Keyword(s):  
Spectral Lines ◽  
Partial Frequency ◽  
Frequency Redistribution ◽  
Partial Frequency Redistribution

scholarly journals 2-D Radiative Transfer Simulations with Angle-Dependent Partial Frequency Redistribution

1998 ◽  
Vol 167 ◽  
pp. 209-212
Author(s):  
A.B. Gorshkov ◽  
P. Heinzel
Keyword(s):  
Radiative Transfer ◽  
Numerical Simulations ◽  
Line Profiles ◽  
Partial Frequency ◽  
Frequency Redistribution ◽  
Partial Frequency Redistribution ◽  
Solar Prominences ◽  
Transfer Modelling ◽  
Redistribution Function

AbstractWe demonstrate how the angle-dependent redistribution function can be incorporated into the 2-D transfer modelling of solar prominences. Some preliminary numerical simulations have been performed and we present their results by comparing the emergent hydrogen Lα line profiles computed with the angle-averaged and angle-dependent redistributions.

Effects of Ambipolar Diffusion on Prominence Thread Models

1994 ◽  
Vol 144 ◽  
pp. 315-321 ◽  
Author(s):  
M. G. Rovira ◽  
J. M. Fontenla ◽  
J.-C. Vial ◽  
P. Gouttebroze
Keyword(s):  
Energy Balance ◽  
Transition Region ◽  
Ambipolar Diffusion ◽  
Line Profiles ◽  
Balance Equations ◽  
Model Calculations ◽  
Partial Frequency ◽  
Frequency Redistribution ◽  
Partial Frequency Redistribution ◽  
Theoretical Structure

AbstractWe have improved previous model calculations of the prominence-corona transition region including the effect of the ambipolar diffusion in the statistical equilibrium and energy balance equations. We show its influence on the different parameters that characterize the resulting prominence theoretical structure. We take into account the effect of the partial frequency redistribution (PRD) in the line profiles and total intensities calculations.

Frequency Redistribution Effects in the Formation of Lyman α in Prominences and Their Influence on the Ratio of Hα to Lα

1979 ◽  
Vol 44 ◽  
pp. 53-55
Author(s):  
R.W. Milkey ◽  
J.N. Heasley ◽  
E.J. Schmahl ◽  
O. Engvold
Keyword(s):  
Line Profile ◽  
Large Fraction ◽  
Partial Frequency ◽  
Frequency Redistribution ◽  
Partial Frequency Redistribution ◽  
Emergent Intensity

The effect of partial frequency redistribution in the formation of Lyman α in the chromosphere has been discussed by Milkey and Mihalas (1973) and others, and it has been shown that in this case the coherency of scattering in the wings of the line substantially influences the line profile. Although there are non-negligible sources for La photons within a prominence, a large fraction of the emergent line photons are due to scattering of photons incident on the surface of the prominence so that one expects that in a prominence the frequency redistribution processes will play an important role in determining the emergent intensity.

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