Partial redistribution in multilevel atoms. I. Method and application to the solar hydrogen line formation

Ivan - Hubeny, B. W. Lites

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

We present a robust method for solution of multilevel non-LTE line transfer problems including the effects of partial frequency redistribution (PRD). This method allows the self-consistent solution for redistribution of scattered line photons simultaneously in multiple transitions of a model atom, including the effects of resonant Raman scattering ("cross-redistribution") among lines sharing common upper levels. The method is incorporated into the framework of the widely used non-LTE complete redistribution code MULTI. We have applied this method to the problem of transfer in hydrogen lines in a plane-parallel solar model atmosphere, including cross-redistribution between the Hα and Lβ, using general redistribution functions for the Lα and Lβ lines which are not restricted by the impact approximation. The convergence properties of this method are demonstrated to be comparable to that of the equivalent complete redistribution problem. In this solar model, PRD in the Lα line produces the dominant influence on the level populations. It changes considerably the populations of the excited states of hydrogen, as well as the proton number density, in the middle and upper chromosphere, owing to modification of the Lα wing radiation. The population of the hydrogen ground state undergoes only modest changes, however. The influence of cross-redistribution and PRD in Lβ has a much smaller influence on the level populations but a considerable influence on the wing intensity of the Lβ line.

Original languageEnglish (US)
Pages (from-to)376-388
Number of pages13
JournalAstrophysical Journal
Volume455
Issue number1
StatePublished - Dec 10 1995
Externally publishedYes

Fingerprint

hydrogen
wings
atoms
chromosphere
Raman spectra
atmospheres
ground state
scattering
protons
method
photons
radiation
approximation
atmosphere
excitation
effect

Keywords

  • Atomic processes
  • Line: formation
  • Radiative transfer
  • Sun: chromosphere

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Partial redistribution in multilevel atoms. I. Method and application to the solar hydrogen line formation. / Hubeny, Ivan -; Lites, B. W.

In: Astrophysical Journal, Vol. 455, No. 1, 10.12.1995, p. 376-388.

Research output: Contribution to journalArticle

@article{57a8bfad7fdb4387ac8b2abafe47c0aa,
title = "Partial redistribution in multilevel atoms. I. Method and application to the solar hydrogen line formation",
abstract = "We present a robust method for solution of multilevel non-LTE line transfer problems including the effects of partial frequency redistribution (PRD). This method allows the self-consistent solution for redistribution of scattered line photons simultaneously in multiple transitions of a model atom, including the effects of resonant Raman scattering ({"}cross-redistribution{"}) among lines sharing common upper levels. The method is incorporated into the framework of the widely used non-LTE complete redistribution code MULTI. We have applied this method to the problem of transfer in hydrogen lines in a plane-parallel solar model atmosphere, including cross-redistribution between the Hα and Lβ, using general redistribution functions for the Lα and Lβ lines which are not restricted by the impact approximation. The convergence properties of this method are demonstrated to be comparable to that of the equivalent complete redistribution problem. In this solar model, PRD in the Lα line produces the dominant influence on the level populations. It changes considerably the populations of the excited states of hydrogen, as well as the proton number density, in the middle and upper chromosphere, owing to modification of the Lα wing radiation. The population of the hydrogen ground state undergoes only modest changes, however. The influence of cross-redistribution and PRD in Lβ has a much smaller influence on the level populations but a considerable influence on the wing intensity of the Lβ line.",
keywords = "Atomic processes, Line: formation, Radiative transfer, Sun: chromosphere",
author = "Hubeny, {Ivan -} and Lites, {B. W.}",
year = "1995",
month = "12",
day = "10",
language = "English (US)",
volume = "455",
pages = "376--388",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - Partial redistribution in multilevel atoms. I. Method and application to the solar hydrogen line formation

AU - Hubeny, Ivan -

AU - Lites, B. W.

PY - 1995/12/10

Y1 - 1995/12/10

N2 - We present a robust method for solution of multilevel non-LTE line transfer problems including the effects of partial frequency redistribution (PRD). This method allows the self-consistent solution for redistribution of scattered line photons simultaneously in multiple transitions of a model atom, including the effects of resonant Raman scattering ("cross-redistribution") among lines sharing common upper levels. The method is incorporated into the framework of the widely used non-LTE complete redistribution code MULTI. We have applied this method to the problem of transfer in hydrogen lines in a plane-parallel solar model atmosphere, including cross-redistribution between the Hα and Lβ, using general redistribution functions for the Lα and Lβ lines which are not restricted by the impact approximation. The convergence properties of this method are demonstrated to be comparable to that of the equivalent complete redistribution problem. In this solar model, PRD in the Lα line produces the dominant influence on the level populations. It changes considerably the populations of the excited states of hydrogen, as well as the proton number density, in the middle and upper chromosphere, owing to modification of the Lα wing radiation. The population of the hydrogen ground state undergoes only modest changes, however. The influence of cross-redistribution and PRD in Lβ has a much smaller influence on the level populations but a considerable influence on the wing intensity of the Lβ line.

AB - We present a robust method for solution of multilevel non-LTE line transfer problems including the effects of partial frequency redistribution (PRD). This method allows the self-consistent solution for redistribution of scattered line photons simultaneously in multiple transitions of a model atom, including the effects of resonant Raman scattering ("cross-redistribution") among lines sharing common upper levels. The method is incorporated into the framework of the widely used non-LTE complete redistribution code MULTI. We have applied this method to the problem of transfer in hydrogen lines in a plane-parallel solar model atmosphere, including cross-redistribution between the Hα and Lβ, using general redistribution functions for the Lα and Lβ lines which are not restricted by the impact approximation. The convergence properties of this method are demonstrated to be comparable to that of the equivalent complete redistribution problem. In this solar model, PRD in the Lα line produces the dominant influence on the level populations. It changes considerably the populations of the excited states of hydrogen, as well as the proton number density, in the middle and upper chromosphere, owing to modification of the Lα wing radiation. The population of the hydrogen ground state undergoes only modest changes, however. The influence of cross-redistribution and PRD in Lβ has a much smaller influence on the level populations but a considerable influence on the wing intensity of the Lβ line.

KW - Atomic processes

KW - Line: formation

KW - Radiative transfer

KW - Sun: chromosphere

UR - http://www.scopus.com/inward/record.url?scp=11944269308&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=11944269308&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:11944269308

VL - 455

SP - 376

EP - 388

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

ER -