Dielectronic recombination of Fe 3pq ions: a key ingredient for describing x-ray absorption in active galactic nuclei

Research output: Contribution to journalArticle

49 Citations (Scopus)
89 Downloads (Pure)

Abstract

We have carried out multiconfiguration Breit-Pauli AUTOSTRUCTURE calculations for the dielectronic recombination (DR) of Fe8+-Fe12+ ions. We obtain total DR rate coefficients for the initial ground level that are an order of magnitude larger than those corresponding to radiative recombination (RR), at temperatures where Fe 3pq () ions are abundant in photoionized plasmas. The resultant total (DR+RR) rate coefficients are then an order of magnitude larger than those currently in use by photoionized plasma modeling codes such as CLOUDY, ION, and XSTAR. These rate coefficients, together with our previous results for and 1, are critical for determining the ionization balance of the M-shell Fe ions that give rise to the prominent unresolved-transition-array X-ray absorption feature found in the spectrum of many active galactic nuclei. This feature is poorly described by CLOUDY and ION, necessitating an ad hoc modification to the low-temperature DR rate coefficients. Such modifications are no longer necessary, and a rigorous approach to such modeling can now take place using these data.
Original languageEnglish
Pages (from-to)L73-L76
JournalAstrophysical Journal
Volume651
Issue number1
DOIs
Publication statusPublished - 1 Nov 2006

Fingerprint

x ray absorption
ingredients
active galactic nuclei
recombination
ion
radiative recombination
coefficients
ions
plasma
ionization
modeling
shell
x rays
rate
temperature

Keywords

  • atomic data
  • atomic processes
  • galaxies
  • active - galaxies
  • nuclei - X-rays
  • plasmas

Cite this

@article{874c83c5030849a893dee4c0b5aff865,
title = "Dielectronic recombination of Fe 3pq ions: a key ingredient for describing x-ray absorption in active galactic nuclei",
abstract = "We have carried out multiconfiguration Breit-Pauli AUTOSTRUCTURE calculations for the dielectronic recombination (DR) of Fe8+-Fe12+ ions. We obtain total DR rate coefficients for the initial ground level that are an order of magnitude larger than those corresponding to radiative recombination (RR), at temperatures where Fe 3pq () ions are abundant in photoionized plasmas. The resultant total (DR+RR) rate coefficients are then an order of magnitude larger than those currently in use by photoionized plasma modeling codes such as CLOUDY, ION, and XSTAR. These rate coefficients, together with our previous results for and 1, are critical for determining the ionization balance of the M-shell Fe ions that give rise to the prominent unresolved-transition-array X-ray absorption feature found in the spectrum of many active galactic nuclei. This feature is poorly described by CLOUDY and ION, necessitating an ad hoc modification to the low-temperature DR rate coefficients. Such modifications are no longer necessary, and a rigorous approach to such modeling can now take place using these data.",
keywords = "atomic data, atomic processes, galaxies, active - galaxies, nuclei - X-rays, plasmas",
author = "N.R. Badnell",
year = "2006",
month = "11",
day = "1",
doi = "10.1086/509739",
language = "English",
volume = "651",
pages = "L73--L76",
journal = "Astrophysical Journal",
issn = "0004-637X",
number = "1",

}

Dielectronic recombination of Fe 3pq ions: a key ingredient for describing x-ray absorption in active galactic nuclei. / Badnell, N.R.

In: Astrophysical Journal, Vol. 651, No. 1, 01.11.2006, p. L73-L76.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Dielectronic recombination of Fe 3pq ions: a key ingredient for describing x-ray absorption in active galactic nuclei

AU - Badnell, N.R.

PY - 2006/11/1

Y1 - 2006/11/1

N2 - We have carried out multiconfiguration Breit-Pauli AUTOSTRUCTURE calculations for the dielectronic recombination (DR) of Fe8+-Fe12+ ions. We obtain total DR rate coefficients for the initial ground level that are an order of magnitude larger than those corresponding to radiative recombination (RR), at temperatures where Fe 3pq () ions are abundant in photoionized plasmas. The resultant total (DR+RR) rate coefficients are then an order of magnitude larger than those currently in use by photoionized plasma modeling codes such as CLOUDY, ION, and XSTAR. These rate coefficients, together with our previous results for and 1, are critical for determining the ionization balance of the M-shell Fe ions that give rise to the prominent unresolved-transition-array X-ray absorption feature found in the spectrum of many active galactic nuclei. This feature is poorly described by CLOUDY and ION, necessitating an ad hoc modification to the low-temperature DR rate coefficients. Such modifications are no longer necessary, and a rigorous approach to such modeling can now take place using these data.

AB - We have carried out multiconfiguration Breit-Pauli AUTOSTRUCTURE calculations for the dielectronic recombination (DR) of Fe8+-Fe12+ ions. We obtain total DR rate coefficients for the initial ground level that are an order of magnitude larger than those corresponding to radiative recombination (RR), at temperatures where Fe 3pq () ions are abundant in photoionized plasmas. The resultant total (DR+RR) rate coefficients are then an order of magnitude larger than those currently in use by photoionized plasma modeling codes such as CLOUDY, ION, and XSTAR. These rate coefficients, together with our previous results for and 1, are critical for determining the ionization balance of the M-shell Fe ions that give rise to the prominent unresolved-transition-array X-ray absorption feature found in the spectrum of many active galactic nuclei. This feature is poorly described by CLOUDY and ION, necessitating an ad hoc modification to the low-temperature DR rate coefficients. Such modifications are no longer necessary, and a rigorous approach to such modeling can now take place using these data.

KW - atomic data

KW - atomic processes

KW - galaxies

KW - active - galaxies

KW - nuclei - X-rays

KW - plasmas

UR - http://arxiv.org/PS_cache/astro-ph/pdf/0608/0608339v1.pdf

UR - http://dx.doi.org/10.1086/509739

U2 - 10.1086/509739

DO - 10.1086/509739

M3 - Article

VL - 651

SP - L73-L76

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

ER -