Expanded iron uta spectra - Probing the thermal stability limits in AGN clouds

G. J. Ferland; R. Kisielius; F. P. Keenan; P. A.M. Van Hoof; V. Jonauskas; M. L. Lykins; R. L. Porter; R. J.R. Williams

doi:10.1088/0004-637X/767/2/123

Expanded iron uta spectra - Probing the thermal stability limits in AGN clouds

G. J. Ferland, R. Kisielius, F. P. Keenan, P. A.M. Van Hoof, V. Jonauskas, M. L. Lykins, R. L. Porter, R. J.R. Williams

Research output: Contribution to journal › Article › peer-review

9 Scopus citations

Abstract

The Fe unresolved transition arrays (UTAs) produce prominent features in the 15-17 Å wavelength range in the spectra of active galactic nuclei (AGNs). Here, we present new calculations of the energies and oscillator strengths of inner-shell lines from Fe XIV, Fe XV, and Fe XVI. These are crucial ions since they are dominant at inflection points in the gas thermal stability curve, and UTA excitation followed by autoionization is an important ionization mechanism for these species. We incorporate these, and data reported in previous papers, into the plasma simulation code Cloudy. This updated physics is subsequently employed to reconsider the thermally stable phases in absorbing media in AGNs. We show how the absorption profile of the Fe XIV UTA depends on density, due to the changing populations of levels within the ground configuration.

Original language	English
Article number	123
Journal	Astrophysical Journal
Volume	767
Issue number	2
DOIs	https://doi.org/10.1088/0004-637X/767/2/123
State	Published - Apr 20 2013

Keywords

X-rays: galaxies
atomic data
atomic processes
galaxies: active
line: formation
methods: numerical

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

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10.1088/0004-637X/767/2/123

Cite this

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title = "Expanded iron uta spectra - Probing the thermal stability limits in AGN clouds",

abstract = "The Fe unresolved transition arrays (UTAs) produce prominent features in the 15-17 {\AA} wavelength range in the spectra of active galactic nuclei (AGNs). Here, we present new calculations of the energies and oscillator strengths of inner-shell lines from Fe XIV, Fe XV, and Fe XVI. These are crucial ions since they are dominant at inflection points in the gas thermal stability curve, and UTA excitation followed by autoionization is an important ionization mechanism for these species. We incorporate these, and data reported in previous papers, into the plasma simulation code Cloudy. This updated physics is subsequently employed to reconsider the thermally stable phases in absorbing media in AGNs. We show how the absorption profile of the Fe XIV UTA depends on density, due to the changing populations of levels within the ground configuration.",

keywords = "X-rays: galaxies, atomic data, atomic processes, galaxies: active, line: formation, methods: numerical",

author = "Ferland, {G. J.} and R. Kisielius and Keenan, {F. P.} and {Van Hoof}, {P. A.M.} and V. Jonauskas and Lykins, {M. L.} and Porter, {R. L.} and Williams, {R. J.R.}",

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language = "English",

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AU - Ferland, G. J.

AU - Kisielius, R.

AU - Keenan, F. P.

AU - Van Hoof, P. A.M.

AU - Jonauskas, V.

AU - Lykins, M. L.

AU - Porter, R. L.

AU - Williams, R. J.R.

PY - 2013/4/20

Y1 - 2013/4/20

N2 - The Fe unresolved transition arrays (UTAs) produce prominent features in the 15-17 Å wavelength range in the spectra of active galactic nuclei (AGNs). Here, we present new calculations of the energies and oscillator strengths of inner-shell lines from Fe XIV, Fe XV, and Fe XVI. These are crucial ions since they are dominant at inflection points in the gas thermal stability curve, and UTA excitation followed by autoionization is an important ionization mechanism for these species. We incorporate these, and data reported in previous papers, into the plasma simulation code Cloudy. This updated physics is subsequently employed to reconsider the thermally stable phases in absorbing media in AGNs. We show how the absorption profile of the Fe XIV UTA depends on density, due to the changing populations of levels within the ground configuration.

AB - The Fe unresolved transition arrays (UTAs) produce prominent features in the 15-17 Å wavelength range in the spectra of active galactic nuclei (AGNs). Here, we present new calculations of the energies and oscillator strengths of inner-shell lines from Fe XIV, Fe XV, and Fe XVI. These are crucial ions since they are dominant at inflection points in the gas thermal stability curve, and UTA excitation followed by autoionization is an important ionization mechanism for these species. We incorporate these, and data reported in previous papers, into the plasma simulation code Cloudy. This updated physics is subsequently employed to reconsider the thermally stable phases in absorbing media in AGNs. We show how the absorption profile of the Fe XIV UTA depends on density, due to the changing populations of levels within the ground configuration.

KW - X-rays: galaxies

KW - atomic data

KW - atomic processes

KW - galaxies: active

KW - line: formation

KW - methods: numerical

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DO - 10.1088/0004-637X/767/2/123

M3 - Article

AN - SCOPUS:84876140238

SN - 0004-637X

VL - 767

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2

M1 - 123

ER -

Expanded iron uta spectra - Probing the thermal stability limits in AGN clouds

Abstract

Keywords

ASJC Scopus subject areas

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