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

^*Corresponding author for this work

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

9 Citations (Scopus)

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
Pages (from-to)	1-12
Journal	Astrophysical Journal
Volume	767
Early online date	04 Apr 2013
DOIs	https://doi.org/10.1088/0004-637X/767/2/123
Publication status	Published - 20 Apr 2013

Keywords

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

ASJC Scopus subject areas

Space and Planetary Science
Astronomy and Astrophysics

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

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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doi = "10.1088/0004-637X/767/2/123",

language = "English",

volume = "767",

pages = "1--12",

journal = "Astrophysical Journal",

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TY - JOUR

T1 - Expanded iron uta spectra - Probing the thermal stability limits in AGN clouds

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 - atomic data

KW - atomic processes

KW - galaxies: active

KW - line: formation

KW - methods: numerical

KW - X-rays: galaxies

U2 - 10.1088/0004-637X/767/2/123

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

M3 - Article

AN - SCOPUS:84876140238

SN - 0004-637X

VL - 767

SP - 1

EP - 12

JO - Astrophysical Journal

JF - Astrophysical Journal

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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