X-ray/ultraviolet campaign on the Mrk 279 AGN outflow

Constraining inhomogeneous absorber models

Nahum Arav, Jelle Kaastra, Gerard A. Kriss, Kirk T. Korista, Jack Gabel, Daniel Proga

Research output: Contribution to journalArticle

56 Citations (Scopus)

Abstract

We investigate the applicability of inhomogeneous absorber models in the formation of active galactic nucleus outflow absorption troughs. The models we explore are limited to monotonic gradients of absorbing column densities in front of a finite emission source. Our main finding is that simple power-law and Gaussian distributions are hard-pressed to fit the Mrk 279 high-quality UV outflow data. An acceptable fit for the O VI troughs can only be obtained by assuming unrealistic optical depth values (upward of 100). The strongest constraints arise from the attempt to fit the Lyman series troughs. In this case it is evident that even allowing for complete freedom of both the power-law exponent and the optical depth as a function of velocity cannot yield an acceptable fit. In contrast, partial covering models do yield good fits for the Lyman series troughs. We conclude that monotonic inhomogeneous absorber models that do not include a sharp edge in the optical depth distribution across the source are not an adequate physical model to explain the trough formation mechanism for the outflow observed in Mrk 279.

Original languageEnglish
Pages (from-to)665-672
Number of pages8
JournalAstrophysical Journal
Volume620
Issue number2 I
DOIs
StatePublished - Feb 20 2005
Externally publishedYes

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troughs
absorbers
trough
outflow
optical thickness
optical depth
x rays
power law
formation mechanism
normal density functions
active galactic nuclei
vertical distribution
coverings
exponents
gradients

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Space and Planetary Science

Cite this

X-ray/ultraviolet campaign on the Mrk 279 AGN outflow : Constraining inhomogeneous absorber models. / Arav, Nahum; Kaastra, Jelle; Kriss, Gerard A.; Korista, Kirk T.; Gabel, Jack; Proga, Daniel.

In: Astrophysical Journal, Vol. 620, No. 2 I, 20.02.2005, p. 665-672.

Research output: Contribution to journalArticle

Arav, Nahum ; Kaastra, Jelle ; Kriss, Gerard A. ; Korista, Kirk T. ; Gabel, Jack ; Proga, Daniel. / X-ray/ultraviolet campaign on the Mrk 279 AGN outflow : Constraining inhomogeneous absorber models. In: Astrophysical Journal. 2005 ; Vol. 620, No. 2 I. pp. 665-672.
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