X-ray/ultraviolet observing campaign of the Markarian 279 active galactic nucleus outflow

A close look at the absorbing/emitting gas with Chandra-LETGS

E. Costantini, J. S. Kaastra, N. Arav, G. A. Kriss, K. C. Steenbrugge, Jack Gabel, F. Verbunt, E. Behar, C. M. Gaskell, K. T. Korista, D. Proga, J. Kim Quijano, J. E. Scott, E. S. Klimek, C. H. Hedrick

Research output: Contribution to journalArticle

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Abstract

We present a Chandra-LETGS observation of the Seyfert 1 galaxy Mrk 279. This observation was simultaneous with HST-STIS and FUSE observations, in the context of a multiwavelength study of this source. The Chandra pointings were spread over ten days for a total exposure time of ∼360 ks. The maximal continuum flux variation is of the order of 30%. The spectrum of Mrk 279 shows evidence of broad emission features, especially at the wavelength of the O VII triplet. We quantitatively explore the possibility that this emission is produced in the broad line region (BLR). We modeled the broad UV emission lines sSOeen in the FUSE and HST-STIS spectra following the "locally optimally emitting cloud" approach. This method considers the emission from BLR as arising from "clouds" with a wide range of densities and distances from the source. We find that the X-ray lines luminosity derived from the best fit BLR model match the observed X-ray features, suggesting that the gas producing the UV lines is sufficient to account for the X-ray emission. The spectrum is absorbed by ionized gas whose total column density is ∼5 × 1020 cm-2. The absorption spectrum can be modeled by two distinct gas components (log ξ ∼ 0.47 and 2.49, respectively) both showing a significant outflow velocity. However, the data also allow for the presence of intermediate ionization components. The distribution of the column densities of such extra components as a function of the ionization parameter is not consistent with a continuous, power-law like, absorber, suggesting a complex structure for the gas outflow for Mrk 279.

Original languageEnglish
Pages (from-to)121-134
Number of pages14
JournalAstronomy and Astrophysics
Volume461
Issue number1
DOIs
StatePublished - Jan 2007
Externally publishedYes

Fingerprint

active galactic nuclei
outflow
Far UV Spectroscopic Explorer
gases
gas
x rays
ionization
ionized gases
absorption spectrum
absorbers
power law
luminosity
galaxies
continuums
wavelength
absorption spectra
wavelengths

All Science Journal Classification (ASJC) codes

  • Space and Planetary Science

Cite this

X-ray/ultraviolet observing campaign of the Markarian 279 active galactic nucleus outflow : A close look at the absorbing/emitting gas with Chandra-LETGS. / Costantini, E.; Kaastra, J. S.; Arav, N.; Kriss, G. A.; Steenbrugge, K. C.; Gabel, Jack; Verbunt, F.; Behar, E.; Gaskell, C. M.; Korista, K. T.; Proga, D.; Kim Quijano, J.; Scott, J. E.; Klimek, E. S.; Hedrick, C. H.

In: Astronomy and Astrophysics, Vol. 461, No. 1, 01.2007, p. 121-134.

Research output: Contribution to journalArticle

Costantini, E, Kaastra, JS, Arav, N, Kriss, GA, Steenbrugge, KC, Gabel, J, Verbunt, F, Behar, E, Gaskell, CM, Korista, KT, Proga, D, Kim Quijano, J, Scott, JE, Klimek, ES & Hedrick, CH 2007, 'X-ray/ultraviolet observing campaign of the Markarian 279 active galactic nucleus outflow: A close look at the absorbing/emitting gas with Chandra-LETGS', Astronomy and Astrophysics, vol. 461, no. 1, pp. 121-134. https://doi.org/10.1051/0004-6361:20065390
Costantini, E. ; Kaastra, J. S. ; Arav, N. ; Kriss, G. A. ; Steenbrugge, K. C. ; Gabel, Jack ; Verbunt, F. ; Behar, E. ; Gaskell, C. M. ; Korista, K. T. ; Proga, D. ; Kim Quijano, J. ; Scott, J. E. ; Klimek, E. S. ; Hedrick, C. H. / X-ray/ultraviolet observing campaign of the Markarian 279 active galactic nucleus outflow : A close look at the absorbing/emitting gas with Chandra-LETGS. In: Astronomy and Astrophysics. 2007 ; Vol. 461, No. 1. pp. 121-134.
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abstract = "We present a Chandra-LETGS observation of the Seyfert 1 galaxy Mrk 279. This observation was simultaneous with HST-STIS and FUSE observations, in the context of a multiwavelength study of this source. The Chandra pointings were spread over ten days for a total exposure time of ∼360 ks. The maximal continuum flux variation is of the order of 30{\%}. The spectrum of Mrk 279 shows evidence of broad emission features, especially at the wavelength of the O VII triplet. We quantitatively explore the possibility that this emission is produced in the broad line region (BLR). We modeled the broad UV emission lines sSOeen in the FUSE and HST-STIS spectra following the {"}locally optimally emitting cloud{"} approach. This method considers the emission from BLR as arising from {"}clouds{"} with a wide range of densities and distances from the source. We find that the X-ray lines luminosity derived from the best fit BLR model match the observed X-ray features, suggesting that the gas producing the UV lines is sufficient to account for the X-ray emission. The spectrum is absorbed by ionized gas whose total column density is ∼5 × 1020 cm-2. The absorption spectrum can be modeled by two distinct gas components (log ξ ∼ 0.47 and 2.49, respectively) both showing a significant outflow velocity. However, the data also allow for the presence of intermediate ionization components. The distribution of the column densities of such extra components as a function of the ionization parameter is not consistent with a continuous, power-law like, absorber, suggesting a complex structure for the gas outflow for Mrk 279.",
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T1 - X-ray/ultraviolet observing campaign of the Markarian 279 active galactic nucleus outflow

T2 - A close look at the absorbing/emitting gas with Chandra-LETGS

AU - Costantini, E.

AU - Kaastra, J. S.

AU - Arav, N.

AU - Kriss, G. A.

AU - Steenbrugge, K. C.

AU - Gabel, Jack

AU - Verbunt, F.

AU - Behar, E.

AU - Gaskell, C. M.

AU - Korista, K. T.

AU - Proga, D.

AU - Kim Quijano, J.

AU - Scott, J. E.

AU - Klimek, E. S.

AU - Hedrick, C. H.

PY - 2007/1

Y1 - 2007/1

N2 - We present a Chandra-LETGS observation of the Seyfert 1 galaxy Mrk 279. This observation was simultaneous with HST-STIS and FUSE observations, in the context of a multiwavelength study of this source. The Chandra pointings were spread over ten days for a total exposure time of ∼360 ks. The maximal continuum flux variation is of the order of 30%. The spectrum of Mrk 279 shows evidence of broad emission features, especially at the wavelength of the O VII triplet. We quantitatively explore the possibility that this emission is produced in the broad line region (BLR). We modeled the broad UV emission lines sSOeen in the FUSE and HST-STIS spectra following the "locally optimally emitting cloud" approach. This method considers the emission from BLR as arising from "clouds" with a wide range of densities and distances from the source. We find that the X-ray lines luminosity derived from the best fit BLR model match the observed X-ray features, suggesting that the gas producing the UV lines is sufficient to account for the X-ray emission. The spectrum is absorbed by ionized gas whose total column density is ∼5 × 1020 cm-2. The absorption spectrum can be modeled by two distinct gas components (log ξ ∼ 0.47 and 2.49, respectively) both showing a significant outflow velocity. However, the data also allow for the presence of intermediate ionization components. The distribution of the column densities of such extra components as a function of the ionization parameter is not consistent with a continuous, power-law like, absorber, suggesting a complex structure for the gas outflow for Mrk 279.

AB - We present a Chandra-LETGS observation of the Seyfert 1 galaxy Mrk 279. This observation was simultaneous with HST-STIS and FUSE observations, in the context of a multiwavelength study of this source. The Chandra pointings were spread over ten days for a total exposure time of ∼360 ks. The maximal continuum flux variation is of the order of 30%. The spectrum of Mrk 279 shows evidence of broad emission features, especially at the wavelength of the O VII triplet. We quantitatively explore the possibility that this emission is produced in the broad line region (BLR). We modeled the broad UV emission lines sSOeen in the FUSE and HST-STIS spectra following the "locally optimally emitting cloud" approach. This method considers the emission from BLR as arising from "clouds" with a wide range of densities and distances from the source. We find that the X-ray lines luminosity derived from the best fit BLR model match the observed X-ray features, suggesting that the gas producing the UV lines is sufficient to account for the X-ray emission. The spectrum is absorbed by ionized gas whose total column density is ∼5 × 1020 cm-2. The absorption spectrum can be modeled by two distinct gas components (log ξ ∼ 0.47 and 2.49, respectively) both showing a significant outflow velocity. However, the data also allow for the presence of intermediate ionization components. The distribution of the column densities of such extra components as a function of the ionization parameter is not consistent with a continuous, power-law like, absorber, suggesting a complex structure for the gas outflow for Mrk 279.

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