The spectral energy distribution and emission-line properties of the narrow-line Seyfert 1 galaxy Arakelian 564

P. Romano, S. Mathur, T. J. Turner, S. B. Kraemer, D. M. Crenshaw, B. M. Peterson, R. W. Pogge, W. N. Brandt, I. M. George, K. Horne, G. A. Kriss, H. Netzer, O. Shemmer, W. Wamsteker

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Abstract

We present the intrinsic spectral energy distribution (SED) of the narrow-line Seyfert 1 galaxy (NLS1) Ark 564, constructed with contemporaneous data obtained during a multiwavelength, multisatellite observing campaign in 2000 and 2001. We compare this SED with that of the NLS1 Ton S180 and with those obtained for broad-line Seyfert 1 galaxies to infer how the relative accretion rates vary among the Seyfert 1 population. Although the peak of the SED is not well constrained, in our parameterization most of the energy of this object is emitted in the 10-100 eV regime, constituting roughly half of the emitted energy in the optical/X-ray ranges. This is consistent with a primary spectral component peaking in the extreme-UV/soft X-ray band and with diskcorona models, hence high accretion rates. Indeed, we estimate that ṁ ≈ 1. We also address the issue of the energy budget in this source by examining the emission lines observed in its spectrum, and we constrain the physical properties of the line-emitting gas through photoionization modeling. The available data suggest that the line-emitting gas is characterized by log n ≈ 11 and log U ≈ 0 and is stratified around log U ≈ 0. Our estimate of the radius of the Hβ-emitting region RBLR ≈ 10 ± 2 It-days is consistent with the RBLR-luminosity relationships found for Seyfert 1 galaxies, which indicates that the narrowness of the emission lines in this NLS1 is not due to the broad-line region being relatively farther away from the central mass than in broad-line Seyfert 1 galaxies of comparable luminosity. We also find evidence for supersolar metallicity in this NLS1. We show that the emission lines are not good diagnostics for the underlying SEDs and that the absorption line studies offer a far more powerful tool to determine the ionizing continuum of active galactic nuclei, especially if one is comparing the lower and higher ionization lines.

Original languageEnglish (US)
Pages (from-to)635-647
Number of pages13
JournalAstrophysical Journal
Volume602
Issue number2 I
DOIs
StatePublished - Feb 20 2004

Fingerprint

spectral energy distribution
galaxies
energy
accretion
luminosity
energy budget
gas
energy budgets
parameterization
ionization
physical property
estimates
distribution
gases
active galactic nuclei
metallicity
photoionization
x rays
physical properties
continuums

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Romano, P., Mathur, S., Turner, T. J., Kraemer, S. B., Crenshaw, D. M., Peterson, B. M., ... Wamsteker, W. (2004). The spectral energy distribution and emission-line properties of the narrow-line Seyfert 1 galaxy Arakelian 564. Astrophysical Journal, 602(2 I), 635-647. https://doi.org/10.1086/381235
Romano, P. ; Mathur, S. ; Turner, T. J. ; Kraemer, S. B. ; Crenshaw, D. M. ; Peterson, B. M. ; Pogge, R. W. ; Brandt, W. N. ; George, I. M. ; Horne, K. ; Kriss, G. A. ; Netzer, H. ; Shemmer, O. ; Wamsteker, W. / The spectral energy distribution and emission-line properties of the narrow-line Seyfert 1 galaxy Arakelian 564. In: Astrophysical Journal. 2004 ; Vol. 602, No. 2 I. pp. 635-647.
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abstract = "We present the intrinsic spectral energy distribution (SED) of the narrow-line Seyfert 1 galaxy (NLS1) Ark 564, constructed with contemporaneous data obtained during a multiwavelength, multisatellite observing campaign in 2000 and 2001. We compare this SED with that of the NLS1 Ton S180 and with those obtained for broad-line Seyfert 1 galaxies to infer how the relative accretion rates vary among the Seyfert 1 population. Although the peak of the SED is not well constrained, in our parameterization most of the energy of this object is emitted in the 10-100 eV regime, constituting roughly half of the emitted energy in the optical/X-ray ranges. This is consistent with a primary spectral component peaking in the extreme-UV/soft X-ray band and with diskcorona models, hence high accretion rates. Indeed, we estimate that ṁ ≈ 1. We also address the issue of the energy budget in this source by examining the emission lines observed in its spectrum, and we constrain the physical properties of the line-emitting gas through photoionization modeling. The available data suggest that the line-emitting gas is characterized by log n ≈ 11 and log U ≈ 0 and is stratified around log U ≈ 0. Our estimate of the radius of the Hβ-emitting region RBLRHβ ≈ 10 ± 2 It-days is consistent with the RBLRHβ-luminosity relationships found for Seyfert 1 galaxies, which indicates that the narrowness of the emission lines in this NLS1 is not due to the broad-line region being relatively farther away from the central mass than in broad-line Seyfert 1 galaxies of comparable luminosity. We also find evidence for supersolar metallicity in this NLS1. We show that the emission lines are not good diagnostics for the underlying SEDs and that the absorption line studies offer a far more powerful tool to determine the ionizing continuum of active galactic nuclei, especially if one is comparing the lower and higher ionization lines.",
author = "P. Romano and S. Mathur and Turner, {T. J.} and Kraemer, {S. B.} and Crenshaw, {D. M.} and Peterson, {B. M.} and Pogge, {R. W.} and Brandt, {W. N.} and George, {I. M.} and K. Horne and Kriss, {G. A.} and H. Netzer and O. Shemmer and W. Wamsteker",
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Romano, P, Mathur, S, Turner, TJ, Kraemer, SB, Crenshaw, DM, Peterson, BM, Pogge, RW, Brandt, WN, George, IM, Horne, K, Kriss, GA, Netzer, H, Shemmer, O & Wamsteker, W 2004, 'The spectral energy distribution and emission-line properties of the narrow-line Seyfert 1 galaxy Arakelian 564', Astrophysical Journal, vol. 602, no. 2 I, pp. 635-647. https://doi.org/10.1086/381235

The spectral energy distribution and emission-line properties of the narrow-line Seyfert 1 galaxy Arakelian 564. / Romano, P.; Mathur, S.; Turner, T. J.; Kraemer, S. B.; Crenshaw, D. M.; Peterson, B. M.; Pogge, R. W.; Brandt, W. N.; George, I. M.; Horne, K.; Kriss, G. A.; Netzer, H.; Shemmer, O.; Wamsteker, W.

In: Astrophysical Journal, Vol. 602, No. 2 I, 20.02.2004, p. 635-647.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The spectral energy distribution and emission-line properties of the narrow-line Seyfert 1 galaxy Arakelian 564

AU - Romano, P.

AU - Mathur, S.

AU - Turner, T. J.

AU - Kraemer, S. B.

AU - Crenshaw, D. M.

AU - Peterson, B. M.

AU - Pogge, R. W.

AU - Brandt, W. N.

AU - George, I. M.

AU - Horne, K.

AU - Kriss, G. A.

AU - Netzer, H.

AU - Shemmer, O.

AU - Wamsteker, W.

PY - 2004/2/20

Y1 - 2004/2/20

N2 - We present the intrinsic spectral energy distribution (SED) of the narrow-line Seyfert 1 galaxy (NLS1) Ark 564, constructed with contemporaneous data obtained during a multiwavelength, multisatellite observing campaign in 2000 and 2001. We compare this SED with that of the NLS1 Ton S180 and with those obtained for broad-line Seyfert 1 galaxies to infer how the relative accretion rates vary among the Seyfert 1 population. Although the peak of the SED is not well constrained, in our parameterization most of the energy of this object is emitted in the 10-100 eV regime, constituting roughly half of the emitted energy in the optical/X-ray ranges. This is consistent with a primary spectral component peaking in the extreme-UV/soft X-ray band and with diskcorona models, hence high accretion rates. Indeed, we estimate that ṁ ≈ 1. We also address the issue of the energy budget in this source by examining the emission lines observed in its spectrum, and we constrain the physical properties of the line-emitting gas through photoionization modeling. The available data suggest that the line-emitting gas is characterized by log n ≈ 11 and log U ≈ 0 and is stratified around log U ≈ 0. Our estimate of the radius of the Hβ-emitting region RBLRHβ ≈ 10 ± 2 It-days is consistent with the RBLRHβ-luminosity relationships found for Seyfert 1 galaxies, which indicates that the narrowness of the emission lines in this NLS1 is not due to the broad-line region being relatively farther away from the central mass than in broad-line Seyfert 1 galaxies of comparable luminosity. We also find evidence for supersolar metallicity in this NLS1. We show that the emission lines are not good diagnostics for the underlying SEDs and that the absorption line studies offer a far more powerful tool to determine the ionizing continuum of active galactic nuclei, especially if one is comparing the lower and higher ionization lines.

AB - We present the intrinsic spectral energy distribution (SED) of the narrow-line Seyfert 1 galaxy (NLS1) Ark 564, constructed with contemporaneous data obtained during a multiwavelength, multisatellite observing campaign in 2000 and 2001. We compare this SED with that of the NLS1 Ton S180 and with those obtained for broad-line Seyfert 1 galaxies to infer how the relative accretion rates vary among the Seyfert 1 population. Although the peak of the SED is not well constrained, in our parameterization most of the energy of this object is emitted in the 10-100 eV regime, constituting roughly half of the emitted energy in the optical/X-ray ranges. This is consistent with a primary spectral component peaking in the extreme-UV/soft X-ray band and with diskcorona models, hence high accretion rates. Indeed, we estimate that ṁ ≈ 1. We also address the issue of the energy budget in this source by examining the emission lines observed in its spectrum, and we constrain the physical properties of the line-emitting gas through photoionization modeling. The available data suggest that the line-emitting gas is characterized by log n ≈ 11 and log U ≈ 0 and is stratified around log U ≈ 0. Our estimate of the radius of the Hβ-emitting region RBLRHβ ≈ 10 ± 2 It-days is consistent with the RBLRHβ-luminosity relationships found for Seyfert 1 galaxies, which indicates that the narrowness of the emission lines in this NLS1 is not due to the broad-line region being relatively farther away from the central mass than in broad-line Seyfert 1 galaxies of comparable luminosity. We also find evidence for supersolar metallicity in this NLS1. We show that the emission lines are not good diagnostics for the underlying SEDs and that the absorption line studies offer a far more powerful tool to determine the ionizing continuum of active galactic nuclei, especially if one is comparing the lower and higher ionization lines.

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Romano P, Mathur S, Turner TJ, Kraemer SB, Crenshaw DM, Peterson BM et al. The spectral energy distribution and emission-line properties of the narrow-line Seyfert 1 galaxy Arakelian 564. Astrophysical Journal. 2004 Feb 20;602(2 I):635-647. https://doi.org/10.1086/381235