A fresh look at AGN spectral energy distribution fitting with the XMM-SERVS AGN sample
A fresh look at AGN spectral energy distribution fitting with the XMM-SERVS AGN sample
We perform spectral energy distribution (SED) fitting to 711 luminous X-ray AGN at 0.7 < z < 4.5 using 10-bands of optical and infra-red photometric data for objects within XMM-SERVS. This fitting provided 510 reliable (reduced χ2 < 3) inferences on AGN and host galaxy properties. The AGN optical (3000 Å) luminosity inferred from SED-fitting is found to correlate with the measured X-ray (2–10 keV) luminosity, in good agreement with previous work. Using X-ray hardness as a proxy for AGN obscuration, we also study the differences in the host galaxy properties of obscured and unobscured AGNs. Both populations have consistent stellar masses (log10(M*/M⊙) = 10.88 ±0.09M⊙ and log10(M*/M⊙) = 10.8 ±0.1M⊙ for unobscured and obscured AGNs, respectively). We also find evidence for varying AGN emission line properties from a standard AGN template in 18.8 per cent of the sample with a reduced χ2 < 3 where the inclusion of an additional emission line strength free parameter was found to improve the quality of the fit. Comparison of these fits to SDSS spectra showed that emission line properties inferred from broad-band photometry were consistent with the results from spectroscopy for 91 per cent of objects. We find that the presence of weaker, more blueshifted emission lines as inferred from the SED fits are associated with more negative values of αox. While the correlation between the hardness of the ionizing SED and the emission line properties has been known for some time, we are able to derive this correlation purely from broad-band photometry.
galaxies: active, quasars: emission lines, quasars: general
5617–5628
Marshall, Adam
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Auger-Williams, Matthew W
d59eb63d-175c-4049-8870-dee08f24e91d
Banerji, Manda
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Maiolino, Roberto
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Bowler, Rebecca
f8281cb0-1c70-46f0-8a6e-878f5b114c8f
1 October 2022
Marshall, Adam
7cdc6e9f-ac13-4a54-b070-597054a9dc7e
Auger-Williams, Matthew W
d59eb63d-175c-4049-8870-dee08f24e91d
Banerji, Manda
ce0a04bf-70a4-4b64-9027-b1a01def7325
Maiolino, Roberto
2cf8e10b-197f-4394-9897-dd9031c04e97
Bowler, Rebecca
f8281cb0-1c70-46f0-8a6e-878f5b114c8f
Marshall, Adam, Auger-Williams, Matthew W, Banerji, Manda, Maiolino, Roberto and Bowler, Rebecca
(2022)
A fresh look at AGN spectral energy distribution fitting with the XMM-SERVS AGN sample.
Monthly Notices of the Royal Astronomical Society, 515 (4), .
(doi:10.1093/mnras/stac1619).
Abstract
We perform spectral energy distribution (SED) fitting to 711 luminous X-ray AGN at 0.7 < z < 4.5 using 10-bands of optical and infra-red photometric data for objects within XMM-SERVS. This fitting provided 510 reliable (reduced χ2 < 3) inferences on AGN and host galaxy properties. The AGN optical (3000 Å) luminosity inferred from SED-fitting is found to correlate with the measured X-ray (2–10 keV) luminosity, in good agreement with previous work. Using X-ray hardness as a proxy for AGN obscuration, we also study the differences in the host galaxy properties of obscured and unobscured AGNs. Both populations have consistent stellar masses (log10(M*/M⊙) = 10.88 ±0.09M⊙ and log10(M*/M⊙) = 10.8 ±0.1M⊙ for unobscured and obscured AGNs, respectively). We also find evidence for varying AGN emission line properties from a standard AGN template in 18.8 per cent of the sample with a reduced χ2 < 3 where the inclusion of an additional emission line strength free parameter was found to improve the quality of the fit. Comparison of these fits to SDSS spectra showed that emission line properties inferred from broad-band photometry were consistent with the results from spectroscopy for 91 per cent of objects. We find that the presence of weaker, more blueshifted emission lines as inferred from the SED fits are associated with more negative values of αox. While the correlation between the hardness of the ionizing SED and the emission line properties has been known for some time, we are able to derive this correlation purely from broad-band photometry.
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More information
Accepted/In Press date: 30 May 2022
e-pub ahead of print date: 15 July 2022
Published date: 1 October 2022
Additional Information:
Funding Information:
AM acknowledges funding from a Royal Society studentship. MWA-W acknowledges support from the Kavli Foundation. MB acknowledges funding from The Royal Society via a University Research Fellowship. The authors would like to thank Paul Hewett and Matthew Temple for useful discussions. RM acknowledges ERC Advanced Grant 695671 QUENCH, and support from the UK Science and Technology Facilities Council (STFC). RM also acknowledges funding from a research professorship from the Royal Society. RB acknowledges support from an STFC Ernest Rutherford Fellowship [grant number ST/T003596/1]. For the purpose of open access, the author has applied a CC-BY public copyright license to any author accepted manuscript version arising.
Publisher Copyright:
© 2022 The Author(s).
Keywords:
galaxies: active, quasars: emission lines, quasars: general
Identifiers
Local EPrints ID: 468742
URI: http://eprints.soton.ac.uk/id/eprint/468742
ISSN: 1365-2966
PURE UUID: 6cfb36d6-8d5f-4ef4-a3fb-f13eeaefd345
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Date deposited: 24 Aug 2022 16:38
Last modified: 17 Mar 2024 04:01
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Contributors
Author:
Adam Marshall
Author:
Matthew W Auger-Williams
Author:
Roberto Maiolino
Author:
Rebecca Bowler
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