Spectral energy distributions and multiwavelength selection of type 1 quasars

Gordon T. Richards; Mark Lacy; Lisa J. Storrie-Lombardi; Patrick B. Hall; S. C. Gallagher; Dean C. Hines; Fan Xiaohui; Casey Papovich; Daniel E. Vanden Berk; George B. Trammell; Donald P. Schneider; Marianne Vestergaard; Donald G. York; Sebastian Jester; Scott F. Anderson; Tamás Budavári; Alexander S. Szalay

doi:10.1086/506525

Spectral energy distributions and multiwavelength selection of type 1 quasars

Gordon T. Richards^*, Mark Lacy, Lisa J. Storrie-Lombardi, Patrick B. Hall, S. C. Gallagher, Dean C. Hines, Fan Xiaohui, Casey Papovich, Daniel E. Vanden Berk, George B. Trammell, Donald P. Schneider, Marianne Vestergaard, Donald G. York, Sebastian Jester, Scott F. Anderson, Tamás Budavári, Alexander S. Szalay

^*Corresponding author for this work

720 Citations (Scopus)

Abstract

We present an analysis of the mid-infrared (MIR) and optical properties of type 1 (broad-line) quasars detected by the Spitzer Space Telescope. The MIR color-redshift relation is characterized to z ∼ 3, with predictions to z = 7. We demonstrate how combining MIR and optical colors can yield even more efficient selection of active galactic nuclei (AGNs) than MIR or optical colors alone. Composite spectral energy distributions (SEDs) are constructed for 259 quasars with both Sloan Digital Sky Survey and Spitzer photometry, supplemented by near-IR, GALEX, VLA, and ROSAT date, where available. We discuss how the spectral diversity of quasars influences the determination of bolometric luminosities and accretion rates; assuming the mean SED can lead to errors as large as 50% for individual quasars when inferring a bolometric luminosity from an optical luminosity. Finally, we show that careful consideration of the shape of the mean quasar SED and its redshift dependence leads to a lower estimate of the fraction of reddened / obscured AGNs missed by optical surveys as compared to estimates derived from a single mean MIR to optical flux ratio.

Original language	English
Journal	Astrophysical Journal, Supplement Series
Volume	166
Issue number	2
Pages (from-to)	470-497
Number of pages	28
ISSN	0067-0049
DOIs	https://doi.org/10.1086/506525
Publication status	Published - 1 Oct 2006
Externally published	Yes

Keywords

Catalogs
Galaxies: active
Infrared: galaxies
Quasars: general
Radio continuum: galaxies
Surveys
Ultraviolet: galaxies
X-rays: galaxies

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10.1086/506525

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Richards, G. T., Lacy, M., Storrie-Lombardi, L. J., Hall, P. B., Gallagher, S. C., Hines, D. C., Xiaohui, F., Papovich, C., Vanden Berk, D. E., Trammell, G. B., Schneider, D. P., Vestergaard, M., York, D. G., Jester, S., Anderson, S. F., Budavári, T., & Szalay, A. S. (2006). Spectral energy distributions and multiwavelength selection of type 1 quasars. Astrophysical Journal, Supplement Series, 166(2), 470-497. https://doi.org/10.1086/506525

Richards, GT, Lacy, M, Storrie-Lombardi, LJ, Hall, PB, Gallagher, SC, Hines, DC, Xiaohui, F, Papovich, C, Vanden Berk, DE, Trammell, GB, Schneider, DP, Vestergaard, M, York, DG, Jester, S, Anderson, SF, Budavári, T & Szalay, AS 2006, 'Spectral energy distributions and multiwavelength selection of type 1 quasars', Astrophysical Journal, Supplement Series, vol. 166, no. 2, pp. 470-497. https://doi.org/10.1086/506525

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title = "Spectral energy distributions and multiwavelength selection of type 1 quasars",

abstract = "We present an analysis of the mid-infrared (MIR) and optical properties of type 1 (broad-line) quasars detected by the Spitzer Space Telescope. The MIR color-redshift relation is characterized to z ∼ 3, with predictions to z = 7. We demonstrate how combining MIR and optical colors can yield even more efficient selection of active galactic nuclei (AGNs) than MIR or optical colors alone. Composite spectral energy distributions (SEDs) are constructed for 259 quasars with both Sloan Digital Sky Survey and Spitzer photometry, supplemented by near-IR, GALEX, VLA, and ROSAT date, where available. We discuss how the spectral diversity of quasars influences the determination of bolometric luminosities and accretion rates; assuming the mean SED can lead to errors as large as 50% for individual quasars when inferring a bolometric luminosity from an optical luminosity. Finally, we show that careful consideration of the shape of the mean quasar SED and its redshift dependence leads to a lower estimate of the fraction of reddened / obscured AGNs missed by optical surveys as compared to estimates derived from a single mean MIR to optical flux ratio.",

keywords = "Catalogs, Galaxies: active, Infrared: galaxies, Quasars: general, Radio continuum: galaxies, Surveys, Ultraviolet: galaxies, X-rays: galaxies",

author = "Richards, {Gordon T.} and Mark Lacy and Storrie-Lombardi, {Lisa J.} and Hall, {Patrick B.} and Gallagher, {S. C.} and Hines, {Dean C.} and Fan Xiaohui and Casey Papovich and {Vanden Berk}, {Daniel E.} and Trammell, {George B.} and Schneider, {Donald P.} and Marianne Vestergaard and York, {Donald G.} and Sebastian Jester and Anderson, {Scott F.} and Tam{\'a}s Budav{\'a}ri and Szalay, {Alexander S.}",

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doi = "10.1086/506525",

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AU - Richards, Gordon T.

AU - Lacy, Mark

AU - Storrie-Lombardi, Lisa J.

AU - Hall, Patrick B.

AU - Gallagher, S. C.

AU - Hines, Dean C.

AU - Xiaohui, Fan

AU - Papovich, Casey

AU - Vanden Berk, Daniel E.

AU - Trammell, George B.

AU - Schneider, Donald P.

AU - Vestergaard, Marianne

AU - York, Donald G.

AU - Jester, Sebastian

AU - Anderson, Scott F.

AU - Budavári, Tamás

AU - Szalay, Alexander S.

PY - 2006/10/1

Y1 - 2006/10/1

N2 - We present an analysis of the mid-infrared (MIR) and optical properties of type 1 (broad-line) quasars detected by the Spitzer Space Telescope. The MIR color-redshift relation is characterized to z ∼ 3, with predictions to z = 7. We demonstrate how combining MIR and optical colors can yield even more efficient selection of active galactic nuclei (AGNs) than MIR or optical colors alone. Composite spectral energy distributions (SEDs) are constructed for 259 quasars with both Sloan Digital Sky Survey and Spitzer photometry, supplemented by near-IR, GALEX, VLA, and ROSAT date, where available. We discuss how the spectral diversity of quasars influences the determination of bolometric luminosities and accretion rates; assuming the mean SED can lead to errors as large as 50% for individual quasars when inferring a bolometric luminosity from an optical luminosity. Finally, we show that careful consideration of the shape of the mean quasar SED and its redshift dependence leads to a lower estimate of the fraction of reddened / obscured AGNs missed by optical surveys as compared to estimates derived from a single mean MIR to optical flux ratio.

AB - We present an analysis of the mid-infrared (MIR) and optical properties of type 1 (broad-line) quasars detected by the Spitzer Space Telescope. The MIR color-redshift relation is characterized to z ∼ 3, with predictions to z = 7. We demonstrate how combining MIR and optical colors can yield even more efficient selection of active galactic nuclei (AGNs) than MIR or optical colors alone. Composite spectral energy distributions (SEDs) are constructed for 259 quasars with both Sloan Digital Sky Survey and Spitzer photometry, supplemented by near-IR, GALEX, VLA, and ROSAT date, where available. We discuss how the spectral diversity of quasars influences the determination of bolometric luminosities and accretion rates; assuming the mean SED can lead to errors as large as 50% for individual quasars when inferring a bolometric luminosity from an optical luminosity. Finally, we show that careful consideration of the shape of the mean quasar SED and its redshift dependence leads to a lower estimate of the fraction of reddened / obscured AGNs missed by optical surveys as compared to estimates derived from a single mean MIR to optical flux ratio.

KW - Catalogs

KW - Galaxies: active

KW - Infrared: galaxies

KW - Quasars: general

KW - Radio continuum: galaxies

KW - Surveys

KW - Ultraviolet: galaxies

KW - X-rays: galaxies

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U2 - 10.1086/506525

DO - 10.1086/506525

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AN - SCOPUS:33751584733

SN - 0004-637X

VL - 166

SP - 470

EP - 497

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2

ER -

Spectral energy distributions and multiwavelength selection of type 1 quasars

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Keywords

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