Spectral Energy Distributions and Multiwavelength Selection of Type 1 Quasars

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 data, 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.

[1]  M. Im,et al.  The Spitzer Space Telescope Extragalactic First Look Survey: 24 μm Data Reduction, Catalog, and Source Identification , 2006, astro-ph/0603488.

[2]  I. Strateva,et al.  The X-Ray-to-Optical Properties of Optically Selected Active Galaxies over Wide Luminosity and Redshift Ranges , 2006, astro-ph/0602407.

[3]  D. Helfand,et al.  A Near-Infrared Spectral Template for Quasars , 2005, astro-ph/0511640.

[4]  Padova,et al.  Revisiting the infrared spectra of active galactic nuclei with a new torus emission model , 2005, astro-ph/0511428.

[5]  D. Eisenstein,et al.  An MMT Hectospec Redshift Survey of 24 μm Sources in the Spitzer First Look Survey , 2005, astro-ph/0512623.

[6]  M. Dickinson,et al.  Spitzer Number Counts of Active Galactic Nuclei in the GOODS Fields , 2005, astro-ph/0512007.

[7]  D. Padgett,et al.  Spitzer 70 and 160 μm Observations of the Extragalactic First Look Survey , 2005, astro-ph/0509649.

[8]  Michael J. Kurtz,et al.  Hectospec, the MMT’s 300 Optical Fiber‐Fed Spectrograph , 2005, astro-ph/0508554.

[9]  Caltech,et al.  The Infrared Array Camera Component of the Spitzer Space Telescope Extragalactic First Look Survey , 2005, astro-ph/0507143.

[10]  Mark Lacy,et al.  The obscuration by dust of most of the growth of supermassive black holes , 2005, Nature.

[11]  A. Szalay,et al.  Spectral Decomposition of Broad-Line AGNs and Host Galaxies , 2005, astro-ph/0509332.

[12]  D. Maoz,et al.  The Relationship between Luminosity and Broad-Line Region Size in Active Galactic Nuclei , 2005, astro-ph/0504484.

[13]  A. Myers,et al.  The 2dF-SDSS LRG and QSO Survey: The z<2.1 Quasar Luminosity Function from 5645 Quasars to g=21.85 , 2005, astro-ph/0504300.

[14]  S. Serjeant,et al.  Sloan Digital Sky Survey Quasars in the Spitzer Wide-Area Infrared Extragalactic Survey (SWIRE) ELAIS N1 Field: Properties and Spectral Energy Distributions , 2005 .

[15]  D. Berk,et al.  Soft X-Ray and Ultraviolet Emission Relations in Optically Selected AGN Samples , 2005, astro-ph/0503009.

[16]  Princeton,et al.  The Sloan Digital Sky Survey View of the Palomar-Green Bright Quasar Survey , 2005, astro-ph/0506022.

[17]  C. Dullemond,et al.  Clumpy tori around active galactic nuclei , 2005, astro-ph/0501570.

[18]  A. Szalay,et al.  GALEX Observations of the Sloan Digital Sky Survey: A Comparison , 2005 .

[19]  A. Szalay,et al.  Classification and Characterization of Objects from the Galaxy Evolution Explorer Survey and the Sloan Digital Sky Survey , 2005 .

[20]  J. Brinkmann,et al.  Active Galactic Nuclei in the Sloan Digital Sky Survey. II. Emission-Line Luminosity Function , 2005, astro-ph/0501042.

[21]  A. Szalay,et al.  The Galaxy Evolution Explorer: A Space Ultraviolet Survey Mission , 2004, astro-ph/0411302.

[22]  C. Megan Urry,et al.  Obscured Active Galactic Nuclei and the X-Ray, Optical, and Far-Infrared Number Counts of Active Galactic Nuclei in the GOODS Fields , 2004 .

[23]  Arjun Dey,et al.  Submitted to the Astrophysical Journal Letters Mid-Infrared Selection of Active Galaxies , 2004 .

[24]  E. L. Wright,et al.  The Infrared Array Camera (IRAC) Shallow Survey , 2004 .

[25]  Paul S. Smith,et al.  The Multiband Imaging Photometer for Spitzer (MIPS) , 2004 .

[26]  Tamas Budavari,et al.  An Empirical Algorithm for Broadband Photometric Redshifts of Quasars from the Sloan Digital Sky Survey , 2004, astro-ph/0408504.

[27]  Alexander G. Gray,et al.  EFFICIENT PHOTOMETRIC SELECTION OF QUASARS FROM THE SLOAN DIGITAL SKY SURVEY. II. ∼1, 000, 000 QUASARS FROM DATA RELEASE 6 , 2004, The Astrophysical Journal Supplement Series.

[28]  Cambridge,et al.  Infrared Number Counts of AGN in the GOODS Fields , 2004, astro-ph/0408099.

[29]  E. Wright,et al.  The Spitzer Space Telescope Mission , 2004, astro-ph/0406223.

[30]  Gary J. Melnick,et al.  In-flight performance and calibration of the Infrared Array Camera (IRAC) for the Spitzer Space Telescope , 2004, SPIE Astronomical Telescopes + Instrumentation.

[31]  F. Masci,et al.  Obscured and Unobscured Active Galactic Nuclei in the Spitzer Space Telescope First Look Survey , 2004, astro-ph/0405604.

[32]  M. Elvis,et al.  A PANCHROMATIC VIEW OF AGN , 2004, astro-ph/0403618.

[33]  R. Becker,et al.  FIRST-2Mass Sources below the APM Detection Threshold: A Population of Highly Reddened Quasars , 2004, astro-ph/0402386.

[34]  Takamitsu Miyaji,et al.  Cosmological Evolution of the Hard X-Ray Active Galactic Nucleus Luminosity Function and the Origin of the Hard X-Ray Background , 2003, astro-ph/0308140.

[35]  R. Nichol,et al.  Red and Reddened Quasars in the Sloan Digital Sky Survey , 2003, astro-ph/0305305.

[36]  William D. Cotton,et al.  The SIRTF First-Look Survey. I. VLA Image and Source Catalog , 2003 .

[37]  L. Wisotzki,et al.  The evolution of faint AGN between z ' 1 and z ' 5 from the COMBO-17 survey , 2003, astro-ph/0304072.

[38]  C. Dullemond,et al.  New radiative transfer models for obscuring tori in active galaxies , 2003, astro-ph/0303496.

[39]  M. Malkan,et al.  The Far-Infrared Spectral Energy Distributions of X-Ray-selected Active Galaxies , 2003, astro-ph/0302572.

[40]  Edward J. Wollack,et al.  First-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters , 2003, astro-ph/0302209.

[41]  Garching,et al.  A deep VLA survey at 6 cm in the Lockman Hole , 2002, astro-ph/0211625.

[42]  J. Dunlop,et al.  Quasars, their host galaxies and their central black holes , 2001, astro-ph/0108397.

[43]  S. Tremaine,et al.  The Slope of the Black Hole Mass versus Velocity Dispersion Correlation , 2002, astro-ph/0203468.

[44]  L. Ferrarese Beyond the Bulge: A Fundamental Relation between Supermassive Black Holes and Dark Matter Halos , 2002, astro-ph/0203469.

[45]  Ž. Ivezić,et al.  Dust Emission from Active Galactic Nuclei , 2002, astro-ph/0202405.

[46]  M. SubbaRao,et al.  Spectroscopic Target Selection in the Sloan Digital Sky Survey: The Quasar Sample , 2002, astro-ph/0202251.

[47]  R. Becker,et al.  The Reddest Quasars , 2001, astro-ph/0107441.

[48]  Fermilab,et al.  Photometric Redshifts of Quasars , 2001, astro-ph/0106038.

[49]  S. Serjeant,et al.  SWIRE: The SIRTF Wide‐Area Infrared Extragalactic Survey , 2001, astro-ph/0305375.

[50]  Walter A. Siegmund,et al.  The Sloan Digital Sky Survey: Technical Summary , 2000, astro-ph/0006396.

[51]  J. Turner X‐ray spectra of a large sample of quasars with ASCA , 2000, astro-ph/0003080.

[52]  Paul S. Smith,et al.  Reverberation Measurements for 17 Quasars and the Size-Mass-Luminosity Relations in Active Galactic Nuclei , 1999, astro-ph/9911476.

[53]  K. Nandra,et al.  X-Ray Observations of Optically Selected, Radio-quiet Quasars. I. The ASCA Results , 1999, astro-ph/9910218.

[54]  M. Malkan,et al.  Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei. I. Comparing the Photoionization and Reverberation Techniques , 1999, astro-ph/9905224.

[55]  Cambridge,et al.  A deep VLA survey at 20 CM of the ISO ELAIS survey regions , 1998, astro-ph/9805353.

[56]  D. Schlegel,et al.  Maps of Dust Infrared Emission for Use in Estimation of Reddening and Cosmic Microwave Background Radiation Foregrounds , 1998 .

[57]  P. Hall,et al.  An Optical Near-Infrared Study of Radio-loud Quasar Environments. I. Methods and z = 1-2 Observations , 1998, astro-ph/9806145.

[58]  D. Schlegel,et al.  Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds , 1997, astro-ph/9710327.

[59]  Bradley M. Peterson,et al.  An Introduction to Active Galactic Nuclei: Frontmatter , 1997 .

[60]  M. Fukugita,et al.  The Sloan Digital Sky Survey Photometric System , 1996 .

[61]  Richard L. White,et al.  The FIRST Survey: Faint Images of the Radio Sky at twenty centimeters , 1995 .

[62]  M. S. Oey,et al.  Atlas of quasar energy distributions , 1994 .

[63]  Robert Antonucci,et al.  Unified models for active galactic nuclei and quasars , 1993 .

[64]  H. Tananbaum,et al.  X-Ray properties of optically selected QSOs , 1986 .