Spectral Energy Distributions and Multiwavelength Selection of Type 1 Quasars

Richards, Gordon T.; Lacy, Mark; Storrie-Lombardi, L. J.; Hall, Patrick B.; Gallagher, S. C.; Hines, Dean C.; Fan, Xiaohui; Papovich, Casey; Berk, D. E. vanden; Trammell, George B.; Schneider, Donald P.; Vestergaard, M.; York, Donald G.; Jester, Sebastian; Anderson, Scott F.; Budavàri, Tamás; Szalay, Alexander S.

doi:10.1086/506525

Cited by 1,093 publications

(1,294 citation statements)

References 72 publications

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“…For the redshift range studied in this paper, the QSO selection efficiency is not strongly affected by the colour selection, i.e. the selection function is unity within the flux limit, 15.0 < i < 19.1 (Richards et al 2006a). We compute the MMR over several z bins.…”

Section: A3 Sdssmentioning

confidence: 77%

“…Richards et al 2006a;Bongiorno et al 2007;Croom et al 2009). The space density of the most luminous QSOs strongly increases towards z ∼ 2 and peaks around this redshift.…”

Section: Cosmic Evolution In Bh Mass and Accretion Ratementioning

confidence: 99%

“…We start from the SDSS DR7 QSO sample (Schneider et al 2010), consisting of 105 783 QSOs. We restrict this sample to the subset that has been selected by a uniform target selection algorithm (Richards et al 2002) and thus form a well-defined broad line AGN sample (Richards et al 2006a;Shen & Kelly 2012). The sample is magnitude limited to 15.0 < i < 19.1 below z = 2.9 and the target selection is based on multicolour information.…”

Section: Sdssmentioning

confidence: 99%

“…Alternatively, either a distribution of L bol at a given magnitude and redshift has to be assumed to determine Ωe(L bol , z), or an individual selection function for every object has to be defined. We apply the K-correction from Richards et al (2006a) to compute the absolute i-band magnitude normalized at z = 2 from the i-band flux and translate this to the continuum luminosity at 2500Å following Richards et al (2006a). We compute the bolometric luminosity from this L2500 estimate, assuming a constant correction factor fBC(2500Å) = 5 (Richards et al 2006b;Shen & Kelly 2012).…”

Section: Bolometric Luminositiesmentioning

confidence: 99%

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The cosmic growth of the active black hole population at 1 <z <2 in zCOSMOS, VVDS and SDSS

Schulze

Bongiorno

Gavignaud

et al. 2015

Monthly Notices of the Royal Astronomical Society

100

159

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We present a census of the active black hole population at 1 < z < 2, by constructing the bivariate distribution function of black hole mass and Eddington ratio, employing a maximum likelihood fitting technique. The study of the active black hole mass function (BHMF) and the Eddington ratio distribution function (ERDF) allows us to clearly disentangle the active galactic nuclei (AGN) downsizing phenomenon, present in the AGN luminosity function, into its physical processes of black hole mass downsizing and accretion rate evolution. We are utilizing type-1 AGN samples from three optical surveys (VVDS, zCOSMOS and SDSS), that cover a wide range of 3 dex in luminosity over our redshift interval of interest. We investigate the cosmic evolution of the AGN population as a function of AGN luminosity, black hole mass and accretion rate. Compared to z = 0, we find a distinct change in the shape of the BHMF and the ERDF, consistent with downsizing in black hole mass. The active fraction or duty cycle of type-1 AGN at z ∼ 1.5 is almost flat as a function of black hole mass, while it shows a strong decrease with increasing mass at z = 0. We are witnessing a phase of intense black hole growth, which is largely driven by the onset of AGN activity in massive black holes towards z = 2. We finally compare our results to numerical simulations and semi-empirical models and while we find reasonable agreement over certain parameter ranges, we highlight the need to refine these models in order to match our observations.

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Section: A3 Sdssmentioning

confidence: 77%

“…Richards et al 2006a;Bongiorno et al 2007;Croom et al 2009). The space density of the most luminous QSOs strongly increases towards z ∼ 2 and peaks around this redshift.…”

Section: Cosmic Evolution In Bh Mass and Accretion Ratementioning

confidence: 99%

Section: Sdssmentioning

confidence: 99%

Section: Bolometric Luminositiesmentioning

confidence: 99%

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The cosmic growth of the active black hole population at 1 <z <2 in zCOSMOS, VVDS and SDSS

Schulze

Bongiorno

Gavignaud

et al. 2015

Monthly Notices of the Royal Astronomical Society

100

159

View full text Add to dashboard Cite

show abstract

“…A popular method to distinguish star formation and AGN activity is to rely on Spectral Energy Distribution (SED) models. Some studies involving SED analysis are Elvis et al (1994), Richards et al (2006), Netzer et al (2007), Mor & Netzer (2012), Leipski et al (2013Leipski et al ( , 2014, and Xu et al (2015aXu et al ( , 2015b. In this work, we use a Python-based custom-written SED fitting routine (available upon inquiry).…”

Section: Introductionmentioning

confidence: 99%

Herschel Observed Stripe 82 Quasars and Their Host Galaxies: Connections Between Agn Activity and Host Galaxy Star Formation

2016

ApJ

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In this work, we present a study of 207 quasars selected from the Sloan Digital Sky Survey quasar catalogs and the Herschel Stripe 82 survey. Quasars within this sample are high-luminosity quasars with a mean bolometric luminosity of 10 46.4 erg s −1 . The redshift range of this sample is within z < 4, with a mean value of 1.5 ± 0.78. Because we only selected quasars that have been detected in all three Herschel-SPIRE bands, the quasar sample is complete yet highly biased. Based on the multi-wavelength photometric observation data, we conducted a spectral energy distribution (SED) fitting through UV to FIR. Parameters such as active galactic nucleus (AGN) luminosity, far-IR (FIR) luminosity, stellar mass, as well as many other AGN and galaxy properties are deduced from the SED fitting results. The mean star formation rate (SFR) of the sample is 419 M e yr −1 and the mean gas mass is ∼10 11.3 M e . All of these results point to an IR luminous quasar system. Compared with star formation main sequence (MS) galaxies, at least 80 out of 207 quasars are hosted by starburst galaxies. This supports the statement that luminous AGNs are more likely to be associated with major mergers. The SFR increases with the redshift up to z = 2. It is correlated with the AGN bolometric luminosity, where µ  L L FIR Bol 0.46 0.03 . The AGN bolometric luminosity is also correlated with the host galaxy mass and gas mass. Yet the correlation between L FIR and L Bol has higher significant level, implies that the link between AGN accretion and the SFR is more primal. The M BH /M * ratio of our sample is 0.02, higher than the value 0.005 in the local universe. It might indicate an evolutionary trend of the M BH -M * scaling relation.

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Massive Black Holes and the Evolution of Galaxies

Volonteri

Bellovary

2011

Reviews in Modern Astronomy

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Spectral Energy Distributions and Multiwavelength Selection of Type 1 Quasars

Cited by 1,093 publications

References 72 publications

The cosmic growth of the active black hole population at 1 <z <2 in zCOSMOS, VVDS and SDSS

The cosmic growth of the active black hole population at 1 <z <2 in zCOSMOS, VVDS and SDSS

Herschel Observed Stripe 82 Quasars and Their Host Galaxies: Connections Between Agn Activity and Host Galaxy Star Formation

Massive Black Holes and the Evolution of Galaxies

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