J/ApJ/746/169 Luminosity function of broad-line quasars (Shen+, 2012)
The demographics of broad-line quasars in the mass-luminosity plane.
I. Testing FWHM-based virial black hole masses.
Shen Y., Kelly B.C.
<Astrophys. J., 746, 169 (2012)>
=2012ApJ...746..169S 2012ApJ...746..169S
ADC_Keywords: Active gal. nuclei ; QSOs ; Models
Keywords: black hole physics - galaxies: active - quasars: general - surveys
Abstract:
We jointly constrain the luminosity function (LF) and black hole mass
function (BHMF) of broad-line quasars with forward Bayesian modeling
in the quasar mass-luminosity plane, based on a homogeneous sample of
∼58000 Sloan Digital Sky Survey (SDSS) Data Release 7 quasars at
z∼0.3-5. We take into account the selection effect of the sample flux
limit; more importantly, we deal with the statistical scatter between
true BH masses and FWHM-based single-epoch virial mass estimates, as
well as potential luminosity-dependent biases of these mass estimates.
The LF is tightly constrained in the regime sampled by SDSS and makes
reasonable predictions when extrapolated to ∼3 mag fainter. Downsizing
is seen in the model LF. On the other hand, we find it difficult to
constrain the BHMF to within a factor of a few at z ≳ 0.7 (with Mg II
and C IV-based virial BH masses). This is mainly driven by the unknown
luminosity-dependent bias of these mass estimators and its degeneracy
with other model parameters, and secondly driven by the fact that SDSS
quasars only sample the tip of the active BH population at high
redshift. Nevertheless, the most likely models favor a positive
luminosity-dependent bias for Mg II and possibly for C IV, such that
at fixed true BH mass, objects with higher-than-average luminosities
have overestimated FWHM-based virial masses. There is tentative
evidence that downsizing also manifests itself in the active BHMF, and
the BH mass density in broad-line quasars contributes an insignificant
amount to the total BH mass density at all times. Within our model
uncertainties, we do not find a strong BH mass dependence of the mean
Eddington ratio, but there is evidence that the mean Eddington ratio
(at fixed BH mass) increases with redshift.
Description:
Our parent sample is the SDSS DR7 quasar catalog (Schneider et al.
2010, Cat. VII/260, superseded by Cat. VII/269), which contains 105783
bona fide quasars with i-band absolute magnitude Mi←22 and have at
least one broad emission line (FWHM>1000km/s) or have
interesting/complex absorption features. Among these quasars, about
half were targeted using the final quasar target algorithm described
in Richards et al. (2002AJ....123.2945R 2002AJ....123.2945R), and form a homogeneous,
statistical quasar sample (e.g., Richards et al. 2006,
Cat. J/AJ/131/2766; Shen et al. 2007, Cat. J/AJ/133/2222), which we
adopt in the current study.
The virial mass estimates and measurement errors for these quasars
were taken from Shen et al. (2011ApJS..194...45S 2011ApJS..194...45S).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 26 168 Binned DR7 Virial black hole mass function (BHMF)
table3.dat 27 322 Binned DR7 luminosity function (LF)
table4.dat 161 2814 Model LF and BHMF
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See also:
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
J/ApJS/194/42 : SDSS-DR3 MgII-based black hole masses (Rafiee+, 2011)
J/ApJ/699/800 : Mass functions of active black holes (Vestergaard+, 2009)
J/ApJS/176/355 : AGN X-Ray emission and black holes (Kelly+, 2008)
J/AJ/133/2222 : Clustering of high-redshift QSOs from SDSS (Shen+, 2007)
J/AJ/131/2766 : Quasar luminosity function from SDSS-DR3 (Richards+, 2006)
J/ApJ/614/91 : Black hole mass and accretion rate of AGNs (Wu+, 2004)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 F4.2 --- zbin [0.4/4.75] Redshift of the bin
6- 10 F5.2 [Msun] logM [7.5/10.25] Virial BH mass of the bin
12- 18 F7.3 [-] logPhi [-9/-5]?=-99.999 Log of comoving space density
logΦ (in Mpc-3(logMsun)-1 units)
20- 26 F7.3 [-] elogPhi [-9.1/-5.9]?=-99.999 Log of Φ uncertainty
logσ (in Mpc-3(logMsun)-1 units)
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 F4.2 --- zbin [0.4/4.75] Redshift of the bin
6- 11 F6.2 mag magz2 [-29.25/-22.65] Magnitude of the bin
13- 19 F7.3 [-] logPhi [-9.4/-5.6]?=-99.999 Log of comoving space
density logΦ (in Mpc-3mag-1 units)
21- 27 F7.3 [-] elogPhi [-9.6/-6.2]?=-99.999 Log of Φ uncertainty
logσ (in Mpc-3mag-1 units)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 F4.2 --- zbin [0.4/4.75] Redshift of the bin
6- 12 F7.3 mag magz2 [-31.91/-16.90] Absolute magnitude in bin
14- 18 F5.2 [10-7W] logL [42/48] Continuum luminosity of the bin
20- 26 F7.3 [-] logPhiL [-23.64/-4.58] Median LF (Mpc-3/dex) logΦo
28- 34 F7.3 [-] ElogPhiL The 84% percentile LF (Mpc-3/dex) logΦ+
36- 42 F7.3 [-] elogPhiL The 16% percentile LF (Mpc-3/dex) logΦ-
44- 49 F6.3 [Msun] logM [6/11] True Black Hole mass of the bin
51- 57 F7.3 [-] logPhiMa [-18.85/-4.28] Median BHMF for all BHs
logΦo (in Mpc-3logMsun-1 units)
59- 65 F7.3 [-] ElogPhiMa The 84% percentile BHMF for logPhiMa logΦ+
(in Mpc-3logMsun-1 units)
67- 73 F7.3 [-] elogPhiMa The 16% percentile BHMF for logPhiMa logΦ-
(in Mpc-3logMsun-1 units)
75- 82 F8.3 [-] logPhiMd [-40.15/-5.5]?=-999.999 Median BHMF logΦo
for detectable BHs (in Mpc-3logMsun-1)
84- 91 F8.3 [-] ElogPhiMd ?=-999.999 The 84% percentile BHMF logΦ+
for logPhiMd (in Mpc-3logMsun-1 units)
93-100 F8.3 [-] elogPhiMd ?=-999.999 The 16% percentile BHMF logΦ-
for logPhiMd (in Mpc-3logMsun-1 units)
102-107 F6.3 [-] logR [-4/1] Eddington ratio of the bin
109-116 F8.3 [-] logPhiRa [-107.43/-4.54] Median Eddington ratio function
(ERF) for all BHs (in Mpc-3/[-] units)
118-125 F8.3 [-] ElogPhiRa The 84% percentile ERF for logPhiRa logΦ+
(in Mpc-3/[-] units)
127-134 F8.3 [-] elogPhiRa The 16% percentile ERF for logPhiRa logΦ-
(in Mpc-3/[-] units)
136-143 F8.3 [-] logPhiRd [-218.9/-5.5]?=-999.999 Median ERF for
detectable BHs (in Mpc-3/[-] units)
145-152 F8.3 [-] ElogPhiRd ?=-999.999 The 84% percentile ERF logΦ+ for
logPhiRd (in Mpc-3/[-] units)
154-161 F8.3 [-] elogPhiRd ?=-999.999 The 16% percentile ERF logΦ- for
logPhiRd (in Mpc-3/[-] units)
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History:
From electronic version of the journal
References:
Kelly et al. Paper II. 2013ApJ...764...45K 2013ApJ...764...45K Cat. J/ApJ/764/45
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 16-Sep-2013