J/ApJ/815/129 X-ray AGNs with Subaru/FMOS NIR observations (Suh+, 2015)
Eddington ratio distribution of X-ray-selected broad-line AGNs at 1.0<z<2.2.
Suh H., Hasinger G., Steinhardt C., Silverman J.D., Schramm M.
<Astrophys. J., 815, 129 (2015)>
=2015ApJ...815..129S 2015ApJ...815..129S (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; X-ray sources ; Spectra, infrared ; Redshifts
Keywords: black hole physics; galaxies: active; galaxies: nuclei;
quasars: general
Abstract:
We investigate the Eddington ratio distribution of X-ray-selected
broad-line active galactic nuclei (AGNs) in the redshift range
1.0<z<2.2, where the number density of AGNs peaks. Combining the
optical and Subaru/Fiber Multi Object Spectrograph near-infrared
spectroscopy, we estimate black hole masses for broad-line AGNs in the
Chandra Deep Field South (CDF-S), Extended Chandra Deep Field South
(E-CDF-S), and the XMM-Newton Lockman Hole (XMM-LH) surveys. AGNs with
similar black hole masses show a broad range of AGN bolometric
luminosities, which are calculated from X-ray luminosities, indicating
that the accretion rate of black holes is widely distributed. We find
a substantial fraction of massive black holes accreting significantly
below the Eddington limit at z≲2, in contrast to what is generally
found for luminous AGNs at high redshift. Our analysis of
observational selection biases indicates that the "AGN cosmic
downsizing" phenomenon can be simply explained by the strong evolution
of the comoving number density at the bright end of the AGN luminosity
function, together with the corresponding selection effects. However,
one might need to consider a correlation between the AGN luminosity
and the accretion rate of black holes, in which luminous AGNs have
higher Eddington ratios than low-luminosity AGNs, in order to
understand the relatively small fraction of low-luminosity AGNs with
high accretion rates in this epoch. Therefore, the observed downsizing
trend could be interpreted as massive black holes with low accretion
rates, which are relatively fainter than less-massive black holes with
efficient accretion.
Description:
We performed NIR spectroscopic observations for the AGN sources with
the FMOS high-resolution spectrographs on the Subaru telescope; in
J-short (0.92-1.12um), J-long (1.11-1.35um), H-short (1.40-1.60um),
and H-long (1.60-1.80um) coverage with a spectral resolution of R∼2200.
The data span the 2012 Mar 25-2013 Oct 24 period.
In addition to NIR spectra, we use existing optical spectroscopy (see
section 3.2).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 121 262 Subaru/FMOS spectroscopic observations
table3.dat 102 86 Emission line properties of Broad-line AGNs
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See also:
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
J/ApJ/764/45 : Luminosity function of broad-line quasars. II. (Kelly+, 2013)
J/ApJ/761/143 : Black hole masses of z∼1.4 AGNs from SXDS (Nobuta+, 2012)
J/ApJ/759/6 : SEDs of type I AGN in COSMOS. I. XMM-COSMOS (Elvis+, 2012)
J/ApJ/753/125 : NIR spectroscopy follow-up of 60 SDSS-DR7 QSOs (Shen+, 2012)
J/ApJS/198/1 : Photometry catalogs for the Lockman Hole (Fotopoulou+, 2012)
J/A+A/535/A80 : Type-2 QSOs in XMM-COSMOS (Mainieri+, 2011)
J/ApJS/195/10 : The CDF-S survey: 4Ms source catalogs (Xue+, 2011)
J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)
J/ApJS/194/42 : SDSS-DR3 MgII-based black hole masses (Rafiee+, 2011)
J/ApJ/733/60 : Accretion rate of AGNs from COSMOS surveys (Trump+, 2011)
J/A+A/529/A135 : AGN Opt/IR properties in Lockman Hole (Rovilos+, 2011)
J/ApJS/191/124 : Optical spectro. of ECDF-S X-ray sources (Silverman+, 2010)
J/ApJ/711/284 : Galaxy Zoo: AGN host galaxies (Schawinski+, 2010)
J/A+A/512/A34 : XMM-COSMOS Type 1 AGNs (Lusso+, 2010)
J/ApJ/708/137 : Broad-line AGNs in zCOSMOS survey (Merloni+, 2010)
J/ApJ/699/800 : Mass functions of active black holes (Vestergaard+, 2009)
J/ApJ/691/705 : AGN host galaxy morphologies in COSMOS (Gabor+, 2009)
J/ApJ/690/20 : Models of the AGN and black hole populations (Shankar+, 2009)
J/A+A/492/637 : Eddington ratios of faint AGN (Gavignaud+, 2008)
J/ApJ/680/169 : SDSS DR5 virial black hole masses (Shen+, 2008)
J/A+A/479/283 : XMM observations of the Lockman Hole (Brunner+, 2008)
J/A+A/444/79 : XMM obs. of Lockman Hole brightest AGNs (Mateos+, 2005)
J/ApJS/161/21 : Extended Chandra Deep Field-South survey (Lehmer+, 2005)
J/ApJS/155/271 : CDF-South: Optical spectroscopy (Szokoly+, 2004)
J/ApJS/139/369 : Chandra Deep Field South. 1 Ms catalog (Giacconi+, 2002)
J/A+A/371/833 : ROSAT Ultra Deep Survey (Lehmann+, 2001)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Field Field identifier ("CDF-S", "E-CDF-S" or
"XMM-LH")
9- 12 I4 --- ID [1/2506] Source identifier within the Field (G1)
14- 20 F7.3 deg RAdeg Right Ascension in decimal degrees (J2000)
22- 28 F7.3 deg DEdeg Declination in decimal degrees (J2000)
30- 34 F5.3 --- z [0.2/5.2] Best redshift estimate
36 A1 --- q_z Quality flag on z (2=reliable) (1)
37- 38 A2 --- n_z Note on z (2)
40- 46 F7.3 --- zspec [/4.5]?=-99 Previous spectroscopic redshift
48- 54 F7.3 --- zphot [/5.4]?=-99 Previous photometric redshift
56- 78 A23 --- Band Band used in the observation ("H-long"
(1.60-1.80um), "H-short" (1.40-1.60um) or
"J-long" (1.11-1.35um))
80-121 A42 --- Em Emission features used to determine redshift
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Note (1): We assign a quality flag that gives the confidence in the redshift
measurement as follows:
2 = reliable redshift due to high signal-to-noise ratio (S/N) spectra and
multiple spectral features.
1 = redshift is not securely identified due to either low S/N or the
presence of only a single emission line with no additional features.
Note (2): Note as follows:
++ = Newly discovered spectroscopic redshift with no previous spectroscopic
redshift.
+ = Newly discovered spectroscopic redshift with insecure previous
spectroscopic redshift.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Field Field identifier ("CDF-S", "E-CDF-S" or
"XMM-LH")
9- 12 I4 --- ID [1/2020] Source identifier within
the Field (G1)
14- 18 F5.3 --- z [0.5/3.5] Best redshift estimate
20- 24 F5.2 [10-7W] logLb [42.8/47.1] Log bolometric luminosity; erg/s
26- 29 F4.2 [10-7W] e_logLb [0/0.4] Uncertainty in logLb
31- 34 F4.2 [Msun] logMBH [6.5/9.3] Log black hole mass
36- 39 F4.2 [Msun] e_logMBH [0/0.9] Uncertainty in logMBH
41- 44 F4.2 [km/s] logHa [3.3/4.2]? Log Hα Full-Width at
Half-Maximum
46- 49 F4.2 [km/s] e_logHa ? Uncertainty in Ha
51- 54 F4.2 [km/s] logHb [3.3/3.9]? Log Hβ Full-Width at
Half-Maximum
56- 59 F4.2 [km/s] e_logHb ? Uncertainty in Hb
61- 64 F4.2 [km/s] logMgII [3.3/4.5]? Log Mg II Full-Width at
Half-Maximum
66- 69 F4.2 [km/s] e_logMgII ? Uncertainty in MgII
71- 75 F5.2 [10-7W] logLHa [41.7/44.2]? Log Hα luminosity; erg/s
77- 80 F4.2 [10-7W] e_logLHa ? Uncertainty in logLHa
82- 86 F5.2 [10-7W] logLHb [40.8/42.9]? Log Hβ luminosity; erg/s
88- 91 F4.2 [10-7W] e_logLHb ? Uncertainty in logLHb
93- 97 F5.2 [10-7W] logL3000 [43.2/46.1]? Log luminosity at 3000Å
in erg/s
99-102 F4.2 [10-7W] e_logL3000 ? Uncertainty in logL3000
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Global note:
Note (G1): From the published catalog of CDF-S (Xue et al. 2011, J/ApJS/195/10;
<[XLB2011] NNN> in Simbad), E-CDF-S (Lehmer et al. 2005,
J/ApJS/161/21; <[LBA2005] NNN> in Simbad), and XMM-LH (Brunner et al.
2008, J/A+A/479/283; <[BCH2008] NNNN> in Simbad).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 09-Mar-2016