J/ApJ/773/14 BOSS: quasar luminosity function (Ross+, 2013)
The SDSS-III Baryon Oscillation Spectroscopic Survey: the quasar luminosity
function from Data Release nine.
Ross N.P., McGreer I.D., White M., Richards G.T., Myers A.D.,
Palanque-Delabrouille N., Strauss M.A., Anderson S.F., Shen Y.,
Brandt W.N., Yeche C., Swanson M.E.C., Aubourg E., Bailey S., Bizyaev D.,
Bovy J., Brewington H., Brinkmann J., DeGraf C., Di Matteo T., Ebelke G.,
Fan X., Ge J., Malanushenko E., Malanushenko V., Mandelbaum R.,
Maraston C., Muna D., Oravetz D., Pan K., Paris I., Petitjean P.,
Schawinski K., Schlegel D.J., Schneider D.P., Silverman J.D., Simmons A.,
Snedden S., Streblyanska A., Suzuki N., Weinberg D.H., York D.
<Astrophys. J., 773, 14 (2013)>
=2013ApJ...773...14R 2013ApJ...773...14R
ADC_Keywords: Photometry, SDSS ; Redshifts ; QSOs ; Surveys
Keywords: cosmology: observations; galaxies: active; surveys;
galaxies: luminosity function, mass function; quasars: general
Abstract:
We present a new measurement of the optical quasar luminosity function
(QLF), using data from the Sloan Digital Sky Survey-III: Baryon
Oscillation Spectroscopic Survey (SDSS-III: BOSS). From the SDSS-III
Data Release Nine, a uniform sample of 22301 i≲21.8 quasars are
selected over an area of 2236deg2, with confirmed spectroscopic
redshifts between 2.2<z<3.5, filling in a key part of the
luminosity-redshift plane for optical quasar studies. The completeness
of the survey is derived through simulated quasar photometry, and this
completeness estimate is checked using a sample of quasars selected by
their photometric variability within the BOSS footprint. We
investigate the level of systematics associated with our quasar sample
using the simulations, in the process generating color-redshift
relations and a new quasar K-correction. We probe the faint end of the
QLF to Mi(z=2.2)~-24.5 and see a clear break in the QLF at
all redshifts up to z=3.5. A log-linear relation (in logΦ*-M*) for
a luminosity evolution and density evolution model is found to
adequately describe our data within the range 2.2<z<3.5; across this
interval the break luminosity increases by a factor of ∼2.6 while
Φ* declines by a factor of ∼8. At z≲2.2 our data are reasonably
well fit by a pure luminosity evolution model, and only a weak
signature of "AGN downsizing" is seen, in line with recent studies of
the hard X-ray luminosity function. We compare our measured QLF to a
number of theoretical models and find that models making a variety of
assumptions about quasar triggering and halo occupation can fit our
data over a wide range of redshifts and luminosities.
Description:
For our study, we use data from the SDSS-III: Baryon Oscillation
Spectroscopic Survey (BOSS; Dawson et al. 2013AJ....145...10D 2013AJ....145...10D) that is
specifically designed to target faint, g≲22, quasars in the redshift
range z=2.2-3.5 (Ross et al. 2012, J/ApJS/199/3). In this paper we
present the optical quasar luminosity function (QLF) from the first
two years of BOSS spectroscopy, data included in SDSS Data Release
Nine (DR9; Ahn et al. 2012, V/139).
The BOSS spectrographs and their SDSS predecessors are described in
detail by Smee et al. (2013AJ....146...32S 2013AJ....146...32S). They cover the wavelength
range 3600Å-10400Å with a resolving power of 1500-2600.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 113 35099 The SDSS-III BOSS DR9 Statistical Quasar Dataset
table5.dat 32 1408 The Quasar Selection Function for the fiducial model
described in the text; see also Fig. 6
table6.dat 12 252 The i-band K-corrections
table9.dat 41 143 The narrowly binned BOSS DR9 Quasar Luminosity
Function
table10.dat 41 180 The narrowly binned BOSS Quasar Luminosity Function
using data from 5731 (5476) 2.20<z<4.00 (3.50)
quasars selected via their variability signature
on Stripe 82 (Sec. 2.4)
--------------------------------------------------------------------------------
See also:
VII/270 : SDSS quasar catalog: tenth data release (Paris+, 2014)
VII/269 : SDSS Quasar Catalog, DR9Q (Paris+, 2012)
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
V/141 : Light-Motion Curve Catalogue (LMCC) in Stripe 82 (Bramich+ 2008)
VII/241 : The 2dF QSO Redshift Survey (Croom+ 2004)
J/ApJS/215/12 : BOSS narrow CIV absorption lines. II. zem>2.4 (Chen+, 2014)
J/ApJ/768/105 : z∼5 QLF from SDSS Stripe 82 (McGreer+, 2013)
J/ApJ/764/45 : Luminosity function of broad-line QSOs. II. (Kelly+, 2013)
J/ApJS/199/3 : The quasars MMT-BOSS pilot survey (Ross+, 2012)
J/ApJ/746/169 : Luminosity function of broad-line quasars (Shen+, 2012)
J/ApJ/743/125 : Likelihood method for QSOs selection (Kirkpatrick+, 2011)
J/ApJ/740/37 : Obscured AGN at z∼0.5-1 in the CDFS (Luo+, 2011)
J/AJ/141/182 : Radio and optical properties of QSOs (Kimball+, 2011)
J/A+A/530/A42 : X-ray properties of AGNs in XBS (Corral+, 2011)
J/ApJ/728/26 : QSO selection based on phot. variability (Macleod+, 2011)
J/ApJ/728/23 : GALEX UV-bright high-redshift quasars (Worseck+, 2011)
J/ApJS/186/378 : Hard X-ray survey from Swift-BAT 2004-2006 (Tueller+, 2010)
J/ApJ/710/1498 : QSO luminosity function at z∼4 (Glikman+, 2010)
J/ApJ/702/767 : CIV and FeKα Baldwin effects in AGNs (Wu+, 2009)
J/MNRAS/392/19 : The 2dF-SDSS QSO survey (Croom+, 2009)
J/ApJS/180/67 : Photometric selection of SDSS QSOs. II. (Richards+, 2009)
J/ApJ/690/20 : Models of the AGN & black hole populations (Shankar+, 2009)
J/AJ/136/2373 : Type 2 quasars from SDSS (Reyes+, 2008)
J/ApJ/675/49 : High-redshift QSOs in the SWIRE survey (Siana+, 2008)
J/ApJS/166/470 : SDSS-Spitzer type I QSOs IR photometry (Richards+, 2006)
J/AJ/131/2788 : Redshifts in the SFQS survey (Jiang+, 2006)
J/AJ/131/2766 : Quasar luminosity function from SDSS-DR3 (Richards+, 2006)
J/AJ/121/2308 : Sloan Digital Sky Survey quasar photometry (Richards+, 2001)
J/MNRAS/275/1102 : Evolution of quasar luminosity function (Hawkins+ 1995)
J/MNRAS/260/202 : Quasar luminosity function (Hawkins+, 1993)
http://www.sdss3.org/dr9 : SDSS-III home page for DR9.
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
12- 20 F9.6 deg DEdeg Declination in decimal degrees (J2000)
22- 27 F6.3 mag umag [18.3/26.5] SDSS u band magnitude
29- 33 F5.3 mag e_umag [0.01/5] Uncertainty in umag
35- 40 F6.3 mag gmag SDSS g band magnitude
42- 46 F5.3 mag e_gmag Uncertainty in gmag
48- 53 F6.3 mag rmag SDSS r band magnitude
55- 59 F5.3 mag e_rmag Uncertainty in rmag
61- 66 F6.3 mag imag [17.8/22.4] SDSS i band magnitude
68- 72 F5.3 mag e_imag [0.009/1.1] Uncertainty in imag
74- 79 F6.3 mag zmag [17.5/23.1] SDSS z band magnitude
81- 85 F5.3 mag e_zmag [0.01/2.5] Uncertainty in zmag
87- 92 F6.4 mag Ai [0.007/0.5] The i band extinction
94- 99 F6.3 --- z.b [0.2/5]?=-0 BOSS pipeline redshift (1)
101-106 F6.4 --- z.v [2.2/3.5] Visual inspection redshift (1)
108-113 F6.4 --- fsc [0.1/1] Spectro-coverage completeness;
see section 3.1.4
--------------------------------------------------------------------------------
Note (1): See Bolton et al. (2012AJ....144..144B 2012AJ....144..144B) and Paris et al.
(2012, VII/269) for more details.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 F6.3 mag istart The i band starting magnitude
8- 13 F6.3 mag iend The i band ending magnitude
15- 19 F5.3 mag zstart The z band starting magnitude
21- 25 F5.3 mag zend The z band ending magnitude
27- 32 F6.4 --- SFunc [0/1] Fraction of simulated quasars selected by
"Extreme Deconvolution" (XDQSO) algorithm (1)
--------------------------------------------------------------------------------
Note (1): We use the subset of the DR9 data that employs the
"Extreme Deconvolution" (XDQSO) algorithm of Bovy et al.
(2011ApJ...729..141B 2011ApJ...729..141B) to select quasars based on their optical
fluxes and colors to define a uniform sample. See section 2.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 F5.3 --- zem [2/4.6] Emission line redshift
7- 12 F6.3 --- KCor [-0.7/-0.1] The i band K-correction (1)
--------------------------------------------------------------------------------
Note (1): The K-correction is obtained using the fiducial quasar model
described in Section 3.4, and includes an updated treatment of the
emission line template compared to Richards et al. (2006,
J/AJ/131/2766). We define our K-correction to be our model
K-correction at Mi(z=2)=-26.0 (see main text for details).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table9.dat table10.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 F6.3 --- [2.2/3.9] Mean redshift of the bin
8- 14 F7.3 mag <iMag> Mean absolute i band magnitude at z=2
16- 22 F7.3 mag ibin Absolute i band magnitude bin center
24- 26 I3 --- NQ [1/576] Number of quasars in the bin
28- 33 F6.3 [Mpc-3/mag] logPhi [-8.6/-5.5]? Log of the quasar luminosity
function logΦ (1)
35- 41 F7.3 10-9Mpc-3/mag e_Phi [1.6/149]? Poisson error in Phi;
divided by 1e-9 (1)
--------------------------------------------------------------------------------
Note (1): The bins with no measured Φ are at the faint end limit where the
selection function is rapidly approaching, or is equal to, 0.00, thus
making our QLF estimation very uncertain.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Ross et al. BOSS targets. 2012ApJS..199....3R 2012ApJS..199....3R Cat. J/ApJS/199/3
Dawson et al. BOSS survey. 2013AJ....145...10D 2013AJ....145...10D
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 05-Feb-2015