J/ApJ/778/98 Cross-correlation of SDSS QSOs and BOSS galaxies (Shen+, 2013)
Cross-correlation of SDSS DR7 quasars and DR10 BOSS galaxies: the weak
luminosity dependence of quasar clustering at z ∼ 0.5.
Shen Y., McBride C.K., White M., Zheng Z., Myers A.D., Guo H.,
Kirkpatrick J.A., Padmanabhan N., Parejko J.K., Ross N.P., Schlegel D.J.,
Schneider D.P., Streblyanska A., Swanson M.E.C., Zehavi I., Pan K.,
Bizyaev D., Brewington H., Ebelke G., Malanushenko V., Malanushenko E.,
Oravetz D., Simmons A., Snedden S.
<Astrophys. J., 778, 98 (2013)>
=2013ApJ...778...98S 2013ApJ...778...98S
ADC_Keywords: Galaxies, optical ; QSOs ; Surveys
Keywords: black hole physics; cosmology: observations; galaxies: active;
large-scale structure of universe; quasars: general; surveys
Abstract:
We present the measurement of the two-point cross-correlation function
(CCF) of 8198 Sloan Digital Sky Survey Data Release 7 quasars and
349608 Data Release 10 CMASS galaxies from the Baryonic Oscillation
Spectroscopic Survey (BOSS) at 0.3<z<0.9. The CCF can be reasonably
well fit by a power-law model ξQG(r)=(r/r0)-γ on
projected scales of rp=2-25h-1Mpc with r0=6.61±0.25h-1Mpc
and γ=1.69±0.07. We estimate a quasar linear bias of
bQ=1.38±0.10 at =0.53 from the CCF measurements, which
corresponds to a characteristic host halo mass of ∼4x1012h-1M☉,
compared with a ∼1013h-1M☉ characteristic host halo mass for
CMASS galaxies. Based on the clustering measurements, most quasars at
{overline}{z}∼0.5 are not the descendants of their higher luminosity
counterparts at higher redshift, which would have evolved into more
massive and more biased systems at low redshift. We divide the quasar
sample in luminosity and constrain the luminosity dependence of quasar
bias to be dbQ/dlogL=0.20±0.34 or 0.11±0.32 (depending on
different luminosity divisions) for quasar luminosities
-23.5>Mi(z=2)>-25.5, implying a weak luminosity dependence of
clustering for luminous quasars at {overline}{z}∼0.5. We compare our
measurements with theoretical predictions, halo occupation
distribution (HOD) models, and mock catalogs. These comparisons
suggest that quasars reside in a broad range of host halos. The host
halo mass distributions significantly overlap with each other for
quasars at different luminosities, implying a poor correlation between
halo mass and instantaneous quasar luminosity. We also find that the
quasar HOD parameterization is largely degenerate such that different
HODs can reproduce the CCF equally well, but with different satellite
fractions and host halo mass distributions. These results highlight
the limitations and ambiguities in modeling the distribution of
quasars with the standard HOD approach.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 129 25 Summary of quasar subsamples
table2.dat 37 550 Measurements of the cross-correlation function
(CCF) for the full sample and subsamples
table3.dat 153 550 Normalized covariance matrices from the full CCF
sample and from individual CCF subsamples
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See also:
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
VII/241 : The 2dF QSO Redshift Survey (Croom+ 2004)
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/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)
J/ApJ/690/20 : Models of the AGN and black hole populations (Shankar+, 2009)
J/ApJ/680/169 : SDSS DR5 virial black hole masses (Shen+, 2008)
J/ApJ/678/635 : Spectroscopy of quasar binary candidates (Myers+, 2008)
J/AJ/133/2222 : Clustering of high-redshift QSOs from SDSS (Shen+, 2007)
J/ApJ/658/99 : Pairs of QSO in SDSS-DR4 (Myers+, 2007)
J/ApJ/654/115 : DEEP2 Galaxy Redshift Survey: SDSS QSOs (Coil+, 2007)
J/AJ/131/2766 : Quasar luminosity function from SDSS-DR3 (Richards+, 2006)
J/AJ/131/1 : Binary quasars in the SDSS (Hennawi+, 2006)
J/ApJS/122/51 : Spectroscopic catalog of rich galaxy clusters (Dressler+ 1999)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [0/24] Sample number
4- 13 A10 --- Sample Sample identification
15- 18 I4 --- NQ [188/8198] Number of quasars
20- 25 I6 --- NG [78593/349608] Number of galaxies
27- 32 I6 --- N*QG [41766/879352] Total number of quasar-galaxy
pairs (1)
34- 39 F6.4 --- zmin [0.3/0.6] Minimum redsfhit
41- 46 F6.4 --- zmax [0.4/0.9] Maximum redshift
48- 54 F7.3 --- Mmin [-28.7/-23.8] Minimum mass
56- 62 F7.3 --- Mmax [-25.1/-22.5] Maximum mass
64- 68 F5.3 --- [0.4/0.7] Median redshift (2)
70- 76 F7.3 --- <Mi> [-25.7/-23.4] Median magnitude (2)
78- 82 F5.3 --- r0 [5.3/7.2] Best-fit power-law model correlation
length of the CCF (with fixed slope γ=1.7)
84- 88 F5.3 --- E_r0 [0.2/1] Positive error on r0
90- 94 F5.3 --- e_r0 [0.2/1.1] Negative error on r0
96- 99 F4.2 --- bG [2/2.2] Galaxy linear bias
101-104 F4.2 --- e_bG [0.02/0.05] bG uncertainty
106-109 F4.2 --- bQG [1.3/2] Linear bias of the cross-correlation
sample (3)
111-114 F4.2 --- E_bQG [0.06/0.3] Positive error on bQG
116-119 F4.2 --- e_bQG [0.06/0.3] Negative error on bQG
121-124 F4.2 --- bQGd [1.4/2.1] Linear bias of the cross-correlation
sample (4)
126-129 F4.2 --- e_bQGd [0.04/0.2] bQGd uncertainty
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Note (1): N*QG is the total number of quasar-galaxy pairs with
rp<50h-1Mpc and π<70h-1Mpc in a given cross-correlation
sample.
Note (2): The median redshift and magnitude are the pair count- (with
rp<50h-1Mpc and π<70h-1Mpc) weighted median values of
quasars.
Note (3): The linear bias of the cross-correlation sample fitted with the full
covariance matrix.
Note (4): fitted with diagonal elements of the covariance matrix.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Seq [0/24] Sample number as in Table 1
4- 10 F7.4 Mpc rp [0.1/49] Bin center rp (in Mpc/h)
12- 17 I6 --- QG Cross-pair number
19- 27 F9.4 Mpc wp Projected cross-correlation function (in Mpc/h)
29- 37 F9.4 Mpc e_wp Diagonal error in wp (in Mpc/h)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 6 F6.3 --- M1 [-1/1] Matrix element 1 (1)
8- 13 F6.3 --- M2 [-1/1] Matrix element 2 (1)
15- 20 F6.3 --- M3 [-1/1] Matrix element 3 (1)
22- 27 F6.3 --- M4 [-1/1] Matrix element 4 (1)
29- 34 F6.3 --- M5 [-1/1] Matrix element 5 (1)
36- 41 F6.3 --- M6 [-1/1] Matrix element 6 (1)
43- 48 F6.3 --- M7 [-1/1] Matrix element 7 (1)
50- 55 F6.3 --- M8 [-1/1] Matrix element 8 (1)
57- 62 F6.3 --- M9 [-1/1] Matrix element 9 (1)
64- 69 F6.3 --- M10 [-1/1] Matrix element 10 (1)
71- 76 F6.3 --- M11 [-1/1] Matrix element 11 (1)
78- 83 F6.3 --- M12 [-1/1] Matrix element 12 (1)
85- 90 F6.3 --- M13 [-1/1] Matrix element 13 (1)
92- 97 F6.3 --- M14 [-1/1] Matrix element 14 (1)
99-104 F6.3 --- M15 [-1/1] Matrix element 15 (1)
106-111 F6.3 --- M16 [-1/1] Matrix element 16 (1)
113-118 F6.3 --- M17 [-1/1] Matrix element 17 (1)
120-125 F6.3 --- M18 [-1/1] Matrix element 18 (1)
127-132 F6.3 --- M19 [-1/1] Matrix element 19 (1)
134-139 F6.3 --- M20 [-1/1] Matrix element 20 (1)
141-146 F6.3 --- M21 [-1/1] Matrix element 21 (1)
148-153 F6.3 --- M22 [-1/1] Matrix element 22 (1)
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Note (1): Where the rp bin sizes for each matrix element are (Mpc/h):
0.115, 0.154, 0.205, 0.274, 0.365, 0.487, 0.649, 0.866, 1.155, 1.540,
2.054, 2.738, 3.652, 4.870, 6.494, 8.660, 11.548, 15.399, 20.535, 27.384,
36.517, and 48.697
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 24-Apr-2015