J/ApJ/920/74 Galaxy Environment of Extremely Massive Quasars. I. (Jun+, 2021)
The Galaxy Environment of Extremely Massive Quasars.
I. An Overdensity of Hα emitters at z=1.47
Jun H.D., Im M., Hyun M., Yoon Y., Eisenhardt P.R.M., Hong J., Jeon Y.,
Kim D.,Kim J.-W.,Kim Ji H.,Park C.
<Astrophys. J., 920, 74 (2021)>
=2021ApJ...920...74J 2021ApJ...920...74J
ADC_Keywords: Clusters, galaxy; QSOs; Black holes; Photometry, infrared
Keywords: Galaxy groups ; Protoclusters ; Supermassive black holes ;
Quasars
Abstract:
We measure a strong excess in the galaxy number density around
PG1630+377, an extremely massive (MBH∼109.7M☉) quasar at z=1.475,
using near-infrared narrowband imaging. We identify 79 narrow H-band
excess objects in a 525arcmin2 area including the vicinity and
surroundings of the quasar. These sources are likely Hα line
emitting, star-forming galaxies at z∼1.47. We detect a
δ=6.6±2.7 overdensity of narrow H-band excess objects
located at a projected distance ∼2.1Mpc northeast of the quasar, which
is the densest region in the target area. The overdensity is present
in BzK color-selected galaxies, while a previously reported
overdensity in the immediate vicinity of PG1630+377 is not, and yet
appears as a group-like structure. These megaparsec-scale environments
are estimated to merge into a ∼1014.7M☉ cluster at present. Our
results support the view that extremely massive black holes form and
grow in group-scale environments and later incorporate into a galaxy
cluster.
Description:
We performed the imaging observations with the United Kingdom Infrared
Telescope (UKIRT) Wide Field Camera (WFCAM) over 2011 June to 2013
January, in clear weather conditions. WFCAM has four sparsely spaced
2kx2k NIR detectors with a detector gap of 12.8' and each array
covering a field of view 13.65x13.65'. We observed with the NBH and
H bands to detect an excess in the NBH over H, as well as with the J
and K bands for color information. The total exposure times were 40,
60, 200, and 42minutes in the J, H, NBH , and K bands, respectively.
Objects:
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RA (ICRS) DE Designation(s)
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16 32 01.11 +37 37 49.9 PG1630+377 = QSO B1630+3744
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 106 79 H-alpha emitter properties
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See also:
II/207 : Palomar-Green catalog UV-excess stellar objects (Green+ 1986)
VII/289 : SDSS quasar catalog, sixteenth data release (DR16Q) (Lyke+, 2020)
J/ApJS/162/1 : MUSYC; optical source catalog (Gawiser+, 2006)
J/AJ/132/1275 : CIRS (Cluster Infall Regions in the SDSS). I. (Rines+, 2006)
J/ApJ/654/115 : DEEP2 Galaxy Redshift Survey; SDSS QSOs (Coil+, 2007)
J/ApJ/662/808 : Cusp radius in luminous elliptical galaxies (Lauer+, 2007)
J/ApJ/677/169 : Hα galaxies at z=0.84 (Villar+, 2008)
J/ApJ/708/137 : Broad-line AGNs in zCOSMOS survey (Merloni+, 2010)
J/MNRAS/416/2041 : Hα emitters at z=2.23 (Matsuda+, 2011)
J/ApJ/765/87 : Chandra observations of 2QZ Cluster 1004+00 (Lehmer+, 2013)
J/MNRAS/428/1128 : UDS/COSMOS HiZELS galaxies (Sobral+, 2013)
J/ApJ/795/158 : The MASSIVE survey ; 116 candidate galaxies (Ma+, 2014)
J/ApJ/804/34 : Luminous AGNs and early-type SDSS galaxies (Hong+, 2015)
J/MNRAS/451/2303 : CF-HiZELS survey (Sobral+, 2015)
J/ApJ/859/38 : HST grism obs. of CARLA galaxy cluster cand. (Noirot+, 2018)
J/ApJS/243/24 : The CASBaH galaxy redshift survey (Prochaska+, 2019)
J/ApJ/871/57 : SDSS & MMT obs. extremely massive QSOs & gal. (Yoon+, 2019)
J/ApJS/249/17 : SDSS QSO DR14 spectral properties (Rakshit+, 2020)
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 [1/79] Sequential item number
4- 4 I1 --- Det [1/3] UKIRT WFCAM Detector (1)
6- 14 F9.5 deg RAdeg [247/249] Right Ascension (J2000)
16- 23 F8.5 deg DEdeg [37/38] Declination (J2000)
25- 29 F5.2 mag Hmag [15.8/23.3] Hband (broad-band) AB magnitude (2)
31- 34 F4.2 mag e_Hmag [0/0.4] Uncertainty in Hmag (2)
36- 40 F5.2 mag NBHmag [14.9/22.1] Narrow-band H-band AB magnitude (2)
42- 45 F4.2 mag e_NBHmag [0/0.3] Uncertainty in NBHmag (2)
47- 50 F4.2 mag H-NBH [0.19/1.51] Hmag-NBHmag, broad-narrow color (3)
52- 55 F4.2 mag e_H-NBH [0/0.4] Uncertainty in (H-NBH) (3)
57- 61 F5.2 mag Jmag [15.9/26.1] Jband (broad-band) AB magnitude (2)
63- 66 F4.2 mag e_Jmag [0/3] Uncertainty in Jmag (2)
68- 72 F5.2 mag Kmag [16.1/23.3] Kband (broad-band) AB magnitude (2)
74- 77 F4.2 mag e_Kmag [0.01/0.3] Uncertainty in Kmag (2)
79- 83 F5.1 --- Sigma-NBH [2.5/319] Significance NBH emission; Equation 1
85- 87 I3 0.1nm EW-Ha [17/366] Rest-frame line equivalent width (4)
89- 90 I2 0.1nm e_EW-Ha [0/84] Uncertainty in EW-Ha (4)
92- 96 F5.2 10-7W LogLHa [42/44.9] Hα luminosity from the NBH
excess flux (5)
98-101 F4.2 10-7W e_LogLHa [0/0.2] Uncertainty in LogLHa (5)
103-106 F4.1 --- delta [-0.7/5.9] Overdensity of neighbor galaxies (6)
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Note (1): UKIRT WFCAM Detector as follows:
1 = SW to the quasar (22 occurrences)
2 = S to the quasar (22 occurrences)
3 = contains the quasar (35 occurrences)
Note (2): Uncorrected for aperture size.
Note (3): Corrected to the effective wavelength of the NBH-band and with filter
correction between the broad and narrow bands.
Note (4): Assume the redshifted Hα emission lies on the center of the
NBH filter; See Equation 2.
Note (5): Hα luminosity from the NBH excess flux (FNBH) with aperture
correction and [NII] contamination correction; See Equation 2.
Note (6): Interloper-corrected overdensity of neighbor galaxies within a Mpc
projected distance; Equation 3.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 10-Feb-2023