J/ApJ/871/57 SDSS & MMT obs. of extremely massive QSOs & gal. (Yoon+, 2019)
Extremely massive quasars are not good proxies for dense environments compared
to massive galaxies: environments of extremely massive quasars and galaxies.
Yoon Y., Im M., Hyun M., David Jun H., Hwang N., Kim M., Park B.-G.
<Astrophys. J., 871, 57 (2019)>
=2019ApJ...871...57Y 2019ApJ...871...57Y
ADC_Keywords: QSOs; Galaxies, spectra; Redshifts; Photometry, SDSS;
Black holes
Keywords: galaxies: active ; galaxies: evolution ; galaxies: nuclei ;
quasars: supermassive black holes
Abstract:
Black hole mass scaling relations suggest that extremely massive black
holes (EMBHs) with MBH≳109.4M☉ are found in the most
massive galaxies with Mstar≳1011.6M☉, which are commonly
found in dense environments, like galaxy clusters. Therefore, one can
expect that there is a close connection between active EMBHs and dense
environments. Here, we study the environments of 9461 galaxies and
2943 quasars at 0.24≲z≲0.40, among which 52 are extremely massive
quasars with log(MBH/M☉)≥∼9.4, using Sloan Digital Sky Survey
and MMT Hectospec data. We find that, on average, both massive quasars
and massive galaxies reside in environments more than ∼2 times as
dense as those of their less massive counterparts with
log(MBH/M☉)≲9.0. However, massive quasars reside in
environments about ∼2 times less dense than inactive galaxies with
log(MBH/M☉)≥9.4, and only about one third of massive quasars
are found in galaxy clusters, while about two thirds of massive
galaxies reside in such clusters. This indicates that massive galaxies
are a much better signpost for galaxy clusters than massive quasars.
The prevalence of massive quasars in moderate to low density
environments is puzzling, considering that several simulation results
show that these quasars appear to prefer dense environments. Several
possible reasons for this discrepancy are discussed, although further
investigation is needed to obtain a definite explanation.
Description:
For three massive quasars (J135354.89+134228.5, J155846.72+223549.6,
and J170441.38+604430.5), we observed galaxies in the radius of
∼0.5deg from these quasars using the Hectospec on the MMT. The
Hectospec wavelength coverage is from ∼3700Å to ∼8500Å with a
spectral resolution of ∼6.2Å.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 72 52 Properties of extremely massive quasars
table2.dat 35 661 Galaxies observed by the MMT Hectospec
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See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
J/AJ/126/1720 : ugriz and Hα of double-peaked AGN (Strateva+, 2003)
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/678/635 : Spectroscopy of quasar binary candidates (Myers+, 2008)
J/ApJ/690/20 : Models of the AGN & black hole populations (Shankar+, 2009)
J/ApJ/708/137 : Broad-line AGNs in zCOSMOS survey (Merloni+, 2010)
J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)
J/ApJS/196/11 : Bulge+disk decompositions of SDSS galaxies (Simard+, 2011)
J/ApJ/734/68 : High redshift galaxy clusters in deep fields (Wen+, 2011)
J/ApJS/200/8 : AGES: the AGN and Galaxy Evolution Survey (Kochanek+, 2012)
J/ApJ/753/125 : NIR spectrosc. follow-up of 60 SDSS-DR7 QSOs (Shen+, 2012)
J/ApJS/199/34 : Clusters of galaxies in SDSS-III (Wen+, 2012)
J/MNRAS/436/34 : GALEX Arecibo SDSS survey. Final release (Catinella+, 2013)
J/ApJ/778/98 : Cross-correlation of SDSS QSOs & BOSS galaxies (Shen+, 2013)
J/ApJS/207/37 : IR sources spectroscopy in the AKARI NEP (Shim+, 2013)
J/MNRAS/441/1802 : Low-redshift QSOs in SDSS Stripe 82 (Karhunen+, 2014)
J/ApJS/210/3 : SDSS bulge, disk & total stellar masses (Mendel+, 2014)
J/ApJ/804/34 : Luminous AGNs and early-type SDSS galaxies (Hong+, 2015)
J/ApJ/806/109 : Rest-frame optical spectra of 3<z<6 QSOs (Jun+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- SDSS SDSS DR7 quasar name
(JHHMMSS.ss+DDMMSS.s) (1)
21- 26 F6.4 --- zspec [0.24/0.4] Spectroscopic redshifts (1)
28- 32 F5.2 [10-7J] logL5100 [44/45.8] Log of the 5100 continuum
luminosity; in units of erg/s
34- 38 F5.3 [10-7J] e_logL5100 [0/0.04] Uncertainty in logL5100
40- 44 I5 km/s FWHMHb [8162/38343] Hβ full width at half
maximum
46- 49 I4 km/s e_FWHMHb [154/8713] Uncertainty in FWHMHb
51- 55 F5.2 [Msun] logMBH [9.4/10.6] Log of black hole mass
57- 60 F4.2 [Msun] e_logMBH [0.01/0.4] Uncertainty in logMBH
62- 65 F4.1 --- d0.5Mpc [-1/10.2] Overdensity around quasar
at 0.5Mpc (2)
67- 70 F4.1 --- d7th [-0.6/19.1] Overdensity around quasar
at 7th nearest galaxy (2)
72 A1 --- DPE Double peaked Hβ emission? (Y=QSOs with
double-peaked broad Hβ lines;
30 occurrences) (3)
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Note (1): From Shen et al. (2011, J/ApJS/194/45)
Note (2): d0.5Mpc is the overdensity around a quasar measured in an aperture
with a radius of 0.5Mpc; d7th is the overdensity around a quasar
measured in an aperture whose radius corresponds to the projected
distance to the 7th nearest galaxy.
Note (3): See, Section 5.2.6 for classification of double-peaked
broad Hβ lines.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg [208/257.1] Right Ascension (J2000)
11- 18 F8.5 deg DEdeg [13.2/61.3] Declination (J2000)
20- 25 F6.4 --- zspec [0.07/1.5] MMT Hectospec spectroscopic redshift
27- 31 F5.2 mag rmag [17.8/21] SDSS r-band apparent (AB) magnitude
33- 35 A3 --- f_zspec Redshift Measurement Type (1)
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Note (1): In the last column, we mark "A" for objects whose redshifts were
measured by templates with absorption lines, while "E" was marked for
objects whose redshifts were measured by templates with emission lines.
We mark "A,E" for objects whose redshifts were measured by templates
with both absorption and emission lines.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 30-Jul-2020