J/ApJ/923/143 HectoMAP Cluster Survey: clusters & BCGs (Sohn+, 2021)
The HectoMAP Cluster Survey: spectroscopically identified clusters and their
brightest cluster galaxies (BCGs).
Sohn J., Geller M.J., Hwang Ho S., Diaferio A., Rines K.J., Utsumi Y.
<Astrophys. J., 923, 143 (2021)>
=2021ApJ...923..143S 2021ApJ...923..143S
ADC_Keywords: Clusters, galaxy; Redshifts; Velocity dispersion; Surveys;
Spectra, optical; Magnitudes, absolute; Galaxies, spectra; Colors
Keywords: Redshift surveys ; Galaxy clusters ; Brightest cluster galaxies ;
Large-scale structure of the universe
Abstract:
We apply a friends-of-friends (FoF) algorithm to identify galaxy
clusters and we use the catalog to explore the evolutionary synergy
between brightest cluster galaxies (BCGs) and their host clusters. We
base the cluster catalog on the dense HectoMAP redshift survey
(2000 redshifts deg-2). The HectoMAP FoF catalog includes
346 clusters with 10 or more spectroscopic members within the range
0.05<z<0.55 and with a median z=0.29. We list these clusters and their
members. We also include central velocity dispersions (σ*,BCG)
for the FoF cluster BCGs, a distinctive feature of the HectoMAP FoF
catalog. HectoMAP clusters with higher galaxy number density (80
systems) are all genuine clusters with a strong concentration and a
prominent BCG in Subaru/Hyper Suprime-Cam images. The phase-space
diagrams show the expected elongation along the line of sight.
Lower-density systems include some low reliability systems. We
establish a connection between BCGs and their host clusters by
demonstrating that σ*,BCG/σcl decreases as a function
of cluster velocity dispersion (σcl), in contrast, numerical
simulations predict a constant σ*,BCG/σcl. Sets of
clusters at two different redshifts show that BCG evolution in massive
systems is slow over the redshift range z<0.4. The data strongly
suggest that minor mergers may play an important role in BCG evolution
in clusters with σcl<300km/s. For lower mass systems
(σcl<300km/s), major mergers may play a significant role. The
coordinated evolution of BCGs and their host clusters provides an
interesting test of simulations in high-density regions of the
universe.
Description:
The Sloan Digital Sky Survey (SDSS) DR16 (Ahumada+ 2020, V/154) is the
photometric basis of HectoMAP. See Section 2.1.
The HectoMAP spectroscopy comes from two major spectroscopic surveys:
SDSS/BOSS (Baryon Oscillation Spectroscopic Survey) and our own
Multi-Mirror Telescope (MMT)/Hectospec survey. We first compiled the
SDSS DR16 spectroscopy which includes 25524 SDSS and BOSS redshifts
within the HectoMAP field. The typical redshift uncertainty of these
SDSS/BOSS measurements is ∼36km/s. The Hectospec survey was carried
out from 2009-2019. See Section 2.2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 63 346 FoF clusters in HectoMAP
table2.dat 64 5992 HectoMAP FoF cluster members
table3.dat 62 346 BCGs of in the HectoMAP FoF clusters
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See also:
VII/4 : Abell and Zwicky Clusters of Galaxies (Abell+ 1974)
VII/86 : Groups of Galaxies. I. Nearby Groups (Huchra+ 1982)
VII/110 : Rich Clusters of Galaxies (Abell+ 1989)
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)
J/AJ/113/483 : Groups of Galaxies (Ramella+ 1997)
J/MNRAS/301/881 : The ROSAT brightest cluster sample - I. (Ebeling+, 1998)
J/ApJS/129/435 : NORAS galaxy cluster survey. I. (Bohringer+, 2000)
J/MNRAS/337/256 : Galaxy in low X-ray luminosity clusters (Balogh+, 2002)
J/MNRAS/348/866 : 2dFGRS Percolation-Inferred Galaxy Group (2PIGG) (Eke+, 2004)
J/AJ/127/1811 : Catalog of SDSS compact groups of galaxies (Lee+, 2004)
J/ApJS/167/1 : Galaxy groups and clusters from SDSS (Berlind+, 2006)
J/ApJS/183/197 : Galaxy clusters identified from the SDSS-DR6 (Wen+, 2009)
J/ApJS/191/254 : GMBCG galaxy cluster catalog from SDSS DR7 (Hao+, 2010)
J/A+A/514/A102 : SDSS DR7 groups of galaxies (Tago+, 2010)
J/ApJ/746/178 : The augmented maxBCG cluster catalog (Rykoff+, 2012)
J/A+A/540/A106 : SDSS-DR8 groups and clusters of galaxies (Tempel+, 2012)
J/ApJ/767/15 : Hectospec Cluster Survey (HeCS) (Rines+, 2013)
J/MNRAS/444/147 : Richness of galaxy clusters (Oguri, 2014)
J/ApJ/785/104 : redMaPPer. I. Algorithm applied to SDSS DR8 (Rykoff+, 2014)
J/A+A/566/A1 : Flux- & volume-limited groups for SDSS gal. (Tempel+, 2014)
J/ApJS/216/27 : Galaxy clusters discovered in SPT-SZ survey (Bleem+, 2015)
J/A+A/581/A41 : OmegaWINGS BV phot. of galaxy clusters (Gullieuszik+, 2015)
J/ApJS/224/1 : redMaPPer cluster catalog from DES data (Rykoff+, 2016)
J/ApJS/225/23 : Compact groups of gal. from SDSS-DR12 (MLCG) (Sohn+, 2016)
J/A+A/588/A14 : Friends-of-friends galaxy group finder (Tempel+, 2016)
J/AJ/153/220 : NORAS II. I. First results (Bohringer+, 2017)
J/ApJS/229/20 : MMT/Hectospec redshift survey for Abell 2029 (Sohn+, 2017)
J/PASJ/70/S20 : HSC Wide S16A cluster catalog (Oguri+, 2018)
J/ApJ/862/172 : HeCS-red: Hectospec surveys of redMaPPer cl. (Rines+, 2018)
J/ApJ/855/100 : The HectoMAP cluster survey. II. X-ray clusters (Sohn+, 2018)
J/ApJ/856/172 : The HectoMAP cluster survey. I. (Sohn+, 2018)
J/ApJS/240/33 : MaDCoWS. I. Catalog of z∼1 galaxy clusters (Gonzalez+, 2019)
J/ApJ/871/129 : A redshift catalog of the galaxy cluster A2029 (Sohn+, 2019)
J/ApJ/891/129 : The HeCS-omnibus catalog: SDSS & MMT sp. obs. (Sohn+, 2020)
J/ApJ/909/129 : HectoMAP redshift survey DR1 (Sohn+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [HMRM]
5- 7 I03 --- HMRM [1/346] HectoMAP FoF Cluster ID
9- 18 F10.6 deg RAdeg [200.3/249.7] Right Ascension (J2000)
20- 28 F9.6 deg DEdeg [42.5/44] Declination (J2000)
30- 37 F8.6 --- z [0.059/0.55] Central cluster redshift
39- 41 I3 --- Nmem [10/146] Number of FoF cluster members
43- 45 I3 --- Nsp [10/302] Number of spectroscopically
identified members (1)
47- 50 I4 km/s vdisp [97/1019] Velocity dispersion
52- 54 I3 km/s e_vdisp [19/245] Velocity dispersion error
56- 59 F4.2 --- Density [0.04/0.34] Galaxy number density
61- 61 A1 --- Den [HL] Density regime flag (2)
63- 63 A1 --- BCG [YN] Brightest cluster member flag (Y=central
galaxy is the brightest cluster member)
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Note (1): Number of spectroscopically identified members fainter than
rMAG=-19.72
Note (2): Density regime flag as follows:
H = high-density regime (80 occurrences);
L = low-density regime (266 occurrences).
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [HMRM]
5- 7 I03 --- HMRM [1/346] HectoMAP FoF Cluster ID
9- 27 I19 --- OBJID SDSS DR16 Object ID
29- 38 F10.6 deg RAdeg [200.27/249.7] Right Ascension (J2000)
40- 48 F9.6 deg DEdeg [42.5/44] Declination (J2000)
50- 56 F7.5 --- zspec [0.059/0.55] Spectroscopic redshift
58- 64 F7.5 --- e_zspec [1e-5/0.0006]? Redshift error
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [HMRM]
5- 7 I03 --- HMRM [1/346] HectoMAP FoF Cluster ID
9- 27 I19 --- OBJID SDSS DR16 Object ID
29- 34 F6.2 mag rMag [-25.6/-20.7] r-band absolute magnitude
36- 39 F4.2 mag e_rMag [0.01/2] r-band absolute magnitude error
41- 44 F4.2 --- g-r [0.4/9.85] g-r color index
46- 49 F4.2 --- Dn4000 [1.1/4.64] Dn4000 age index (1)
51- 54 F4.2 --- e_Dn4000 [0.01/0.6]? Dn4000 error (NULL value="Inf")
56- 58 I3 km/s vdisp [97/597]?=-99 Stellar velocity dispersion
60- 62 I3 km/s e_vdisp [5/89]?=-99 Stellar velocity dispersion error
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Note (1): The Dn4000 index, a stellar population age indicator (e.g.,
Kauffmann+ (2003MNRAS.341...33K 2003MNRAS.341...33K)). Following the definition from
Balogh+ (1999ApJ...527...54B 1999ApJ...527...54B), we compute the flux ratio between
4000-4100Å and 3850-3950Å:
Dn4000=Fλ(4000-4100)/Fλ(3850-3950).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 19-May-2023