J/MNRAS/513/3946 Clusters of galaxies from DES*unWISE data (Wen+, 2022)
Clusters of galaxies up to z = 1.5 identified from photometric data of the Dark
Energy Survey and unWISE.
Wen Z.L., Han J.L.
<Mon. Not. R. Astron. Soc. 513, 3946-3959 (2022)>
=2022MNRAS.513.3946W 2022MNRAS.513.3946W (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies ; Clusters, galaxy ; Photometry ; Optical ; Infrared ;
Positional data ; Redshifts
Keywords: catalogues - galaxies: clusters: general -
galaxies: distances and redshifts
Abstract:
Using photometric data from the Dark Energy Survey and the Wide-field
Infrared Survey Explorer, we estimate photometric redshifts for 105
million galaxies using the nearest-neighbour algorithm. From such a
large data base, 151244 clusters of galaxies are identified in the
redshift range of 0.1 < z ≤ 1.5 based on the overdensity of the total
stellar mass of galaxies within a given photometric redshift slice,
among which 76826 clusters are newly identified and 30477 clusters
have a redshift z > 1. We cross-match these clusters with those in the
catalogues identified from the X-ray surveys and the
Sunyaev-Zel'dovich (SZ) effect by the Planck, South Pole Telescope and
Atacama Cosmology Telescope surveys, and get the redshifts for 45
X-ray clusters and 56 SZ clusters. More than 95 per cent SZ clusters
in the sky region have counterparts in our catalogue. We find multiple
optical clusters in the line of sight towards about 15 per cent of SZ
clusters.
Description:
In this paper, we combine the DES optical data with the mid-infrared
data from the Wide-field Infrared Survey Explorer to identify clusters
of galaxies. Identification of galaxy clusters requires a large number
of galaxies with known redshifts. The photometric redshifts can be
used for the purpose, and can be estimated from photometric data. In
addition, stellar masses of galaxies can be derived based on the
mid-infrared luminosity of galaxies, which is useful to identify
density peaks, (see Introduction section).
The DES made photometric observations at five broad optical bands
(grizy), covering the southern Galactic cap of ∼5000 deg2. The
survey reaches a 10σ depth of i ∼ 24 (AB magnitude) for point
sources. The median full width at half-maximum of the point spread
function is 0.88 arcsec in the i-band. From the latest public DES data
release 2 (DR2; Abbott et al. 2021ApJS..255...20A 2021ApJS..255...20A, Cat. II/371), we
get 399 million galaxies detected above 5σ in at least one band
and with the magnitudes at least in the r, i, and z bands. The WISE
observed the whole sky at four mid-infrared bands of W1, W2, W3, and
W4. We use the W1 and W2-band data from the five-year coadd image
data, named as unWISE, which is deep enough to detect massive galaxies
up to a redshift of z ∼ 2 (Schlafly et al. 2019ApJS..240...30S 2019ApJS..240...30S, Cat.
II/363). The unWISE catalogue contains 208 million sources with
W1-band data available in the sky coverage of the DES DR2, (i.e
section 2. Photometric data of galaxies). The closest source within
this radius is adopted for the targeted object. The such matched 105
million objects are named as DES*unWISE galaxies in this paper.
From the DES*unWISE galaxies with estimated redshifts, we find 151244
clusters as listed in table1.dat with their basis properties, among
which 76826 clusters are newly identified and 74418 clusters are
previously known (i.e see 3 Clusters identified from the DES*unWISE
galaxies). Next as section 4 and subsection 4.3 Comparison with SZ
clusters explain, indentified clusters using the SZ effect from the
SPT and ACT survey data are used to found multiple optical clusters
along a line of sight due to the projection effect. Specifically, we
regroup optical clusters as counterpart in the line of sight towards
an SZ cluster if it is located within a projected distance of r500
towards 155 SPT clusters and 236 ACT clusters respectively as listed
in tablea3.dat with their basis properties, IDs and positions.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 105 151244 The clusters of galaxies identified from
the DES*unWISE galaxies
tablea3.dat 97 853 Multiple optical clusters in the line of sight
towards 155 SPT clusters and 236 ACT clusters
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See also:
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16)
(Ahumada+, 2020)
J/A+A/609/A84 : VIPERS spectroscopic redshifts (PDR-2) (Scodeggio+, 2018)
J/A+A/559/A14 : VIMOS VLT Deep Survey final data release (Le Fevre+, 2013)
J/ApJS/225/27 : 3D-HST Survey: grism spectra master catalog
(Momcheva+, 2016)
II/363 : The band-merged unWISE Catalog (Schlafly+, 2019)
II/371 : The Dark Energy Survey (DES): Data Release 2 (Abbott+, 2021)
J/MNRAS/500/1003 : Redshifts for galaxies in the HSC-SSP and unWISE
(Wen+, 2021)
J/ApJS/253/3 : Sunyaev-Zel'dovich galaxy clusters surveyed by ACT
(Hilton+, 2021)
J/ApJS/253/56 : Galaxy clusters from the DESI surveys. I. (Zou+, 2021)
J/ApJS/216/27 : Galaxy clusters discovered in the SPT-SZ survey
(Bleem+, 2015)
J/ApJS/199/34 : Clusters of galaxies in SDSS-III (Wen+, 2012)
J/ApJ/807/178 : Newly rich galaxy clusters identified in SDSS-DR12
(Wen+, 2015)
J/MNRAS/475/343 : 2MASS, WISE, and SuperCOSMOS clusters of galaxies
(Wen+, 2018)
J/ApJS/224/1 : redMaPPer cluster catalog from DES data (Rykoff+, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- ID Identifier cluster's number (ID)
8- 26 A19 --- Name Cluster's name (Name)
28- 36 F9.5 deg RAdeg Right ascension of the BCG (J2000) (RA)
38- 46 F9.5 deg DEdeg Declination of the BCG (J2000) (Dec)
48- 53 F6.4 --- z Estimated photometric redshift to be the
median value of the photometric
redshifts of member galaxy candidates
see section 2 and 3 (zcl)
55- 60 F6.3 mag imag The i-band DES apparent AB magnitude of
the BCG (iBCG)
62- 67 F6.3 mag W1mag The W1 WISE apparent AB magnitude of the
BCG (W1BCG)
69- 73 F5.2 --- SNR SNR for cluster detection (SNR)
75- 79 F5.3 Mpc r500 Cluster radius r500 (r500) (1)
81- 86 F6.2 --- lambda500 Cluster's richness (λ500) (2)
88- 91 F4.2 10+14Msun M500 Derived cluster mass within the volume
defined by r500 (M500)
93- 95 I3 --- Ngal Number of member galaxy candidates
within r500 (Ngal)
97- 105 A9 --- Ref Reference for previously known clusters
in our sample (Othercatalogues) (3)
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Note (1): Radius around the center of a galaxy cluster within which the average
mass density is 500 times the critical density of the universe at the
cluster's redshift (is estimated from a calibrated
r500-mstellar,r1 relation based on a sample of X-ray clusters
Wen & Han 2021MNRAS.500.1003W 2021MNRAS.500.1003W, Cat. J/MNRAS/500/1003).
Note (2): Then, the total stellar mass within the estimated radius r500 is
calculated from the galaxy data, which is later defined as the
richness of a cluster, λ500, as in Wen & Han (Wen & Han
2021MNRAS.500.1003W 2021MNRAS.500.1003W, Cat. J/MNRAS/500/1003) as
M*500(1+z)0.21/M*stellar with M*stellar = 4*1010 M☉.
Note (3): For the 74418 previously known clusters, the references catalogs are
as follows:
ACT = Atacama Cosmology Telescope,
Hilton et al. 2021ApJS..253....3H 2021ApJS..253....3H, Cat. J/ApJS/253/3, 621
clusters in our sample
CFSFDP = Clustering by Fast Search and Find of Density Peaks,
Zou et al. 2021ApJS..253...56Z 2021ApJS..253...56Z, Cat. J/ApJS/253/56, 19088
clusters in our sample
RASS = ROSAT All-Sky Survey, Klein et al. 2019MNRAS.488..739K 2019MNRAS.488..739K,
Cat. J/MNRAS/488/739, 520 clusters in our sample
SPT = South Pole Telescope survey data,
Bleem et al. 2015ApJS..216...27B 2015ApJS..216...27B, Cat. J/ApJS/216/27,
Bleem et al. 2020ApJS..247...25B 2020ApJS..247...25B, Cat; J/ApJS/247/25,
Huang et al. 2020AJ....159..110H 2020AJ....159..110H, 741 clusters in our
sample
WH21 = Wen & Han 2021MNRAS.500.1003W 2021MNRAS.500.1003W, Cat. J/MNRAS/500/1003,
2346 clusters in our sample
WHL = Wen et al. 2012ApJS..199...34W 2012ApJS..199...34W, Cat. J/ApJS/199/34,
Wen & Han 2015ApJ...807..178W 2015ApJ...807..178W, Cat. J/ApJ/807/178, 6344
clusters in our sample
WHY18 = Wen et al. 2018MNRAS.475..343W 2018MNRAS.475..343W, Cat. J/MNRAS/475/343, i
3652 clusters in our sample
WaZP = Wavelet Z Photometric algorithm identifier,
Aguena et al. 2021MNRAS.502.4435A 2021MNRAS.502.4435A, 4950 clusters in our
sample
Y21 = Extended halo-based group finder,
Yang et al. 2021ApJ...909..143Y 2021ApJ...909..143Y, 31024 clusters in our
sample
redMaPPer = red-sequence matched-filter Probabilistic Percolation
cluster finder, Rykoff et al. 2016ApJS..224....1R 2016ApJS..224....1R,
Cat. J/ApJS/224/1, 5132 clusters in our sample
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Byte-by-byte Description of file: tablea3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 A18 --- SZName SZ cluster name (SZclustername)
20 I1 --- IDrel Relative identifier ID number to the
optical clusters in the line of sight
towards the SZ cluster (IDrel)
22- 27 I6 --- ID Identifier optical cluster's number
29- 36 F8.4 deg RASZdeg Right ascension of SZ cluster (J2000)
(RASZ)
38- 45 F8.4 deg DESZdeg Declination of SZ cluster (J2000) (DECSZ)
47- 51 F5.2 --- SNR The significance SNR of the SZ detection
(SNR)
53- 58 F6.4 --- zSZ Redshift of SZ cluster (zSZ)
60- 68 F9.5 deg RAdeg Right ascension of the BCG optical cluster
(J2000) (RA)
70- 78 F9.5 deg DEdeg Declination of the BCG optical cluster
(J2000) (Dec)
80- 85 F6.4 --- z Redshift of the optical cluster (zc)
87- 92 F6.2 --- lambda500 Cluster richness estimated from the stellar
mass (λ500) (1)
94- 97 F4.2 arcmin Theta Angular distance between SZ and optical
positions (Θ)
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Note (1): Then, the total stellar mass within the estimated radius r500 is
calculated from the galaxy data, which is later defined as the
richness of a cluster, λ500, as in Wen & Han (Wen & Han
2021MNRAS.500.1003W 2021MNRAS.500.1003W, Cat. J/MNRAS/500/1003) as
M*500(1+z)0.21/M*stellar with M*stellar = 4*1010 M☉.
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History:
From electronic version of the journal
(End) Luc Trabelsi [CDS] 09-Jan-2025