J/MNRAS/500/1003 Redshifts for galaxies in the HSC-SSP and unWISE (Wen+, 2021)
Photometric redshifts for galaxies in the Subaru Hyper Suprime-Cam and unWISE
and a catalogue of identified clusters of galaxies.
Wen Z.L., Han J.L.
<Mon. Not. R. Astron. Soc., 500, 1003-1017 (2021)>
=2021MNRAS.500.1003W 2021MNRAS.500.1003W (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies ; Photometry, ugriz ;
Photometry, infrared ; Redshifts
Keywords: catalogues - galaxies: clusters: general -
galaxies: distances and redshifts
Abstract:
We first present a catalogue of photometric redshifts for 14.68
million galaxies derived from the 7-band photometric data of Hyper
Suprime-Cam Subaru Strategic Program and the Wide-field Infrared
Survey Explorer using the nearest-neighbour algorithm. The redshift
uncertainty is about 0.024 for galaxies of z=<0.7, and steadily
increases with redshift to about 0.11 at z∼2. From such a large data
set, we identify 21661 clusters of galaxies, among which 5537 clusters
have redshifts z>1 and 642 clusters have z>1.5, significantly
enlarging the high redshift sample of galaxy clusters. Cluster
richness and mass are estimated, and these clusters have an equivalent
mass of M500≥0.7x1014M☉. We find that the stellar mass of
the brightest cluster galaxies (BCGs) in each richness bin does not
significantly evolve with redshift. The fraction of star-forming BCGs
increases with redshift, but does not depend on cluster mass.
Description:
Based on large data set of photometric surveys, the photometric
redshift of galaxies is a fundamental parameter for many further
studies, such as galaxy evolution, structure formation, and cluster
identification. We cross-match the galaxy catalogue of the HSC-SSP and
the source catalogue of the unWISE to get a 7-band spectral energy
distribution (SED) for the common galaxies in the two catalogues. The
photometric redshift of a galaxy can thus be estimated by the
comparison with a spectroscopic training sample in colour space. In
addition, the stellar mass of galaxies is another important parameter
in the algorithm for cluster identification, and can be estimated from
the photometric data.
The HSC-SSP carries out the optical photometric survey in five
broad-bands (grizy) and three narrow bands (NB387, NB816, and NB921;
Aihara et al. 2018PASJ...70S...4A 2018PASJ...70S...4A). It is currently the deepest
large-area optical survey, and consists of three layers of survey
depth.
The WISE survey observed the whole sky in four mid-infrared bands
(Wright et al. 2010AJ....140.1868W 2010AJ....140.1868W): W1 (3.4µm), W2 (4.6µm), W3
(12µm), and W4 (22µm). The unWISE catalogue was presented for
about 2 billion sources from the unblurred coadds of 5-yr NEOWISE
single-exposure images (Lang 2014AJ....147..108L 2014AJ....147..108L; Schlafly et al.
2019ApJS..240...30S 2019ApJS..240...30S, Cat. II/363).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 103 21661 The 21661 clusters of galaxies identified from
the HSC-SSP x unWISE data
table2.dat 141 372974 The member candidates of 372974 galaxies for
21661 identified clusters from the
HSC-SSP x unWISE data
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See also:
II/363 : The band-merged unWISE Catalog (Schlafly+, 2019)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- IDcl [1/21661] Internal cluster identifier
7- 25 A19 --- Name Cluster name (WH JHHMMSS.s+DDMMSS)
27- 35 F9.5 deg RAdeg Right ascension (J2000) of the BCG (1)
37- 44 F8.5 deg DEdeg Declination (J2000) of the BCG (1)
46- 51 F6.4 --- z Redshift of the cluster
53- 58 F6.3 mag imag i-band magnitude of the BCG (AB system)
(1)
60- 65 F6.3 mag W1mag W1-band magnitude of the BCG (AB system)
(1)
67- 71 F5.2 --- S/N Signal to noise ratio
73- 77 F5.3 Mpc r500 Cluster radius
79- 84 F6.2 --- lambda500 Cluster richness
86- 90 F5.2 10+14Msun M500 Dervied cluster mass
92- 94 I3 --- Ngal Number of member galaxy candidates
within r500
96- 103 A8 --- Ref Reference for previously known clusters
(2)
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Note (1): Properties of the brightest cluster galaxy
Note (2): Reference as follows:
WH11 = Wen & Han 2011ApJ...734...68W 2011ApJ...734...68W, Cat. J/ApJ/734/68
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)
CAMIRA14 = Oguri 2014MNRAS.444..147O 2014MNRAS.444..147O, Cat. J/MNRAS/444/147
CAMIRA18 = Oguri et al. 2018PASJ...70S..20O 2018PASJ...70S..20O, Cat. J/PASJ/70/S20
WH18 = Wen & Han 2018MNRAS.481.4158W 2018MNRAS.481.4158W, Cat. J/MNRAS/481/4158
XXL = Adami et al. 2018A&A...620A...5A 2018A&A...620A...5A
ACT = Hilton et al. 2018ApJS..235...20H 2018ApJS..235...20H
MaDCoWS = Gonzalez et al. 2019ApJS..240...33G 2019ApJS..240...33G, Cat. J/ApJS/240/33
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- IDcl [1/21661] Internal cluster identifier
7- 15 F9.5 deg RAdeg Right ascension (J2000) of member galaxy
candidate
17- 24 F8.5 deg DEdeg Declination (J2000) of member galaxy
candidate
26- 31 F6.4 --- zph Photometric redshift of the galaxy
33- 38 F6.3 mag gmag ?=99 HSC-ssp g-band magnitude
40- 45 F6.3 mag e_gmag ?=99 Error on gmag
47- 52 F6.3 mag rmag ?=99 HSC-ssp r-band magnitude
54- 59 F6.3 mag e_rmag ?=99 Error on rmag
61- 66 F6.3 mag imag ?=99 HSC-ssp i-band magnitude
68- 73 F6.3 mag e_imag ?=99 Error on imag
75- 80 F6.3 mag zmag ?=99 HSC-ssp z-band magnitude
82- 87 F6.3 mag e_zmag ?=99 Error on zmag
89- 94 F6.3 mag ymag ?=99 HSC-ssp y-band magnitude
96- 101 F6.3 mag e_ymag ?=99 Error on ymag
103- 108 F6.3 mag W1mag ?=99 WISE W1 (3.4um) band magnitude
110- 114 F5.3 mag e_W1mag ?=99 Error on W1mag
116- 121 F6.3 mag W2mag ?=99 WISE W2 (4.6um) band magnitude
123- 128 F6.3 mag e_W2mag ?=99 Error on W2mag
130- 135 F6.3 [Msun] logMass Logarithm of galaxy stellar mass
137- 141 F5.3 Mpc rp Projected distance to the cluster centre
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 28-Sep-2023