J/ApJ/869/145 A 3D Voronoi+Gapper galaxy cluster finder. II. (Campusano+, 2018)
A 3D Voronoi+Gapper galaxy cluster finder in redshift space to z∼0.2.
II. An abundant cluster population dominated by late-type galaxies unveiled.
Campusano L.E., Marinello G., Clowes R.G., Haines C.P., Pereira S.,
Pizarro D., Hitschfeld-Kahler N., Sochting I.K.
<Astrophys. J., 869, 145 (2018)>
=2018ApJ...869..145C 2018ApJ...869..145C
ADC_Keywords: Clusters, galaxy; Magnitudes, absolute; Redshifts;
Velocity dispersion
Keywords: cosmology: observations ; galaxies: clusters: general ;
large-scale structure of universe ; methods: data analysis
Abstract:
We identify 1901 galaxy clusters (Ng≥2) with the gapping-filtering
in radial velocity (VoML+G) algorithm (Paper I;
Campusano+ 2017ApJ...838..109P 2017ApJ...838..109P) on the two-Degree Field Galaxy
Redshift Survey (2dFGRS). We present the 341 clusters with at least 10
galaxies that are within 0.009<z<0.14 (the Catalog), of which 254
(∼75%) have counterparts in the literature (NED), with the remainder
(87) plausibly "new" because of incompleteness of previous searches or
unusual galaxy contents. The 207 clusters within z=0.04--0.09 are used
to study the properties of the galaxy systems in the nearby universe,
including their galaxy contents parameterized by the late-type galaxy
fractions (fL). For this nearly complete cluster subsample, we find
the following: (i) 63% are dominated by early-type galaxies (i.e., the
late-type-poor clusters, fL<0.5) with corresponding mean
multiplicity and logarithmic virial mass (in units of M☉) of
22±1 and 12.91±0.04, respectively; and (ii) 37% are dominated by
late-type galaxies (i.e., the late-type-rich clusters, fL≥0.5) with
corresponding mean multiplicity and logarithmic virial mass (in units
of M☉) of 15.7±0.9 and 12.66±0.07, respectively. The
statistical analysis of the late-type fraction distribution supports,
with a 3σ confidence level, the presence of two population
components. It is suggested that the late-type-poor galaxy systems
reflect and extend the class of Abell-APM-EDCC clusters and that the
late-type-rich systems (∼one-third of the total) belong to a new,
previously unappreciated class. The late-type-rich clusters, on
average high mass-to-light ratio systems, appear to be more clustered
on large scales than the late-type-poor clusters. A class of
late-type-rich clusters is not predicted by current theory.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 161 341 *VoML+G cluster catalog (Ng>10)
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Note on table2.dat: Voronoi-based, with a maximum likelihood
estimator plus a Gapper velocity filter (VoML+G; Paper I,
Campusano et al. 2017ApJ...838..109P 2017ApJ...838..109P)
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See also:
VII/110 : Rich clusters of galaxies (Abell+ 1989)
VII/175 : Edinburgh-Durham southern galaxy Cat. cluster Cat.(Lumsden+ 1992)
VII/226 : 2dF galaxy redshift survey 100k data release (2dFGRS Team, 2001)
VII/250 : The 2dF galaxy redshift survey (2dFGRS) (2dFGRS Team, 1998-2003)
J/MNRAS/289/263 : Galaxy clusters from the APM galaxy survey (Dalton+ 1997)
J/MNRAS/329/87 : 2dF galaxy redshift Survey (de Propris+,2002)
J/A+A/425/367 : REFLEX galaxy cluster survey catalogue (Boehringer+, 2004)
J/MNRAS/348/866 : 2dFGRS percolation-Inferred galaxy group (2PIGG) (Eke+,2004)
J/MNRAS/352/939 : 2dFGRS Wiener reconstruction of cosmic web (Erdogdu+, 2004)
J/AN/327/365 : Clusters and groups of galaxies in 2dF (Tago+, 2006)
J/A+A/520/A42 : Galaxy groups in the VIMOS-VLT Deep Survey (Cucciati+, 2010)
J/MNRAS/413/971 : Galaxy and mass assembly (GAMA) DR1 (Driver+, 2011)
J/MNRAS/418/2054 : Recession velocities fossil galaxy groups (Proctor+, 2011)
J/MNRAS/420/926 : Morphology of galaxies in WINGS clusters (Fasano+, 2012)
J/ApJ/751/50 : Galaxy groups from DEEP2 Redshift Survey (Gerke+ 2012)
J/A+A/588/A14 : Friends-of-friends galaxy group finder (Tempel+, 2016)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/341] Running sequence number
5- 16 F12.8 deg RAdeg [0.4/359.8] Right ascension (J2000)
18- 29 F12.8 deg DEdeg [-37/2.2] Declination (J2000)
31- 40 F10.8 --- z [0.01/0.14] Mean redshift
42- 44 I3 --- Ng [10/109] Number of member galaxies
46- 58 F13.8 km/s SigmaCZ [44/1477] Velocity dispersion
60- 69 F10.8 --- fLraw [0/0.93] Late-type galaxy fraction (initial)
71- 80 F10.8 --- fL [0/1] Late-type galaxy fraction (corrected)
82- 93 F12.8 mag MagMin [-23/-19] Minimum galaxy absolute
magnitude in the cluster
95-106 F12.8 mag MagMean [-20.7/-17] Mean galaxy absolute magnitude
in the cluster
108-109 I2 --- Nggal [1/69] Number of galaxies over absolute
magnitude limit
111-128 F18.16 --- Cz [0.5/0.97] Redshift completeness (Cz)
in the region (1)
130-159 A30 --- Name Name in NED search (2)
161-161 A1 --- Case [ab] VoML+G cluster detection case (a or b) (3)
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Note (1): The redshift completeness (Cz) is the ratio between the number of
galaxies with redshifts of quality Q≥3, within an area of interest,
and the respective number of galaxies in the parent catalog.
See section 2 for further details.
Note (2): NED correspondence with either clusters or groups of galaxies
(with the closest correspondence being listed when they were several)
as of 2018 July (see Section 5.2).
Note (3): Flag as follows:
a = the process converges to a system with at least two member
galaxies confined within an R200, or
b = at the start of the iteration the cylinder 0.5h-1Mpc in radius
contained at least five member galaxies.
See Section 3 for further explanations.
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History:
From electronic version of the journal
References:
Campusano et al. Paper I. 2017ApJ...838..109P 2017ApJ...838..109P
(End) Prepared by [AAS], Coralie FIX [CDS] 12-Nov-2019