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. =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 (N_g_>=2) with the gapping-filtering in radial velocity (VoML+G) algorithm (Paper I; Campusano+ 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=0.5) with corresponding mean multiplicity and logarithmic virial mass (in units of M_{sun}_) of 15.7+/-0.9 and 12.66+/-0.07, respectively. The statistical analysis of the late-type fraction distribution supports, with a 3{sigma} 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: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table2.dat 161 341 *VoML+G cluster catalog (N_g_>10) -------------------------------------------------------------------------------- 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) -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 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 (C_z_) 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) -------------------------------------------------------------------------------- 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 R_200_, or b = at the start of the iteration the cylinder 0.5h^-1^Mpc in radius contained at least five member galaxies. See Section 3 for further explanations. -------------------------------------------------------------------------------- History: From electronic version of the journal References: Campusano et al. Paper I. 2017ApJ...838..109P ================================================================================ (End) Prepared by [AAS], Coralie FIX [CDS] 12-Nov-2019