J/MNRAS/348/866ivo://CDS.VizieR/J/MNRAS/348/866doi:10.26093/cds/vizier.73480866CDSEke V.R.Baugh C.M.Cole S.Frenk C.S.Norberg P.Peacock J.A.,Baldry I.K.Bland-Hawthorn J.Bridges T.Cannon R.Colless M.,Collins C.Couch W.Dalton G.De Propris R.Driver S.P.Efstathiou G.,Ellis R.S.Glazebrook K.Jackson C.Lahav O.Lewis I.Lumsden S.,Maddox S.Madgwick D.Peterson B.A.Sutherland W.Taylor K.2024-06-29T20:14:47Z2012-05-24T12:00:48ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxy-clustersredshiftedThe construction of a catalogue of galaxy groups from the Two-degree Field Galaxy Redshift Survey (2dFGRS) is described. Groups are identified by means of a friends-of-friends percolation algorithm which has been thoroughly tested on mock versions of the 2dFGRS generated from cosmological N-body simulations. The tests suggest that the algorithm groups all galaxies that it should be grouping, with an additional 40 per cent of interlopers. About 55 per cent of the ~190000 galaxies considered are placed into groups containing at least two members of which ~29000 are found. Of these, ~7000 contain at least four galaxies, and these groups have a median redshift of 0.11 and a median velocity dispersion of 260km/s. This 2dFGRS Percolation-Inferred Galaxy Group (2PIGG) catalogue represents the largest available homogeneous sample of galaxy groups.2004MNRAS.348..866Ehttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/348/866CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/250 : The 2dF Galaxy Redshift Survey (2dFGRS) (2dFGRS Team, 1998-2003)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/348/866https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/348/866http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/348/866https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/348/866https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/348/866http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/348/866GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/348/866/2dfngpga (Galaxies used for group-finding in the NGP)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/348/866/2dfngpga?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/348/866/2dfngpga?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/348/866/2dfngpga?GETtext/xml+votable180.050000true153.131335-3.8538450.005555555555555556Cone search capability for table J/MNRAS/348/866/2dfsgpga (Galaxies used for group-finding in the SGP)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/348/866/2dfsgpga?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/348/866/2dfsgpga?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/348/866/2dfsgpga?GETtext/xml+votable180.050000true3.61276-32.2705850.005555555555555556Cone search capability for table J/MNRAS/348/866/2dfngpgr (Group properties in the NGP)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/348/866/2dfngpgr?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/348/866/2dfngpgr?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/348/866/2dfngpgr?GETtext/xml+votable180.050000true165.642913-2.7760080.005555555555555556Cone search capability for table J/MNRAS/348/866/2dfsgpgr (Group properties in the SGP)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/348/866/2dfsgpgr?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/348/866/2dfsgpgr?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/348/866/2dfsgpgr?GETtext/xml+votable180.050000true2.400924-28.8605840.0055555555555555563/257-258 557-558 562 733-734 4/1027 1036 1040 1056 1599 1613 1615 1619-1620 1622 1624 1626 1635-1638 1640-1642 1677-1679 1681 1683-1686 1688-1690 1700-1701 2207 2223 2227 2236 2243-2244 2246-2247 2252 2272 2911 2930-2931 2940 2942 5/4103 4106-4107 4148 4152 4164 4168 4228 4230 4232-4234 6383 6389-6391 6394-6395 6451 6458-6459 6469-6471 6475 6484 6486 6500-6502 6508 6534-6535 6539 6556 6572 6576 6592 6687 6703 6707 6729-6731 6748 6764 6768 6788-6789 6791 6808-6809 6811-6812 6848 6912 8821-8823 8825 8827 8887 8891 8903 8907 8948 8952 8967 8969 8971 8980 8982-8983 9012 9014 9016 9092 9096 11256 11258-11259 11638-11639 11642-11643 11701 11703 11709 11711 11717 11719 11764-11766 12096-12097 12100-12101 12103 12112 6/16405-16407 16409-16411 16421-16423 16596 16598 16600 16602 16612-16613 16616 16660-16662 16664-16665 16676-16677 16680-16682 16916-16918 16924 16926 16940-16942 16944-16945 17024-17026 25471 25527 25531 25543 25549 25551 25554-25555 25570-25571 25573-25575 25723 25727 25783 25788-25789 25791 25829-25831 25893-25895 25897-25899 25942 25948-25950 25968-25970 26012-26014 26036-26038 26040-26042 26048-26050 26052-26053 26119 26127 26130 26133-26135 26147 26149-26151 26153-26155 26228-26230 26232-26234 26292-26294 26296-26298 26308-26310 26312-26314 26372-26374 26376-26378 26747 26811 26823 26827 26887 26893-26895 26913-26915 26996-26998 27000-27002 27060-27062 27064-27066 27076-27078 27080-27082 27160-27161 27163 27189 27241 27243 27252-27254 27256-27258 27332-27333 27396-27398 27400-27402 27652-27654 27656-27658 34554 35279 35305-35307 35539 35542-35543 35545 35547 35555 35558-35559 35561-35563 35605 35607 35610 35621-35623 35625 35627 35796 35800-35801 35812 35816 35818 35863 35867 35881 35883 35925-35927 36052-36053 36055 36060 36068 36070-36073 36076-36077 36098 36104 36130 36136 36138 36224 36226 36372 36376-36377 36388 36390 36392-36393 44983 44989-44991 45030-45031 46543 46547 46549-46551 46563 46565-46567 46711 46717-46718 46801-46803 46809 46865 46867 46873-46875 47068-47070 47088-47089 47096 47098 48213 48408-48409 48436-48437 48452-48454 48456-48458https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/348/866?format=asciiOpticaldefaultJ/MNRAS/348/866/2dfngpgaGalaxies used for group-finding in the NGPrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAradRight ascension in radians (1950 coordinates)degpos.eq.ra;meta.mainindexedDEradDeclination in radians (1950 coordinates)degpos.eq.dec;meta.mainindexedzRedshiftsrc.redshiftfloatbJmagb_J_ magnitudemagphot.mag;em.opt.BfloatbJmagllimiting b_J magnitude of the survey at the position of this galaxymagphot.magfloatnMean number density of galaxies in the survey at the position of this galaxyphys.densitydoubleWeight[1/4.4] Weight associated with this galaxyphys.atmol.weightfloatNgroup[0/16957] Group number to which this galaxy has been assigned (0 is ungrouped) (1)meta.number;phys.atmol.numberint_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)degpos.eq.decnullableindexedJ/MNRAS/348/866/2dfsgpgaGalaxies used for group-finding in the SGPrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAradRight ascension in radians (1950 coordinates)degpos.eq.ra;meta.mainindexedDEradDeclination in radians (1950 coordinates)degpos.eq.dec;meta.mainindexedzRedshiftsrc.redshiftfloatbJmagb_J_ magnitudemagphot.mag;em.opt.BfloatbJmagllimiting b_J magnitude of the survey at the position of this galaxymagphot.magfloatnMean number density of galaxies in the survey at the position of this galaxyphys.densitydoubleWeight[1/4.4] Weight associated with this galaxyphys.atmol.weightfloatNgroup[0/16957] Group number to which this galaxy has been assigned (0 is ungrouped) (1)meta.number;phys.atmol.numberint_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)degpos.eq.decnullableindexedJ/MNRAS/348/866/2dfngpgrGroup properties in the NGPrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNmemb[1/500] Unweighted number of membersmeta.numberintRAradRight ascension of group centre in radians (1950 coordinates)degpos.eq.ra;meta.mainDEradDeclination of group centre in radians (1950 coordinates)degpos.eq.dec;meta.mainzGroup redshiftsrc.redshiftfloatSeprms projected galaxy separation in Mpc/hMpcstat.stdev;pos.distance;instr.det.noisefloatsigmaGroup velocity dispersionkm/sphys.veloc.dispersionfloat_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)degpos.eq.decnullableindexedJ/MNRAS/348/866/2dfsgpgrGroup properties in the SGPrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNmemb[1/500] Unweighted number of membersmeta.numberintRAradRight ascension of group centre in radians (1950 coordinates)degpos.eq.ra;meta.mainDEradDeclination of group centre in radians (1950 coordinates)degpos.eq.dec;meta.mainzGroup redshiftsrc.redshiftfloatSeprms projected galaxy separation in Mpc/hMpcstat.stdev;pos.distance;instr.det.noisefloatsigmaGroup velocity dispersionkm/sphys.veloc.dispersionfloat_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)degpos.eq.decnullableindexed