J/ApJ/496/39ivo://CDS.VizieR/J/ApJ/496/39doi:10.26093/cds/vizier.14960039CDSZabludoff A.I.Mulchaey J.S.1998-09-19T16:38:41Z1998-09-19T16:38:34ZCDS support team

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

cds-question@unistra.frgalaxy-clustersradial-velocityWe use multifiber spectroscopy of 12 poor groups of galaxies to address (1) whether the groups are bound systems or chance projections of galaxies along the line of sight; (2) why the members of each group have not already merged to form a single galaxy, despite the groups' high galaxy densities, short crossing times, and likely environments for galaxy-galaxy mergers; and (3) how galaxies might evolve in these groups, where the collisional effects of the intragroup gas and the tidal influences of the global potential are weaker than in rich clusters. Each of the 12 groups has fewer than about five cataloged members in the literature. Our sample consists of 1002 galaxy velocities, 280 of which are group members. The groups have mean recessional velocities between 1600 and 7600km/s. Nine groups, including three Hickson compact groups, have the extended X-ray emission characteristic of an intragroup medium (see Paper II, 1998ApJ...496...73M).1998ApJ...496...39Zhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/496/39CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/496/39https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/496/39http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/496/39https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/496/39https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/496/39http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/496/39GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/496/39/table1 (Galaxy data)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/496/39/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/496/39/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/496/39/table1?GETtext/xml+votable180.050000true20.6491671.8908330.005555555555555556Cone search capability for table J/ApJ/496/39/table2 (Group kinematic properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/496/39/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/496/39/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/496/39/table2?GETtext/xml+votable180.050000true21.371251.8047220.005555555555555556https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/496/39?format=asciiOpticaldefaultJ/ApJ/496/39/table1Galaxy datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameGalaxy namemeta.id;meta.maincharRAJ2000Right ascension (J2000.0)pos.eq.ra;meta.mainDEJ2000Declination signpos.eq.dec;meta.mainHRVHeliocentric radial velocity (1)km/sphys.veloc;pos.heliocentricinte_HRVrms uncertainty on HRVkm/sstat.errorintLine[0/2] Type of measurement (2)meta.codeintMType[ES] Morphological type (3)src.morph.typecharPlate[pc] Plate/CCD (4)obs.fieldcharr_HRV[N0] Heliocentric radial velocity reference (5)meta.refcharJ/ApJ/496/39/table2Group kinematic propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGroupGroup namemeta.id;meta.maincharRAJ2000Right ascension of the group optical projected centroid in J2000pos.eq.ra;meta.mainDEJ2000Declination signpos.eq.dec;meta.mainNtotTotal number of galaxies with measured redshifts in the fiber fieldmeta.numberintNgroupNumber of group membersmeta.numberintHRVBiweight estimators of the mean heliocentric velocitykm/sphys.veloc;pos.heliocentricinte_HRVrms uncertainty on HRVkm/sstat.errorintsigmaLine-of-sight velocity dispersionkm/sphys.veloc.dispersionintE_sigmaError on sigma (upper limit)km/sstat.errorinte_sigmaError on sigma (lower limit)km/sstat.errorintrsamplePhysical radius of the group sampled by the fiber field (h^-1^Mpc)Mpcphys.size.radiusfloatrp? Pair radius (h^-1^Mpc)Mpcphys.size.radiusfloatnullablerh? Mean harmonic (virial )radius (h^-1^Mpc)Mpcphys.size.radiusfloatnullableMvir? Virial mass (h^-1^Mpc)solMassphys.massfloatnullabletc/tH? Ratio of the crossing time to Hubble timetime.crossingfloatnullable