J/A+A/327/952ivo://CDS.VizieR/J/A+A/327/952doi:10.26093/cds/vizier.33270952CDSStein P.Jerjen H.Federspiel M.2013-02-27T06:34:08Z1998-04-01T10:27:54ZCDS support team

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

cds-question@unistra.frgalaxy-clustersradial-velocityBased on the photometric survey of the inner region of the Centaurus cluster (Jerjen & Dressler, 1997, Cat. <J/A+AS/124/1>) we measured redshifts for a deep, surface brightness limited sample of galaxies using the MEFOS multifibre spectrograph at the ESO 3.6m telescope. With the new data set radial velocities for 120 centrally located cluster members become available which is equivalent to 78% of all known cluster galaxies in the region brighter than B_T_=18.5. The relevant aspect of this investigation is that new redshifts for 32 dwarf galaxies have been measured, rising the total number to 48. We investigate the prominent bimodal velocity distribution of Centaurus in more detail, discussing the very different characteristics of the velocity distributions for the main Hubble types E&S0, spirals, Im&BCD, and dE&dS0. The nucleated, bright dwarf ellipticals are the only galaxies with a Gaussian-like distribution centred at 3148+/-98km/s. The remarkable coincidence of this velocity with the mean velocity of Cen 30 and the redshift of NGC 4696 in particular strongly suggests a connection of the dE&dS0s to the gravitational centre of the Centaurus cluster and/or to the cluster dominant E galaxy. The application of statistical tests reveals the existence of a population dwarf galaxies bound to NGC 4696. The dynamical parameters for the two velocity components suggest that Cen 30 is the real Centaurus cluster whereas Cen 45 can only be a loosely bound group of galaxies. This conclusion is followed up with a type-mixture analysis. All results are fully consistent with the cluster-group scenario. Whether Cen 45 is merging with the cluster or is located in the close background remains unclear. We show that the poorness of Cen 45 represents an intrinsic problem which makes it difficult to approach this question.1997A&A...327..952Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/327/952CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+AS/124/1 : The Centaurus Cluster Catalogue (Jerjen+ 1997)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/327/952https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/327/952http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/327/952https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/327/952https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/327/952http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/327/952GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/327/952/table5a (New redshifts for Centaurus cluster members)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/327/952/table5a?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/327/952/table5a?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/327/952/table5a?GETtext/xml+votable180.050000true191.8760956-41.65034220.005555555555555556Cone search capability for table J/A+A/327/952/table5b (New redshifts of background galaxies)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/327/952/table5b?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/327/952/table5b?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/327/952/table5b?GETtext/xml+votable180.050000true191.9435499-41.21833120.005555555555555556Cone search capability for table J/A+A/327/952/table5c (Reobserved redshifts for Centaurus cluster members)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/327/952/table5c?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/327/952/table5c?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/327/952/table5c?GETtext/xml+votable180.050000true191.8822878-41.26227980.0055555555555555566/43625-43628 43630 43713https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/327/952?format=asciiOpticaldefaultJ/A+A/327/952/table5aNew redshifts for Centaurus cluster membersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqSequential numbermeta.id;meta.mainintRA1950Right ascension (1950.0)pos.eq.ra;meta.mainDE1950Declination (1950.0)pos.eq.dec;meta.mainCCCCentaurus Cluster Catalogue (Jerjen & Dressler 1996, Cat. <J/A+AS/124/1>) reference numbermeta.idintMtypeMorphological typesrc.morph.typecharBTTotal blue magnitudemagphot.mag;em.opt.BfloatSBeff? Effective surface brightnessmag.arcsec**-2phot.mag.sbfloatnullableProb? Cen 45 cluster member probability (1)%statfloatnullableVcc? Cross-correlation redshiftkm/sphys.veloc;pos.heliocentricintnullablee_Vcc? rms uncertainty on Vcckm/sstat.errorintnullableVem? Emission line redshiftkm/ssrc.redshift;spect.lineintnullablee_Vem? rms uncertainty on Vemkm/sstat.errorintnullablecz? Heliocentric radial velocity (2)km/sspect.dopplerVeloc;pos.heliocentricintnullablee_cz? rms uncertainty on czkm/sstat.errorintnullable_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)pos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)pos.eq.decnullableindexedJ/A+A/327/952/table5bNew redshifts of background galaxiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqSequential numbermeta.idintRA1950Right ascension (1950.0)pos.eq.ra;meta.mainDE1950Declination (1950.0)pos.eq.dec;meta.mainCCCCentaurus Cluster Catalogue (Jerjen & Dressler 1996, Cat. <J/A+AS/124/1>) reference numbermeta.idintMtypeMorphological typesrc.morph.typecharBTTotal blue magnitudemagphot.mag;em.opt.BfloatSBeff? Effective surface brightnessmag.arcsec**-2phot.mag.sbfloatnullableProb? Cen 45 cluster member probability (1)%statfloatnullableVcc? Cross-correlation redshiftkm/sphys.veloc;pos.heliocentricintnullablee_Vcc? rms uncertainty on Vcckm/sstat.errorintnullableVem? Emission line redshiftkm/sphys.veloc;pos.heliocentricintnullablee_Vem? rms uncertainty on Vemkm/sstat.errorintnullablecz? Heliocentric radial velocity (2)km/sspect.dopplerVeloc;pos.heliocentricintnullablee_cz? rms uncertainty on czkm/sstat.errorintnullable_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)pos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)pos.eq.decnullableindexedJ/A+A/327/952/table5cReobserved redshifts for Centaurus cluster membersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqSequential numbermeta.idintRA1950Right ascension (1950.0)pos.eq.ra;meta.mainDE1950Declination (1950.0)pos.eq.dec;meta.mainCCCCentaurus Cluster Catalogue (Jerjen & Dressler 1996, Cat. <J/A+AS/124/1>) reference numbermeta.idintMtypeMorphological typesrc.morph.typecharBTTotal blue magnitudemagphot.mag;em.opt.BfloatSBeff? Effective surface brightnessmag.arcsec**-2phot.mag.sbfloatnullableProb? Cen 45 cluster member probability (1)%statfloatnullableVcc? Cross-correlation redshiftkm/sphys.veloc;pos.heliocentricintnullablee_Vcc? rms uncertainty on Vcckm/sstat.errorintnullableVem? Emission line redshiftkm/sphys.veloc;pos.heliocentricintnullablee_Vem? rms uncertainty on Vemkm/sstat.errorintnullablecz? Heliocentric radial velocity (2)km/sspect.dopplerVeloc;pos.heliocentricintnullablee_cz? rms uncertainty on czkm/sstat.errorintnullable_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)pos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)pos.eq.decnullableindexed