J/A+A/486/85ivo://CDS.VizieR/J/A+A/486/85doi:10.26093/cds/vizier.34860085CDSChilingarian I.V.Cayatte V.Durret F.Adami C.Balkowski C.,Chemin L.Lagana T.F.Prugniel P.2017-07-03T14:25:47Z2008-12-16T17:53:40ZCDS support team

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

cds-question@unistra.frgalaxy-clustersgalaxiesphotometryThe morphology and stellar populations of low-luminosity early-type galaxies in clusters have until now been limited to a few relatively nearby clusters such as Virgo or Fornax. Scenarii for the formation and evolution of dwarf galaxies in clusters are therefore not well constrained. We investigate here the morphology and stellar populations of low-luminosity galaxies in the relaxed richness class 1 cluster Abell 496 (z=0.0330). Deep multiband imaging obtained with the CFHT Megacam allowed us to select a sample of faint galaxies, defined here as objects with magnitudes 18<r'<22mag within a 1.2arcsec fibre (-18.8<MB<-15.1mag). We observed 118 galaxies spectroscopically with the ESO VLT FLAMES/Giraffe spectrograph with a resolving power R=6300. We present structural analysis and colour maps for the 48 galaxies belonging to the cluster. We fit the spectra of 46 objects with PEGASE. HR synthetic spectra to estimate the ages, metallicities, and velocity dispersions. We estimated possible biases by similarly analysing spectra of ~1200 early-type galaxies from the Sloan Digital Sky Survey Data Release 6 (SDSS DR6). We computed values of {alpha}/Fe abundance ratios from the measurements of Lick indices. We briefly discuss effects of the fixed aperture size on the measurements.2008A&A...486...85Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/486/85CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+AS/139/525 : Abell 496 heliocentric velocities (Durret+, 1999)J/A+AS/139/559 : Abell 496 photometric catalogue (Slezak+, 1999)J/A+AS/140/155 : Abell 496 gri photometry (Moretti+, 1999)J/A+A/393/439 : Catalogue of galaxies towards Abell 496 (Durret+, 2002)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/486/85https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/486/85http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/486/85https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/486/85https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/486/85http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/486/85GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/486/85/tablea (Data for galaxies in Abell 496)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/486/85/tablea?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/486/85/tablea?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/486/85/tablea?GETtext/xml+votable180.050000true68.2790417-13.21077780.0055555555555555566/22577https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/486/85?format=asciiOpticaldefaultJ/A+A/486/85/tableaData for galaxies in Abell 496e_Fe5335? rms uncertainty on Fe53350.1nmstat.errorfloatnullableFe5406? F35406 Lick index0.1nmmeta.code;spect.indexfloatnullablee_Fe5406? rms uncertainty on Fe54060.1nmstat.errorfloatnullable[Mg/Fe]? Abundance [Mg/Fe]phys.abundfloatnullablee_[Mg/Fe]? rms uncertainty on [Mg/Fe]stat.error;phys.abundfloatnullable_RARight ascension (derived from ACO496) for Eq=J2000degpos.eq.ra;meta.main_DEDeclination (derived from ACO496) for Eq=J2000degpos.eq.dec;meta.mainComCommentsmeta.notecharSpTSpectral typesrccharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[CCD2008]Sequential number (G1)meta.recordcharACO496ACO496 designation (JHHMMSS.ss+DDMMSS.s)meta.idcharBMAGAbsolute B magnitudemagphys.magAbs;em.opt.BfloatembStr? Embedded structuresmeta.code;src.morphcharu*magTotal u* magnitudemagphot.mag;em.opt.Ufloate_u*magrms uncertainty on u*magmagstat.error;phot.mag;em.opt.Ufloatg'magTotal g' magnitudemagphot.mag;em.opt.Bfloate_g'magrms uncertainty on g'magmagstat.error;phot.mag;em.opt.Bfloatr'magTotal r' magnitudemagphot.mag;em.opt.Rfloate_r'magrms uncertainty on r'magmagstat.error;phot.mag;em.opt.Rfloati'magTotal i' magnitudemagphot.mag;em.opt.Ifloate_i'magrms uncertainty on i'magmagstat.error;phot.mag;em.opt.IfloatDprojProjected distance from central cD galaxyarcsecpos.angDistanceintDVVelocity difference (RV-V(A496))km/sphys.veloc;arith.diffintreffEffective radiusarcsecphys.angSizefloate_reffrms uncertainty on reffarcsecstat.errorfloat<mueff>Mean effective surface brightness in B within 1reffmag.arcsec**-2phot.mag.sb;em.opt.Bfloate_<mueff>rms uncertainty on <mueff>mag.arcsec**-2stat.errorfloatRVRadial velocitykm/sspect.dopplerVeloc;pos.heliocentricinte_RVrms uncertainty on RVkm/sstat.errorintsigma? Best-fitting velocity dispersionkm/sphys.veloc.dispersionintnullablee_sigma? rms uncertainty on sigmakm/sstat.errorintnullabletau? Best-fitting SSP-equivalent ageGyrtime.agefloatnullablee_tau? rms uncertainty on tGyrstat.errorfloatnullableZ? Best-fitting metallicityphys.abund.Zfloatnullablee_Z? rms uncertainty on Zstat.error;src.redshiftfloatnullableNote[a] Note (1)meta.notecharFe5015? Fe5015 Lick index0.1nmmeta.code;spect.indexfloatnullablee_Fe5015? rms uncertainty on Fe50150.1nmstat.errorfloatnullableMgB? MgB Lick index0.1nmspect.indexfloatnullablee_MgB? rms uncertainty on MgB0.1nmstat.errorfloatnullableFe5270? Fe5270 Lick index0.1nmmeta.code;spect.indexfloatnullablee_Fe5270? rms uncertainty on Fe52700.1nmstat.errorfloatnullableFe5335? Fe5335 Lick index0.1nmmeta.code;spect.indexfloatnullable