J/MNRAS/305/259ivo://CDS.VizieR/J/MNRAS/305/259doi:10.26093/cds/vizier.73050259CDSWegner G.Colless M.Saglia R.P.McMahan R.K.JrDavies R.L.,Burstein D.Baggley G.2024-06-26T20:15:54Z1999-08-21T13:42:11ZCDS support team

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

cds-question@unistra.frgalaxiesspectroscopyredshiftedgalaxy-kinematicsWe present the spectroscopic data for the galaxies studied in the EFAR project, which is designed to measure the properties and peculiar motions of early-type galaxies in two distant regions. We have obtained 1319 spectra of 714 early-type galaxies over 33 observing runs on 10 different telescopes. We describe the observations and data reductions used to measure redshifts, velocity dispersions and the Mgb and Mg_2_ Lick linestrength indices. Detailed simulations and intercomparison of the large number of repeat observations lead to reliable error estimates for all quantities. The measurements from different observing runs are calibrated to a common zero-point or scale before being combined, yielding a total of 706 redshifts, 676 velocity dispersions, 676 Mgb linestrengths and 582 Mg_2_ linestrengths. The median estimated errors in the combined measurements are {Delta}cz=20km/s, {Delta}sigma/sigma=9.1%, {Delta}Mgb/Mgb=7.2% and {Delta}Mg_2_=0.015mag. Comparison of our measurements with published data sets shows no systematic errors in the redshifts or velocity dispersions, and only small zero-point corrections to bring our linestrengths on to the standard Lick system. We have assigned galaxies to physical clusters by examining the line-of-sight velocity distributions based on EFAR and ZCAT redshifts, together with the projected distributions on the sky. We derive mean redshifts and velocity dispersions for these clusters, which will be used in estimating distances and peculiar velocities and to test for trends in the galaxy population with cluster mass. The spectroscopic parameters presented here for 706 galaxies combine high-quality data, uniform reduction and measurement procedures, and detailed error analysis. They form the largest single set of velocity dispersions and linestrengths for early-type galaxies published to date.1999MNRAS.305..259Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/305/259CatalogResearchIsServedByTAP VizieR generic servicerelated-toVII/193 : The CfA Redshift Catalogue (ZCAT) (Huchra+ 1995)J/ApJS/106/1 : EFAR cluster and galaxy selection (Wegner+, 1996)J/MNRAS/292/499 : EFAR photometric data (Saglia+, 1997)J/MNRAS/321/277 : EFAR peculiar velocities (Colless+, 2001)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/305/259https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/305/259http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/305/259https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/305/259https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/305/259http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/305/259GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/MNRAS/305/259/table3Individual Spectroscopic MeasurementsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.intGINRUNSEQObservation identifierlongNameGalaxy namecharprimaryTelTelescope usedcharObsDateObservation datenullableQualQuality parametercharn_Qual[*] *: emission-line object with emission features listed in Notes columncharS/NSignal-to-noise ratiofloatcz? Redshiftkm/sintnullablee_cz? rms uncertainty on czkm/sintnullablesigma? Velocity dispersionkm/sintnullablee_sigma? rms uncertainty on sigmakm/sintnullableMgb? Mgb linestrength0.1nmfloatnullablee_Mgb? rms uncertainty on Mgb0.1nmfloatnullableMg2? Mg_2_ linestrengthmagfloatnullablee_Mg2? rms uncertainty on Mg2magfloatnullableNotesNotes (1)charJ/MNRAS/305/259/table5Spectroscopic parameters for the EFAR galaxiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.intGINGalaxy identification numberintNameGalaxy namecharprimaryCANCluster assignment numberintprimaryNspNumber of spectraintNczNumber of redshifts (1)intNsigmaNumber of dispersions (1)intNMgbNumber of Mgb linestrength (1)intNMg2Number of Mg2 linestrength (1)intczRedshift (combined estimate)km/sinte_czRedshift (total error)km/sintdcz? Redshift (weighted rms error)km/sintnullablesigma? Velocity dispersion (combined estimate)km/sintnullablee_sigma? Velocity dispersion (total error)km/sintnullabledsigma? Velocity dispersion (weighted rms error)km/sintnullableMgb? Mgb linestrength (combined estimate)0.1nmfloatnullablee_Mgb? Mgb linestrength (total error)0.1nmfloatnullabledMgb? Mgb linestrength (weighted rms error)0.1nmfloatnullableMg2? Mg_2_ linestrength (combined estimate)magfloatnullablee_Mg2? Mg_2_ linestrength (total error)magfloatnullabledMg2? Mg_2_ linestrength (weighted rms error)magfloatnullableS/NCombined signal-to-noise ratiofloatQualOverall quality parameter (1)charn_Qual[*] *: when galaxies possess emission linescharJ/MNRAS/305/259/table7Cluster mean redshifts and velocity dispersionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.intCANCluster assignment numberintprimaryN1Number of EFAR galaxiesint<cz>1EFAR average redshiftkm/sinte_<cz>1rms uncertainty on <cz>1km/sintsigma1? EFAR velocity dispersionkm/sintnullableN2Number of EFAR+ZCAT galaxiesint<cz>2EFAR+ZCAT average redshiftkm/sinte_<cz>2rms uncertainty on <cz>2km/sintsigma2? EFAR+ZCAT velocity dispersionkm/sintnullable