J/ApJ/751/46ivo://CDS.VizieR/J/ApJ/751/46doi:10.26093/cds/vizier.17510046CDSKirby E.N.Cohen J.G.Bellazzini M.2014-02-15T15:01:52Z2014-01-29T12:25:54ZCDS support team

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

cds-question@unistra.frgalaxiesradial-velocitymetallicityline-intensitiesinfrared-photometryvisible-astronomybroad-band-photometryVV124 (UGC 4879) is an isolated, dwarf irregular/dwarf spheroidal (dIrr/dSph) transition-type galaxy at a distance of 1.36 Mpc. Previous low-resolution spectroscopy yielded inconsistent radial velocities for different components of the galaxy, and photometry hinted at the presence of a stellar disk. In order to quantify the stellar dynamics, we observed individual red giants in VV124 with the Keck/Deep Extragalactic Imaging Multi-Object Spectrograph (DEIMOS). We validated members based on their positions in the color-magnitude diagram, radial velocities, and spectral features. Our sample contains 67 members. The average radial velocity is <v_r_>=-29.1+/-1.3km/s in agreement with the previous radio measurements of H I gas. The velocity distribution is Gaussian, indicating that VV124 is supported primarily by velocity dispersion inside a radius of 1.5 kpc. Outside that radius, our measurements provide only an upper limit of 8.6km/s on any rotation in the photometric disk-like feature. The velocity dispersion is {sigma}_v_=9.4+/-1.0km/s, from which we inferred a mass of M_1/2_=(2.1 +/-0.2)x10^7^M_{sun}_ and a mass-to-light ratio of (M/L_V_)_1/2_=5.2+/-1.1M_{sun}_/L_{sun}_, both measured within the half-light radius. Thus, VV124 contains dark matter. We also measured the metallicity distribution from neutral iron lines. The average metallicity, <[Fe/H]>=-1.14+/-0.06, is consistent with the mass-metallicity relation defined by dSph galaxies. The dynamics and metallicity distribution of VV124 appear similar to dSphs of similar stellar mass.2012ApJ...751...46Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/751/46CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/144/4 : Dwarf galaxies in the Local Group (McConnachie+, 2012)J/A+A/533/A37 : VI HST photometry of VV124 = UGC4879 (Bellazzini+, 2011)J/ApJS/191/352 : Milky Way dwarf satellites abundances (Kirby+, 2010)J/ApJ/705/328 : Abundance measurements in Sculptor dSph (Kirby+, 2009)J/ApJ/682/1217 : Abundances in red giants in 7 globular clusters (Kirby+, 2008)J/ApJ/659/162 : CAS parameters of 199 nearby galaxies (Taylor-Mager+, 2007)J/MNRAS/380/281 : Faint galactic satellites spectro. survey (Martin+, 2007)J/PASP/117/227 : Properties of 101 galaxies from the NFGS (Kewley+, 2005)J/ApJ/630/784 : UBVR observations of nearby galaxies (Taylor+, 2005)J/A+A/414/23 : CCD H{alpha} and R photometry of 334 galaxies (James+, 2004)J/ApJS/149/327 : JKs photometry of local universe galaxies (Grauer+, 2003)J/ApJ/543/178 : Nearby Optical Galaxy (NOG) sample (Giuricin+, 2000)J/ApJS/126/331 : Spectrophotometry of nearby field galaxies (Jansen+ 2000)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/751/46https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/751/46http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/751/46https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/751/46https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/751/46http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/751/46GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/751/46/table2 (Target list (from erratum in 2013,ApJ,768,96))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/751/46/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/751/46/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/751/46/table2?GETtext/xml+votable180.050000true138.7952.8311110.0055555555555555566/7265https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/751/46?format=asciiOpticalInfrareddefaultJ/ApJ/751/46/table2Target list (from erratum in 2013,ApJ,768,96)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1167/17428] Object identification from Bellazzini et al. 2011A&A...527A..58Bmeta.id;meta.mainintRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.maingmag[19/26] LBT g band magnitudemagphot.mag;em.opt.Bfloate_gmag[0.003/0.06] Uncertainty in gmagmagstat.error;phot.mag;em.opt.Bfloatrmag[18/24] LBT r band magnitudemagphot.mag;em.opt.Rfloate_rmag[0.004/0.06] Uncertainty in rmagmagstat.error;phot.mag;em.opt.RfloatN[1/2] Number of DEIMOS masks on which the object was observedmeta.numberintSNR[2/134] Signal-to-noise ratio per Angstrom ({AA})0.1nm**-1stat.snrfloatHRV[-194/52]? Heliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloatnullablee_HRV[2/14]? Uncertainty in HRVkm/sstat.errorfloatnullableEWNa[0.2/4.2]? NaI8190 doublet equivalent width ({AA}) in Angstroms0.1nmspect.line.eqWidthfloatnullablee_EWNa[0.02/0.4]? Uncertainty in EWNa ({AA})0.1nmstat.errorfloatnullable[Fe/H][-3/-0.05]? Logarithmic iron abundance relative to the Sunlog(Sun)phys.abund.Fefloatnullablee_[Fe/H][0.2/0.5]? Uncertainty in [Fe/H]log(Sun)stat.error;phys.abund.FefloatnullableMm[N/Y] Object considered to be member of VV124?meta.code.membercharn_MmReason(s) object considered to be non-member (1)meta.notecharB11Cross-match with Bellazzini et al., 2011, Cat. J/A+A/533/A37, within 0.5"meta.ref.urlintnullable