J/A+A/296/643ivo://CDS.VizieR/J/A+A/296/643doi:10.26093/cds/vizier.32960643CDSKarachentsev I.D.Karachentseva V.E.Richter G.M.Vennik J.A.1997-12-09T16:27:40Z1997-12-09T17:27:36ZCDS support team

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

cds-question@unistra.frgalaxy-clustersgalaxiesphotometryUsing the prime focus of the 6-meter telescope, we have searched for low surface brightness dwarf galaxies in two regions in the Coma cluster: one in the center of the cluster and the other one 40arcmin to the west. The observations were carried out with a total exposure time 4x5x600sec and with a 1.2arcsec seeing. Our survey is complete down to V=25.5 and R=25.0mag. The central field shows an excess of faint galaxies (121 versus 104 in the reference field) significant at a one sigma level only. However, the central-field excess is mainly caused by the presence of faint (V=24/25mag), neutral colour (V-R=0.3/0.4) objects of low surface brightness, SB=26.0/26.5mag/arcsec^2^. These characteristics are quite consistent with those of the dwSph's in the Local Group which have typically M_v_~10mag and A~1kpc. The observed excess corresponds to a surface number density of 4gal/arcmin^2^ in the center of Coma, thus implying a total population of cluster dwarfs of ~4000 down to the limiting absolute magnitude -10mag. The number ratio of LSBD's to normal galaxies (with M<-18mag for normals) in Coma turns out to be 20:1. Such ratio is comparable to that observed in other rich clusters: A3574 (14:1) and A1367 (6:1), but is much larger than the 2:1 ratio obtained for moderate nearby clusters such as Virgo, Fornax, Antlia.1995A&A...296..643Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/296/643CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/296/643https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/296/643http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/296/643https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/296/643https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/296/643http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/296/643GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/296/643/table1Properties of galaxies in the central Coma fieldNoteNotes (1)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDGalaxy identification numbermeta.id;meta.mainintVmagApparent total V magnitudemagphot.mag;em.opt.VfloatRmagApparent total R magnitudemagphot.mag;em.opt.RfloatDiamVAngular diameter measured on V framearcsecphys.angSize;srcfloatDiamRAngular diameter measured on R framearcsecphys.angSize;srcfloatSBVAverage surface brightness within DiamVmag/arcsecphot.mag.sbfloatSBRAverage surface brightness within DiamRmag/arcsecphot.mag.sbfloatV-RTotal V-R color indexmagphot.color;em.opt.V;em.opt.RfloatJ/A+A/296/643/table2Properties of galaxies in the reference fieldrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDGalaxy identification numbermeta.id;meta.mainintVmagApparent total V magnitudemagphot.mag;em.opt.VfloatRmagApparent total R magnitudemagphot.mag;em.opt.RfloatDiamVAngular diameter measured on V framearcsecphys.angSize;srcfloatDiamRAngular diameter measured on R framearcsecphys.angSize;srcfloatSBVAverage surface brightness within DiamVmag/arcsecphot.mag.sbfloatSBRAverage surface brightness within DiamRmag/arcsecphot.mag.sbfloatV-RTotal V-R color indexmagphot.color;em.opt.V;em.opt.RfloatNoteNotes (1)meta.notechar