J/A+A/645/A92ivo://CDS.VizieR/J/A+A/645/A92doi:10.26093/cds/vizier.36450092CDSMueller O.Fahrion K.Rejkuba M.Hilker M.Lelli F.Lutz K.,Pawlowski M.S.Coccato L.Anand G.S.Jerjen H.2021-09-10T09:10:33Z2021-01-19T07:17:42ZCDS support team

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

cds-question@unistra.frgalaxy-clustersgalaxiesDwarf spheroidal galaxies (dSphs) have been extensively investigated in the Local Group, but their low luminosity and surface brightness make similar work in more distant galaxy groups challenging. Modern instrumentation unlocks the possibility of scrutinizing these faint systems in other environments, expanding the parameter space of group properties. We use MUSE spectroscopy to study the properties of 14 known or suspected dSph satellites of Cen A. Twelve targets are confirmed to be group members based on their radial velocities. Two targets are background galaxies at ~50Mpc: KK 198 is a face-on spiral galaxy, and dw1315-45 is an ultra-diffuse galaxy with an effective radius of ~2300pc. The 12 confirmed dSph members of the Cen A group have old and metal-poor stellar populations and follow the stellar metallicity-luminosity relation defined by the dwarf galaxies in the Local Group. In the three brightest dwarf galaxies (KK 197, KKs 55, and KKs 58), we identify globular clusters, as well as a planetary nebula in KK197, although its association with this galaxy and/or the extended halo of Cen A is uncertain. Using four discrete tracers, we measure the velocity dispersion and dynamical mass of KK197. This dSph appears dark matter dominated and lies on the radial acceleration relation of star-forming galaxies within the uncertainties. It also is consistent with predictions stemming from modified Newtonian dynamics (MOND). Surprisingly, in the dwarf KK203 we find an extended H ring. Careful examination of Hubble Space Telescope photometry reveals a very low level of star formation at ages between 30-300Myr. The H{alpha} emission is most likely linked to a ~40Myr old supernova remnant, although other possibilities for its origin cannot be entirely ruled out.2021A&A...645A..92Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/645/A92CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/645/A92https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/645/A92http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/645/A92https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/645/A92https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/645/A92http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/645/A92GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/645/A92/table1 (Observation summary for the 14 dwarf galaxy candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/645/A92/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/645/A92/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/645/A92/table1?GETtext/xml+votable180.050000true198.187917-41.8319440.005555555555555556Cone search capability for table J/A+A/645/A92/list (List of fits datacubes)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/645/A92/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/645/A92/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/645/A92/list?GETtext/xml+votable180.050000true198.18825-41.832860.0055555555555555566/43254 43256 43425 43427 43604 43607 43610 43613 43796 43832 43921https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/645/A92?format=asciidefaultJ/A+A/645/A92/table1Observation summary for the 14 dwarf galaxy candidatesSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameNamemeta.id;meta.maincharRAJ2000Center of observation right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Center of observation declination (J2000)pos.eq.dec;meta.mainDateObserving datetime.epochcharNexpNumber of exposuresmeta.numberintExptimeIntegration time per exposurestime.epoch;obs.exposureintAMAverage airmass during observationobs.airMassfloatIQAverage image quality (seeing)arcsecinstr.obsty.seeingfloatS/N? Measured signal-to-noise ratio on the stacked cube between 6600 and 6800{AA} (see text)stat.snrfloatnullableNoteNotemeta.notecharJ/A+A/645/A92/listList of fits datacubesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameNamemeta.id;meta.maincharRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainscaleScale of the imagearcsec/pixinstr.scalefloatNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintNzNumber of slicesmeta.numberintbAWAVLower value of AWAV interval0.1nmem.wlfloatBAWAVUpper value of AWAV interval0.1nmem.wlfloatdAWAVAWAV resolution0.1nmpos.angResolutionfloatsizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitschar