J/A+A/645/A97ivo://CDS.VizieR/J/A+A/645/A97doi:10.26093/cds/vizier.36450097CDSQuerejeta M.Lelli F.Schinnerer E.Colombo D.Lisenfeld U.,Mundell C.G.Bigiel F.Garcia-Burillo S.Herrera C.N.Hughes A.,Kruijssen J.M.D.Meidt S.Moore T.J.T.Pety J.Rigby A.J.2021-07-05T06:41:31Z2021-01-22T09:23:33ZCDS support team

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

cds-question@unistra.frgalaxiesmolecular-cloudsTidal dwarf galaxies (TDGs) are gravitationally bound condensations of gas and stars that formed during galaxy interactions. Here we present multi-configuration ALMA observations of J1023+1952, a TDG in the interacting system Arp 94, where we resolved CO(2-1) emission down to giant molecular clouds (GMCs) at 0.64" ~45pc resolution. We find a remarkably high fraction of extended molecular emission (~80-90%), which is filtered out by the interferometer and likely traces diffuse gas. We detect 111 GMCs that give a similar mass spectrum as those in the Milky Way and other nearby galaxies (a truncated power law with a slope of -1.76+/-0.13). We also study Larson's laws over the available dynamic range of GMC properties (~2dex in mass and ~1dex in size): GMCs follow the size-mass relation of the Milky Way, but their velocity dispersion is higher such that the size-linewidth and virial relations appear super-linear, deviating from the canonical values. The global molecular-to-atomic gas ratio is very high (~1) while the CO(2-1)/CO(1-0) ratio is quite low (~0.5), and both quantities vary from north to south. Star formation predominantly takes place in the south of the TDG, where we observe projected offsets between GMCs and young stellar clusters ranging from ~50pc to ~200pc; the largest offsets correspond to the oldest knots, as seen in other galaxies. In the quiescent north, we find more molecular clouds and a higher molecular-to-atomic gas ratio (~1.5); atomic and diffuse molecular gas also have a higher velocity dispersion there. Overall, the organisation of the molecular interstellar medium in this TDG is quite different from other types of galaxies on large scales, but the properties of GMCs seem fairly similar, pointing to near universality of the star-formation process on small scales.2021A&A...645A..97Qhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/645/A97CatalogResearchIsServedByTAP 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/A97https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/645/A97http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/645/A97https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/645/A97https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/645/A97http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/645/A97GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/645/A97/tablea3 (Measurements for Nyquist-sampled apertures)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/645/A97/tablea3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/645/A97/tablea3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/645/A97/tablea3?GETtext/xml+votable180.050000true155.860919.875070.005555555555555556Cone search capability for table J/A+A/645/A97/list (List of fits datacubes)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/645/A97/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/645/A97/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/645/A97/list?GETtext/xml+votable180.050000true155.8593619.866330.0055555555555555566/4439https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/645/A97?format=asciidefaultJ/A+A/645/A97/tablea3Measurements for Nyquist-sampled aperturesCloudID[1/111] Number of GMC from CPROPSmeta.idintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.maina/bGMC ellipse axis ratio (a/b)phys.angSize;arith.ratiofloatPAGMC ellipse position angledegpos.posAngfloatR? GMC radiuspcphys.size.radiusfloatnullablee_R? Uncertainty GMC radiuspcstat.errorfloatnullablesigmaVGMC velocity dispersionkm/sphys.veloc.dispersionfloate_sigmaVUncertainty GMC velocity dispersionkm/sstat.errorfloatTpeakGMC peak temperatureKphys.temperaturefloatLCOGMC CO luminosityK.km.s**-1.pc**2phys.luminosityinte_LCOUncertainty GMC CO luminosityK.km.s**-1.pc**2stat.errorintMlumGMC luminous masssolMassphys.massinte_MlumUncertainty GMC luminous masssolMassstat.errorintMvir? GMC virial masssolMassphys.massintnullablee_Mvir? Uncertainty GMC virial masssolMassstat.errorintnullableEnvironm[N/S] Environment in TDG: N=north, S=southmeta.notecharJ/A+A/645/A97/listList of fits datacubesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintNzNumber of slicesmeta.numberintObs.dateObservation datestime.epoch;obsnullablebVELOLower value of VELO intervalm/sphys.velocdoubleBVELOUpper value of VELO intervalm/sphys.velocdoubledVELOVELO resolutionm/sspect.resolutiondoublesizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitschar