J/ApJ/772/107ivo://CDS.VizieR/J/ApJ/772/107doi:10.26093/cds/vizier.17720107CDSDonovan Meyer J.Koda J.Momose R.Mooney T.Egusa F.Carty M.,Kennicutt R.Kuno N.Rebolledo D.Sawada T.Scoville N.Wong T.2017-09-19T14:24:13Z2015-03-09T12:52:09ZCDS support team

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

cds-question@unistra.frgalaxiesmolecular-cloudsradio-astronomygalaxy-kinematicsWe resolve 182 individual giant molecular clouds (GMCs) larger than 2.5x10^5^M_{sun}_ in the inner disks of 5 large nearby spiral galaxies (NGC 2403, NGC 3031, NGC 4736, NGC 4826, and NGC 6946) to create the largest such sample of extragalactic GMCs within galaxies analogous to the Milky Way. Using a conservatively chosen sample of GMCs most likely to adhere to the virial assumption, we measure cloud sizes, velocity dispersions, and ^12^CO(J=1-0) luminosities and calculate cloud virial masses. The average conversion factor from CO flux to H_2_ mass (or X_CO_) for each galaxy is 1-2x10^20^/cm2 (K.km/s)^-1^, all within a factor of two of the Milky Way disk value (~2x10^20^/cm2(K.km/s)^-1^). We find GMCs to be generally consistent within our errors between the galaxies and with Milky Way disk GMCs; the intrinsic scatter between clouds is of order a factor of two. Consistent with previous studies in the Local Group, we find a linear relationship between cloud virial mass and CO luminosity, supporting the assumption that the clouds in this GMC sample are gravitationally bound. We do not detect a significant population of GMCs with elevated velocity dispersions for their sizes, as has been detected in the Galactic center. Though the range of metallicities probed in this study is narrow, the average conversion factors of these galaxies will serve to anchor the high metallicity end of metallicity-X_CO_ trends measured using conversion factors in resolved clouds; this has been previously possible primarily with Milky Way measurements.2013ApJ...772..107Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/772/107CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/560/A24 : IRAM 30m CO-observations in W43 (Carlhoff+, 2013)J/ApJ/761/37 : CO obs. in giant molecular clouds of M33 (Miura+, 2012)J/ApJS/190/233 : Spectroscopy & abundances of SINGS galaxies (Moustakas+, 2010)J/ApJ/699/1092 : Giant molecular clouds (SRBY) (Heyer+, 2009)J/ApJ/686/948 : CO in extragalactic giant molecular clouds (Bolatto+, 2008)J/ApJS/178/56 : CO observations of LMC Giant Molecular clouds (Fukui+, 2008)J/ApJ/654/240 : Giant molecular clouds in M31 (Rosolowsky+, 2007)J/ApJ/617/240 : Oxygen abundances in the GOODS-North field (Kobulnicky+, 2004)J/ApJS/149/343 : Giant molecular clouds in M33 (Engargiola+, 2003)J/ApJS/144/47 : Outer galaxy molecular cloud catalog (Brunt+, 2003)J/PASJ/53/971 : CO catalog of LMC molecular clouds (Mizuno+, 2001)J/ApJ/428/693 : Rosette Nebula and Maddalena Cloud structures (Williams+ 1994)J/ApJS/63/821 : Inner Galaxy Molecular clouds & cloud cores (Scoville+, 1987)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/772/107https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/772/107http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/772/107https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/772/107https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/772/107http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/772/107GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/772/107/table1 (Galaxy properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/772/107/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/772/107/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/772/107/table1?GETtext/xml+votable180.050000true114.21416765.60250.005555555555555556Cone search capability for table J/ApJ/772/107/table3 (Giant molecular cloud (GMC) properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/772/107/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/772/107/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/772/107/table3?GETtext/xml+votable180.050000true308.7194460.15388890.0055555555555555566/7606 7743 10856 15592 15593 28015https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/772/107?format=asciiRadiodefaultJ/ApJ/772/107/table1Galaxy propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNGCNGC numbermeta.id;meta.mainintprimaryNcNumber of giant molecular clouds in this galaxy (table3)meta.numberintnullableRAJ2000NED Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000NED Degree of declination (J2000)pos.eq.dec;meta.mainVel[-34/408] NED optical velocitykm/sphys.veloc;pos.heliocentricintDist[3.1/7.5] Distance (1)Mpcpos.distance;pos.heliocentricfloate_DistDist uncertainty (1)Mpcstat.errorfloatMTypeMorphological typesrc.morph.typecharInc[32/60] Inclination angle (1)degsrc.orbital.inclination;pos.posAngintMet[8.9/9.2] Central metallicity 12+log(O/H) (1)phys.abund.Zfloate_MetMet uncertainty (1)stat.errorfloatf_Met[a] Flag on Met (2)meta.codecharGrad? Metallicity gradient (dex/{rho}_25_) (1)arith.grad;phys.abundfloatnullablerho25Radius of the major axis at the {mu}B=25mag/arcsec^2^ isophote (1)arcminphys.angSizefloatSimbadSimbad column added by the CDSmeta.ref.urlcharNEDSimbad column added by the CDSmeta.ref.urlcharJ/ApJ/772/107/table3Giant molecular cloud (GMC) propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNGCGalaxy NGC numbermeta.id.parentintSeq[1/87] GMC numbermeta.id;meta.mainintRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainRad[36/233] Radius (1)pcphys.size.radiusfloatsigma[2.6/21] Velocity dispersion (1)km/sphys.veloc.dispersionfloatLum[0.9/340] CO luminosityK.km.s**-1.pc**2phys.luminosity;em.radiofloatMass[2.7/761] Virial masssolMassphys.massfloatXCOConversion factor; cm^-2^/(K km/s)cm**-2.K**-1.km**-1.sarith.factorfloatArmArm class estimate (1=spiral arm; 2=interarm region)meta.codecharS/N[3.4/22] Signal-to-Noisestat.snrfloatSimbadSimbad column added by the CDSmeta.ref.urlchar