J/ApJ/803/16ivo://CDS.VizieR/J/ApJ/803/16doi:10.26093/cds/vizier.18030016CDSUtomo D.Blitz L.Davis T.Rosolowsky E.Bureau M.Cappellari M.,Sarzi M.2017-09-12T11:43:45Z2015-09-02T12:50:18ZCDS support team

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

cds-question@unistra.frgalaxiesmolecular-cloudsgalaxy-kinematicsradio-astronomyWe present a high spatial resolution (~20pc) of ^12^CO(2-1) observations of the lenticular galaxy NGC 4526. We identify 103 resolved giant molecular clouds (GMCs) and measure their properties: size R, velocity dispersion {sigma}_v_, and luminosity L. This is the first GMC catalog of an early-type galaxy. We find that the GMC population in NGC 4526 is gravitationally bound, with a virial parameter {alpha}~1. The mass distribution, dN/dM{propto}M^-2.39+/-0.03^, is steeper than that for GMCs in the inner Milky Way, but comparable to that found in some late-type galaxies. We find no size-line width correlation for the NGC 4526 clouds, in contradiction to the expectation from Larson's relation. In general, the GMCs in NGC 4526 are more luminous, denser, and have a higher velocity dispersion than equal-size GMCs in the Milky Way and other galaxies in the Local Group. These may be due to higher interstellar radiation field than in the Milky Way disk and weaker external pressure than in the Galactic center. In addition, a kinematic measurement of cloud rotation shows that the rotation is driven by the galactic shear. For the vast majority of the clouds, the rotational energy is less than the turbulent and gravitational energy, while the four innermost clouds are unbound and will likely be torn apart by the strong shear at the galactic center. We combine our data with the archival data of other galaxies to show that the surface density {Sigma} of GMCs is not approximately constant, as previously believed, but varies by ~3 orders of magnitude. We also show that the size and velocity dispersion of the GMC population across galaxies are related to the surface density, as expected from the gravitational and pressure equilibrium, i.e., {sigma}_v_R^-1/2^{propto}{Sigma}^1/2^.2015ApJ...803...16Uhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/803/16CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/565/A128 : Dust SED in HRS nearby galaxies (Ciesla+, 2014)J/A+A/542/A108 : Giant molecular clouds in M33 (Gratier+, 2012)J/ApJS/197/16 : CO obs. of LMC molecular clouds (MAGMA). (Wong+, 2011)J/MNRAS/413/813 : ATLAS3D project. I. (Cappellari+, 2011)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/661/830 : Giant molecular clouds of M33 (Rosolowsky+, 2007)J/ApJ/654/240 : Giant molecular clouds in M31 (Rosolowsky+, 2007)J/ApJS/149/343 : Giant molecular clouds in M33 (Engargiola+, 2003)J/ApJ/551/852 : FCRAO CO survey of the outer Galaxy (Heyer+, 2001)J/A+AS/134/241 : Rotation in molecular clouds (Phillips 1999)J/ApJ/428/693 : Rosette Nebula & Maddalena Cloud structures (Williams+ 1994)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/803/16https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/803/16http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/803/16https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/803/16https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/803/16http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/803/16GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/803/16/table1 (NGC4526 cloud properties from ^12^CO(2-1) line)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/803/16/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/803/16/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/803/16/table1?GETtext/xml+votable180.050000true188.5145837.6985280.0055555555555555566/27728https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/803/16?format=asciiRadiodefaultJ/ApJ/803/16/table1NGC4526 cloud properties from ^12^CO(2-1) linerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/241] Running sequence numbermeta.id;meta.mainintRAJ2000[12] Hour of the Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[7] Degree of Declination (J2000)pos.eq.dec;meta.mainVLSR[276/959] Local Standard of Rest velocitykm/sphys.veloc;pos.lsrfloatR[3/41]? Cloud size (1)pcphys.size.radiusfloatnullablee_R[2/15]? Uncertainty in R (1)pcstat.errorfloatnullablesigv[3.7/27.5] Velocity dispersion {sigma}km/sphys.veloc.dispersionfloate_sigvi[0.3/158] Uncertainty in sigvkm/sstat.errorfloatLum[0.1/12] Luminosity in ^12^CO(2-1) (1.3mm)100000K.km.s**-1.pc**2phys.luminosity;em.radiofloate_Lum[0.09/2.14] Uncertainty in Lum100000K.km.s**-1.pc**2stat.errorfloatMass[0.09/6] Cloud mass1e+06solMassphys.massfloate_Mass[0.05/1.1] Uncertainty in Mass1e+06solMassstat.error;phys.massfloatS/N[3/7.5] Signal-to-noise ratiostat.snrfloatTbmax[3.7/10.4] Maximum brightness temperatureKphys.temperature;stat.maxfloatOmega[0.4/66.1]? Angular velocity {Omega}_shear_ due to the galactic shearkm.s**-1.pc**-1arith.grad;phys.velocfloatnullableDist[10/874]? Distance from NGC4526 center (2)pcpos.distance;pos.galactocentricintnullableSimbadSimbad column added by the CDSmeta.ref.urlchar