J/ApJ/860/172ivo://CDS.VizieR/J/ApJ/860/172doi:10.26093/cds/vizier.18600172CDSSun J.Leroy A.K.Schruba A.Rosolowsky E.Hughes A.Kruijssen J.M.D.,Meidt S.Schinnerer E.Blanc G.A.Bigiel F.Bolatto A.D.Chevance M.,Groves B.Herrera C.N.Hygate A.P.S.Pety J.Querejeta M.Usero A.,Utomo D.2019-12-03T10:58:19Z2019-07-31T14:17:44ZCDS support team

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

cds-question@unistra.frgalaxiesinterstellar-mediumgalaxy-kinematicsmolecular-physicsco-line-emissionWe measure the velocity dispersion, {sigma}, and surface density, {Sigma}, of the molecular gas in nearby galaxies from CO spectral line cubes with spatial resolution 45-120pc, matched to the size of individual giant molecular clouds. Combining 11 galaxies from the PHANGS-ALMA survey with four targets from the literature, we characterize ~30000 independent sightlines where CO is detected at good significance. {Sigma} and {sigma} show a strong positive correlation, with the best-fit power-law slope close to the expected value for resolved, self-gravitating clouds. This indicates only a weak variation in the virial parameter {alpha}_vir_{propto}{sigma}^2^/{Sigma}, which is ~1.5-3.0 for most galaxies. We do, however, observe enormous variation in the internal turbulent pressure P_turb_{propto}{Sigma}{sigma}^2^, which spans ~5dex across our sample. We find {Sigma}, {sigma}, and P_turb_ to be systematically larger in more massive galaxies. The same quantities appear enhanced in the central kiloparsec of strongly barred galaxies relative to their disks. Based on sensitive maps of M31 and M33, the slope of the {sigma}-{Sigma} relation flattens at {Sigma}<~10M_{sun}_/pc^2^, leading to high {sigma} for a given {Sigma} and high apparent {alpha}_vir_. This echoes results found in the Milky Way and likely originates from a combination of lower beam-filling factors and a stronger influence of local environment on the dynamical state of molecular gas in the low-density regime.2018ApJ...860..172Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/860/172CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/428/693 : Rosette Nebula & Maddalena Cloud structures (Williams+ 1994)J/ApJ/551/852 : FCRAO CO survey of the outer Galaxy (Heyer+, 2001)J/ApJS/149/343 : Giant molecular clouds in M33 (Engargiola+, 2003)J/ApJ/599/1049 : Supergiant molecular complexes in Antennae (Wilson+, 2003)J/A+A/466/905 : HII regions in NGC 628 (Fathi+, 2007)J/ApJ/654/240 : Giant molecular clouds in M31 (Rosolowsky+, 2007)J/ApJ/661/830 : Giant molecular clouds of M33 (Rosolowsky+, 2007)J/ApJ/686/948 : CO in extragalactic giant molecular clouds (Bolatto+, 2008)J/AJ/136/2782 : Star formation efficiency in nearby galaxies (Leroy+, 2008)J/ApJ/699/1092 : Giant molecular clouds (SRBY) (Heyer+, 2009)J/A+A/522/A3 : M33 CO(2-1) and HI integrated intensity maps (Gratier+, 2010)J/PASP/122/1397 : Spitzer Survey of Stellar Structure in Gal. (Sheth+, 2010)J/ApJS/197/16 : CO obs. of LMC molecular clouds (MAGMA). (Wong+, 2011)J/ApJ/750/136 : Molecular clouds in the Antennae from CO(2-1) (Wei+, 2012)J/ApJ/772/107 : Giant molecular clouds in nearby gal. (Donovan Meyer+, 2013)J/ApJ/784/3 : The PAWS catalogs of GMCs and islands in M51 (Colombo+, 2014)J/A+A/580/A112 : THOR. The HI, OH, Recombination Line Survey (Bihr+, 2015)J/ApJ/803/16 : Giant MoCs in NGC4526 based on ^12^CO (Utomo+, 2015)J/ApJ/846/71 : M51 ISM structures from the CO maps of PAWS (Leroy+, 2017)J/ApJ/834/57 : MW molecular clouds from ^12^CO (Miville-Deschenes+, 2017)J/ApJ/835/278 : Molecular clouds in the dwarf galaxy NGC6822 (Schruba+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/860/172https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/860/172http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/860/172https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/860/172https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/860/172http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/860/172GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/860/172/gal (galaxies and CO detection statistics (tables 1 and 2))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/860/172/gal?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/860/172/gal?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/860/172/gal?GETtext/xml+votable180.050000true24.1740515.78346110.0055555555555555566/2155 2709 11027 18398 24912 25344 26303 27514 27728 27861 28035 28167 33920 40328 45748https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/860/172?format=asciiRadiodefaultJ/ApJ/860/172/galgalaxies and CO detection statistics (tables 1 and 2)f_fM80a: Flag on fM80 (4)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNNumber of molecular gas measurements for this galaxy (link to Table 3)meta.numberintnullableNameGalaxy namemeta.id;meta.maincharprimaryTTypeMorphological typesrc.morph.typecharDist[0.7/22] Distance from Tully+, 2009AJ....138..323TMpcpos.distance;pos.heliocentricfloatInc[6.5/77.7]? Inclinationdegsrc.orbital.inclinationfloatnullabler_Inc[a-hkrs] Reference for the inclination (1)meta.ref;pos.framecharMassStellar mass (2)1e+10solMassphys.masscharTelTelescopemeta.id;instr.telcharLineLinemeta.id;spect.linecharResResolutionarcsec/pcpos.angResolutioncharWidth[2.5/5] Channel widthkm/sspect.resolutionfloatSens[0.04/0.4] SensitivityKinstr.sensitivityfloatf_Namem="main sample" (PHANGS-ALMA targets plus M51)meta.codecharN45[408/6156]? Number of independent sightlines with confident CO detection at 45pc resolution (3)meta.numberintnullableM45[0.4/28]? Total recovered molecular gas mass at 45pc resolution1e+08solMassphys.massfloatnullablefM45[26/80]? Fraction of the recovered gas mass to the total gas mass inside the same field of view a5pc resolution%phys.mass;arith.ratiointnullableN80[308/4307]? Number of independent sightlines with confident CO detection at 80pc resolution (3)meta.numberintnullableM80[0.5/62]? Total recovered molecular gas mass at 80pc resolution1e+08solMassphys.massfloatnullablefM80[33/111]? Fraction of the recovered gas mass to the total gas mass inside the same field of view a0pc resolution%phys.mass;arith.ratiointnullableN120[183/5485] Number of independent sightlines with confident CO detection at 120pc resolution (3)meta.numberintM120[0.5/62] Total recovered molecular gas mass at 120pc resolution1e+08solMassphys.massfloatfM120[32/111] Fraction of the recovered gas mass to the total gas mass inside the same field of view a20pc resolution%phys.mass;arith.ratiointf_fM120a: Flag on fM120 (4)meta.codecharSimbadSimbad column added by the CDSmeta.ref.urlcharNEDNED column added by the CDSmeta.numbercharLEDAmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/ApJ/860/172/table3Cloud-scale molecular gas measurements for all 15 galaxiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameGalaxy namemeta.id;meta.maincharRes[45/120] Spatial resolution (1)pcpos.angResolutionintTpk[0.02/15.3] Brightness temperature at the CO line peak, see Appendix DKphys.temperaturedoubleSigma[0.7/13700] Molecular gas surface densitysolMass.pc**-2phot.flux.density.sbdoublesigV[0.6/116] Molecular gas velocity dispersionkm/sphys.veloc.dispersiondoubleaVir[0.07/92] Inferred virial parameter; see Section 5.3phys.mass;arith.ratiofloatPturb[22/3.4e+9] Inferred turbulent pressure; see Section 5.4K.cm**-3phys.pressurefloatMask1Bitmask for pixels in galaxy central region (2)meta.codecharMask2Bitmask for pixels above completeness threshold (3)meta.codechar