J/ApJ/964/12ivo://CDS.VizieR/J/ApJ/964/12CDSFinn M.K.Johnson K.E.Indebetouw R.Costa A.H.Adamo A.Aloisi A.,Bittle L.Calzetti D.Dale D.A.Dobbs C.L.Donovan Meyer J.,Elmegreen B.G.Elmegreen D.M.Fumagalli M.Gallagher J.S.Grasha K.,Grebel E.K.Kennicutt R.C.Krumholz M.R.Lee J.C.Messa M.Nair P.,Sabbi E.Smith L.J.Thilker D.A.Whitmore B.C.Wofford A.2026-07-28T08:09:39Z2026-07-28T09:06:02ZCDS support team

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

cds-question@unistra.frgalaxiesmolecular-cloudsinterstellar-mediummillimeter-astronomysubmillimeter-astronomyco-line-emissionvisible-astronomygalaxy-kinematicsWe present a comparative study of the molecular gas in two galaxies from the Legacy ExtraGalactic UV Survey (LEGUS) sample: barred spiral NGC 1313 and flocculent spiral NGC 7793. These two galaxies have similar masses, metallicities, and star formation rates, but NGC 1313 is forming significantly more massive star clusters than NGC 7793, especially young massive clusters (<10Myr, >10^4^M_{sun}_). Using Atacama Large Millimeter/submillimeter Array (ALMA) CO(2-1) observations of the two galaxies with the same sensitivity and resolution (13pc), we directly compare the molecular gas in these two similar galaxies to determine the physical conditions responsible for their large disparity in cluster formation. By fitting size-line width relations for the clouds in each galaxy, we find that NGC 1313 has a higher intercept than NGC 7793, implying that its clouds have higher kinetic energies at a given size scale. NGC 1313 also has more clouds near virial equilibrium than NGC 7793, which may be connected to its higher rate of massive cluster formation. However, these virially bound clouds do not show a stronger correlation with young clusters than with the general cloud population. We find surprisingly small differences between the distributions of molecular cloud populations in the two galaxies, though the largest of those differences is that NGC 1313 has higher surface densities and lower freefall times.2024ApJ...964...12Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/964/12CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/128/16 : HIPASS Bright Galaxy Catalog (Koribalski+, 2004)J/ApJ/686/948 : CO in extragalactic giant molecular clouds (Bolatto+, 2008)J/ApJ/706/599 : H{alpha} and UV SFR in the local volume (Lee+, 2009)J/ApJS/197/16 : CO observations of LMC molecular clouds (MAGMA). (Wong+, 2011)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/ApJ/812/39 : Fluxes of NGG7793 & NGC4945 with GMOS-S (Stanghellini+, 2015)J/ApJ/821/125 : SMA obs. of giant molecular clouds in NGC 300 (Faesi+, 2016)J/ApJ/834/57 : MW molecular clouds from ^12^CO (Miville-Deschenes+, 2017)J/ApJ/841/92 : Young massive star clusters in 2 LEGUS galaxies (Ryon+, 2017)J/MNRAS/478/1611 : Local Volume H I Survey (LVHIS) (Koribalski+, 2018)J/ApJS/235/23 : LEGUS galaxies1 observations (Sabbi+, 2018)J/ApJ/860/172 : Cloud-scale molecular gas properties in 15 gal. (Sun+, 2018)J/ApJS/245/14 : 8um cores in the spiral arms of nearby gal. (Elmegreen+, 2019)J/ApJ/901/L8 : Molecular gas properties of 70 PHANGS-ALMA gal. (Sun+, 2020)J/ApJS/257/43 : PHANGS-ALMA: arcsecond CO(2-1) imaging of gal. (Leroy+, 2021)J/ApJ/909/121 : Young star clusters in NGC1313 with HST obs. (Messa+, 2021)J/ApJ/927/149 : Low-J CO line ratios for 152 CO map pairs (Leroy+, 2022)J/ApJ/932/47 : ALMA CO obs. of the 30 Dor MoC complex (Wong+, 2022)J/MNRAS/520/63 : Cl* ages, masses & extinctions of 4 galaxies (Whitmore+, 2023)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/964/12https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/964/12http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/964/12https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/964/12https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/964/12http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/964/12GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/964/12/table5 (Catalog of NGC 1313 dendrogram properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/964/12/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/964/12/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/964/12/table5?GETtext/xml+votable180.050000true49.5522-66.51070.005555555555555556Cone search capability for table J/ApJ/964/12/table6 (Catalog of NGC 1313 clump properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/964/12/table6?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/964/12/table6?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/964/12/table6?GETtext/xml+votable180.050000true49.6572-66.49270.005555555555555556Cone search capability for table J/ApJ/964/12/table7 (Catalog of NGC 7793 dendrogram properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/964/12/table7?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/964/12/table7?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/964/12/table7?GETtext/xml+votable180.050000true359.4799-32.58920.005555555555555556Cone search capability for table J/ApJ/964/12/table8 (Catalog of NGC 7793 clump properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/964/12/table8?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/964/12/table8?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/964/12/table8?GETtext/xml+votable180.050000true359.4553-32.58080.0055555555555555566/16441 33193https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/964/12?format=asciiOpticalMillimeterRadiodefaultJ/ApJ/964/12/table5Catalog of NGC 1313 dendrogram propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/676] Identification numbermeta.id;meta.mainintRAJ2000[49.49/49.7] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-66.52/-66.46] Declination (J2000)degpos.eq.dec;meta.mainWCO[55/31470] Observed brightness of CO(2-1)K.km/sphot.flux.density;em.line.COinte_WCO[2/31] Uncertainty in WCOK.km/sstat.error;phot.flux.density;em.line.COintCOmax[1.1/8] Maximum CO(2-1) temperatureKstat.max;phys.temperature;em.line.COfloatMass[1.6/260] Mass1000solMassphys.massfloate_Mass[0.16/26] Uncertainty in Mass1000solMassstat.error;phys.massfloatRadius[0.14/10] Radiuspcphys.size.radiusfloate_Radius[8e-05/0.7] Uncertainty in Radiuspcstat.error;phys.size.radiusdoublesigmav[3.6/85] Dispersion velocitykm/sphys.veloc.dispersionfloate_sigmav[0.98/79] Uncertainty in sigmavkm/sstat.max;phys.veloc.dispersionfloataVir[0.04/79] The virial parameterphys.mass;arith.ratiofloate_aVir[0.03/41] Uncertainty in aVirstat.error;phys.mass;arith.ratiofloatSigma[1/92] Surface densitysolMass.pc**-2phot.flux.density.sbfloate_Sigma[0.12/540] Uncertainty in SigmasolMass.pc**-2stat.error;phot.flux.density.sbfloatlogPe/kB[0.47/5.5] Log external pressure divided by k_B_log(K.cm**-3)phys.pressure;arith.ratiofloate_logPe/kB[0.04/1.5] Uncertainty in logPe/kBlog(K.cm**-3)stat.error;phys.pressure;arith.ratiofloattff[1.9/53] Free-fall timeMyrtimefloate_tff[0.66/46] Uncertainty in tffMyrstat.error;timefloatJ/ApJ/964/12/table6Catalog of NGC 1313 clump propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/644] Identification numbermeta.id;meta.mainintRAJ2000[49.49/49.7] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-66.52/-66.46] Declination (J2000)degpos.eq.dec;meta.mainWCO[47/7222] Observed brightness of CO(2-1)K.km/sphot.flux.density;em.line.COinte_WCO[2/12] Uncertainty in WCOK.km/sstat.error;phot.flux.density;em.line.COintCOmax[0.9/8] Maximum CO(2-1) temperatureKstat.max;phys.temperature;em.line.COfloatMass[1.3/61] Mass1000solMassphys.massfloate_Mass[0.14/6.1] Uncertainty in Mass1000solMassstat.error;phys.massfloatRadius[0.14/5.5] Radiuspcphys.size.radiusfloate_Radius[6e-05/0.4] Uncertainty in Radiuspcstat.error;phys.size.radiusdoublesigmav[2.9/48] Dispersion velocitykm/sphys.veloc.dispersionfloate_sigmav[0.98/21] Uncertainty in sigmavkm/sstat.max;phys.veloc.dispersionfloataVir[0.043/48] The virial parameterphys.mass;arith.ratiofloate_aVir[0.026/23] Uncertainty in aVirstat.error;phys.mass;arith.ratiofloatSigma[1/67] Surface densitysolMass.pc**-2phot.flux.density.sbfloate_Sigma[0.1/250] Uncertainty in SigmasolMass.pc**-2stat.error;phot.flux.density.sbfloatlogPe/kB[0.7/5.2] Log external pressure divided by k_B_log(K.cm**-3)phys.pressure;arith.ratiofloate_logPe/kB[0.04/1.4] Uncertainty in logPe/kBlog(K.cm**-3)stat.error;phys.pressure;arith.ratiofloattff[2.1/54] Free-fall timeMyrtimefloate_tff[0.6/25] Uncertainty in tffMyrstat.error;timefloatJ/ApJ/964/12/table7Catalog of NGC 7793 dendrogram propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/1193] Identification numbermeta.id;meta.mainintRAJ2000[359.4/359.5] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-32.61/-32.56] Declination (J2000)degpos.eq.dec;meta.mainWCO[52/54350] Observed brightness of CO(2-1)K.km/sphot.flux.density;em.line.COinte_WCO[1/31] Uncertainty in WCOK.km/sstat.error;phot.flux.density;em.line.COintCOmax[0.88/7] Maximum CO(2-1) temperatureKstat.max;phys.temperature;em.line.COfloatMass[1.3/390] Mass1000solMassphys.massfloate_Mass[0.13/39] Uncertainty in Mass1000solMassstat.error;phys.massfloatRadius[0.18/11] Radiuspcphys.size.radiusfloate_Radius[3e-05/0.7] Uncertainty in Radiuspcstat.error;phys.size.radiusdoublesigmav[3.8/220] Dispersion velocitykm/sphys.veloc.dispersionfloate_sigmav[0.9/98] Uncertainty in sigmavkm/sstat.max;phys.veloc.dispersionfloataVir[0.12/120] The virial parameterphys.mass;arith.ratiofloate_aVir[0.04/75] Uncertainty in aVirstat.error;phys.mass;arith.ratiofloatSigma[0.59/88] Surface densitysolMass.pc**-2phot.flux.density.sbfloate_Sigma[0.07/690] Uncertainty in SigmasolMass.pc**-2stat.error;phot.flux.density.sbfloatlogPe/kB[0.58/5.3] Log external pressure divided by k_B_log(K.cm**-3)phys.pressure;arith.ratiofloate_logPe/kB[0.2/7.6] Uncertainty in logPe/kBlog(K.cm**-3)stat.error;phys.pressure;arith.ratiofloattff[2.2/120] Free-fall timeMyrtimefloate_tff[0.49/68] Uncertainty in tffMyrstat.error;timefloatJ/ApJ/964/12/table8Catalog of NGC 7793 clump propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/1131] Identification numbermeta.id;meta.mainintRAJ2000[359.4/359.5] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-32.61/-32.56] Declination (J2000)degpos.eq.dec;meta.mainWCO[38/15170] Observed brightness of CO(2-1)K.km/sphot.flux.density;em.line.COinte_WCO[1/14] Uncertainty in WCOK.km/sstat.error;phot.flux.density;em.line.COintCOmax[0.6/7] Maximum CO(2-1) temperatureKstat.max;phys.temperature;em.line.COfloatMass[1.1/110] Mass1000solMassphys.massfloate_Mass[0.1/11] Uncertainty in Mass1000solMassstat.error;phys.massfloatRadius[0.14/4.4] Radiuspcphys.size.radiusfloate_Radius[3e-05/0.3] Uncertainty in Radiuspcstat.error;phys.size.radiusdoublesigmav[3.4/55] Dispersion velocitykm/sphys.veloc.dispersionfloate_sigmav[0.9/30] Uncertainty in sigmavkm/sstat.max;phys.veloc.dispersionfloataVir[0.1/59] The virial parameterphys.mass;arith.ratiofloate_aVir[0.015/25] Uncertainty in aVirstat.error;phys.mass;arith.ratiofloatSigma[0.59/58] Surface densitysolMass.pc**-2phot.flux.density.sbfloate_Sigma[0.07/200] Uncertainty in SigmasolMass.pc**-2stat.error;phot.flux.density.sbfloatlogPe/kB[0.58/5.1] Log external pressure divided by k_B_log(K.cm**-3)phys.pressure;arith.ratiofloate_logPe/kB[0.043/1.4] Uncertainty in logPe/kBlog(K.cm**-3)stat.error;phys.pressure;arith.ratiofloattff[2.6/68] Free-fall timeMyrtimefloate_tff[0.7/32] Uncertainty in tffMyrstat.error;timefloat