J/ApJ/864/120ivo://CDS.VizieR/J/ApJ/864/120doi:10.26093/cds/vizier/ba-v0-3rCDSMiura R.E.Espada D.Hirota A.Nakanishi K.Bendo G.J.Sugai H.2026-07-02T11:57:56Z2023-10-09T09:18:17ZCDS support team

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

cds-question@unistra.frgalaxiesmolecular-cloudsco-line-emissiongalaxy-kinematicsmillimeter-astronomysubmillimeter-astronomyWe present high-spatial-resolution (~0.2", or ~3pc) CO(2-1) observations of the nearest young starburst dwarf galaxy, NGC 5253, taken with the Atacama Large Millimeter/submillimeter Array. We have identified 118 molecular clouds with average values of 4.3 pc in radius and 2.2km/s in velocity dispersion, which comprise the molecular cloud complexes observed previously with ~100pc resolution. We derive for the first time in this galaxy the I(CO)-N(H_2_) conversion factor, X=4.1_-2.4_^+5.9^x10^20^cm^-2^(K.km/s)^-1^, based on the virial method. The line width and mass-to-size relations of the resolved molecular clouds present an offset on average toward higher line widths and masses with respect to quiescent regions in other nearby spiral galaxies and our Galaxy. The offset in the scaling relation reaches its maximum in regions close to the central starburst, where velocity dispersions are ~0.5dex higher and gas mass surface densities are as high as {Sigma}_H2_=10^3^M_{sun}/pc^2^. These central clouds are gravitationally bound despite the high internal pressure. A spatial comparison with star clusters found in the literature enables us to identify six clouds that are associated with young star clusters. Furthermore, the star formation efficiencies (SFEs) of some of these clouds exceed those found in star-cluster-forming clouds within our Galaxy. We conclude that once a super star cluster is formed, the parent molecular clouds are rapidly dispersed by the destructive stellar feedback, which results in such a high SFE in the central starburst of NGC 5253.2018ApJ...864..120Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/864/120CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/551/852 : FCRAO CO survey of the outer Galaxy (Heyer+, 2001)J/ApJ/603/503 : HST photometry in NGC 5253 and NGC 3077 (Harris+, 2004)J/AJ/128/2170 : H{alpha} imaging of irregular galaxies (Hunter+, 2004)J/ApJ/656/168 : Spectrophotometry in NGC 5253 (Lopez-Sanchez+, 2007)J/ApJS/178/56 : CO observations of LMC Giant Molecular clouds (Fukui+, 2008)J/ApJ/686/948 : CO in extragalactic giant molecular clouds (Bolatto+, 2008)J/ApJ/699/1092 : Giant molecular clouds (SRBY) (Heyer+, 2009)J/ApJS/184/1 : Molecular clouds in the LMC by NANTEN. II. (Kawamura+, 2009)J/AJ/140/1194 : FUV/HI relations in nearby galaxies (Bigiel+, 2010)J/ApJS/197/16 : CO observations of LMC molecular clouds (MAGMA). (Wong+, 2011)J/ApJ/761/37 : CO observations in giant molecular clouds of M33 (Miura+, 2012)J/A+A/550/A88 : Data cubes of NGC 5253 (476-682nm) (Westmoquette+, 2013)J/MNRAS/431/2917 : NGC5253 star clusters age and mass (de Grijs+, 2013)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/566/A71 : HI study of 18 nearby dwarf galaxies (Lelli+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/864/120https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/864/120http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/864/120https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/864/120https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/864/120http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/864/120GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/864/120/table3 (Properties of molecular clouds in NGC 5253)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/864/120/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/864/120/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/864/120/table3?GETtext/xml+votable180.050000true204.98213389-31.641313890.0055555555555555566/43874https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/864/120?format=asciiMillimeterRadiodefaultJ/ApJ/864/120/table3Properties of molecular clouds in NGC 5253_RARight ascension added by the CDSdegpos.eq.ra;meta.main_DEDeclination added by the CDSdegpos.eq.dec;meta.mainSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/118] Running sequence numbermeta.id;meta.mainintRAoff[-11.3/20] Intensity-weighted peak position relative to the galaxy center, {Delta}_{alpha}_ (1)arcsecpos.eq.ra;arith.diffDEoff[-10.6/12.4] Intensity-weighted peak position relative to the galaxy center, {Delta}_{delta}_ (1)arcsecpos.eq.dec;arith.diffVlsr[356/448] Local Standard of Rest velocitykm/sphys.veloc;pos.lsrintsigV[0.5/8.1] Velocity dispersion, {sigma}_V_km/sphys.veloc.dispersionfloate_sigV[0.1/5.3] sigV uncertaintykm/sstat.errorfloatmaj[1.5/17.1] Major axis of the cloud without beam deconvolution, {sigma}_maj_pcphys.sizefloatmin[1/8] Minor axis of the cloud without beam deconvolution, {sigma}_min_pcphys.sizefloatPA[-89/89] Position angle (measured counterclockwise from north to east)degpos.posAngintRad[0.9/21]? Radius (2)(3)pcphys.size.radiusfloatnullablee_Rad[0.4/10]? Rad uncertaintypcstat.errorfloatnullableSCO[0.06/9] CO(2-1) flux density, S_CO(2-1)_Jy.km/sphot.flux.density;em.mm.200-400GHzfloate_SCO[0.04/0.7] SCO uncertaintyJy.km/sstat.errorfloatMvir[0.1/107]? Virial mass (2)10000solMassphys.massfloatnullablee_Mvir[0.1/42.1]? Mvir uncertainty10000solMassstat.errorfloatnullable