J/A+A/601/A146ivo://CDS.VizieR/J/A+A/601/A146doi:10.26093/cds/vizier.36010146CDSCorbelli E.Braine J.Bandiera R.Brouillet N.Combes F.Druard C.,Gratier P.Mata J.Schuster K.Xilouris M.Palla F.2019-06-06T11:39:53Z2017-05-24T08:01:34ZCDS support team

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

cds-question@unistra.frgalaxiesmolecular-cloudsinterstellar-mediumco-line-emissionWe study the association between giant molecular clouds (GMCs) and young stellar cluster candidates (YSCCs) to shed light on the time evolution of local star formation episodes in the nearby galaxy M33. The CO (J=2-1) IRAM all-disk survey was used to identify and classify 566 GMCs with masses between 2x10^4^ and 2x10^6^M_{sun}_ across the whole star-forming disk of M33. In the same area, there are 630 YSCCs that we identified using Spitzer-24um data. Some YSCCs are embedded star-forming sites, while the majority have GALEX-UV and H{alpha} counterparts with estimated cluster masses and ages. The GMC classes correspond to different cloud evolutionary stages: inactive clouds are 32% of the total and classified clouds with embedded and exposed star formation are 16% and 52% of the total, respectively. Across the regular southern spiral arm, inactive clouds are preferentially located in the inner part of the arm, possibly suggesting a triggering of star formation as the cloud crosses the arm. The spatial correlation between YSCCs and GMCs is extremely strong, with a typical separation of 17pc. This is less than half the CO (2-1) beam size and illustrates the remarkable physical link between the two populations. GMCs and YSCCs follow the HI filaments, except in the outermost regions, where the survey finds fewer GMCs than YSCCs, which is most likely due to undetected clouds with low CO luminosity. The distribution of the non-embedded YSCC ages peaks around 5Myr, with only a few being as old as 8-10Myr. These age estimates together with the number of GMCs in the various evolutionary stages lead us to conclude that 14Myr is the typical lifetime of a GMC in M33 prior to cloud dispersal. The inactive and embedded phases are short, lasting about 4 and 2Myr, respectively. This underlines that embedded YSCCs rapidly break out from the clouds and become partially visible in H{alpha} or UV long before cloud dispersal.2017A&A...601A.146Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/601/A146CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/534/A96 : Spitzer photometry of YSC in M33 (Sharma+, 2011)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/601/A146https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/601/A146http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/601/A146https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/601/A146https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/601/A146http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/601/A146GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/601/A146/table5 (Molecular clouds in M33: properties, classes)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/601/A146/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/601/A146/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/601/A146/table5?GETtext/xml+votable180.050000true23.3617130.291410.005555555555555556Cone search capability for table J/A+A/601/A146/table6 (Young stellar cluster candidates in M33: properties and classes)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/601/A146/table6?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/601/A146/table6?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/601/A146/table6?GETtext/xml+votable180.050000true23.3749769430.309910.0055555555555555566/2154-2155 2240-22418.27688880188539e-21 8.27688880188539e-21https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/601/A146?format=asciiRadiodefaultJ/A+A/601/A146/table5Molecular clouds in M33: properties, classesNCO[1/566] Molecular cloud numbermeta.id;meta.mainintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTypeCloud type (G1)src.classcharRAJ2000Right ascension (J2000.0)degpos.eq.ra;meta.mainDEJ2000Declination (J2000.0)degpos.eq.dec;meta.mainRGalactocentric radius for cloud locationkpcpos.distance;pos.galactocentricfloatreCloud deconvolved effective radiuspcphys.size.radiusinte_reCloud radius uncertaintypcstat.errorintsigmaCCO(2-1) velocity dispersion from CROPSkm/sinstr.dispersionfloate_sigmaCCROPS velocity dispersion uncertaintykm/sstat.errorfloatsigmaG? CO(2-1) velocity dispersion from Gaussian fitkm/sinstr.dispersion;meta.modelledfloatnullableMH2Cloud luminous mass, including heliumsolMassphys.massdoublee_MH2Luminous mass uncertaintysolMassstat.errordoubleMH2vir? Cloud virial masssolMassphys.massdoublenullableNYSCC1? Identification number of associated YSCC, in table6.datmeta.id.parentintnullableNYSCC2? Identification number of associated YSCC, in table6.datmeta.id.parentintnullableNYSCC3? Identification number of associated YSCC, in table6.datmeta.id.parentintnullableNYSCC4? Identification number of associated YSCC, in table6.datmeta.id.parentintnullableSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/601/A146/table6Young stellar cluster candidates in M33: properties and classesType2Cloud type (G1)src.classcharDEJ2000Declination (J2000.0)degpos.eq.dec;meta.mainrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNYSCCYSCC identification number (1)meta.id;meta.mainintTypeYSCC type (2)src.classcharNCO1? ID number of associated molecular cloud in table5.datmeta.id.parentintnullableType1Cloud type (G1)src.classcharNCO2? ID number of associated molecular cloud in table5.datmeta.id.parentintnullableRAJ2000Right ascension (J2000.0)degpos.eq.ra;meta.mainlg(Lbol)Log10 of bolometric luminositylog(1e-07W)phys.luminosityfloatlg(LTIR)Log10 of total infrared luminositylog(1e-07W)phys.luminosity;em.IRfloatlg(LFUV)Log10 of far-UV luminositylog(1e-07W)phys.luminosity;em.UVfloatlg(LHa)Log10 of Halpha luminositylog(1e-07W)phys.luminosity;em.line.Halphafloatlg(M*)Log10 of YSCC masslog(solMass)phys.massfloatlg(Age)Log10 of YSCC agelog(yr)time.agefloatAvVisual extinctionphys.absorption;em.opt.VfloatRGalactocentric radius at YSCC locationkpcpos.distance;pos.galactocentricfloatSizeYSCC size (radius) at 24 micronarcsecphys.angSize;srcfloatF24umFlux at 24ummJyphot.flux.density;em.IR.15-30umfloatSimbadSimbad column added by the CDSmeta.ref.urlchar