J/ApJ/761/37ivo://CDS.VizieR/J/ApJ/761/37doi:10.26093/cds/vizier.17610037CDSMiura R.E.Kohno K.Tosaki T.Espada D.Hwang N.Kuno N.,Okumura S.K.Hirota A.Muraoka K.Onodera S.Minamidani T.Komugi S.,Nakanishi K.Sawada T.Kaneko H.Kawabe R.2017-06-26T11:50:26Z2014-09-05T13:32:37ZCDS support team

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

cds-question@unistra.frgalaxiesmolecular-cloudsastronomical-object-identificationstellar-associationsmillimeter-astronomysubmillimeter-astronomyWe present a giant molecular cloud (GMC) catalog of M33 (NGC598), containing 71 GMCs in total, based on wide-field and high-sensitivity CO(J=3-2) observations with a spatial resolution of 100pc using the ASTE 10m telescope. Employing archival optical data, we identify 75 young stellar groups (YSGs) from the excess of the surface stellar density, and estimate their ages by comparing with stellar evolution models. A spatial comparison among the GMCs, YSGs, and H II regions enable us to classify GMCs into four categories: Type A, showing no sign of massive star formation (SF); Type B, being associated only with H II regions; Type C, with both H II regions and <10Myr old YSGs; and Type D, with both H II regions and 10-30Myr YSGs. Out of 65 GMCs (discarding those at the edges of the observed fields), 1 (1%), 13 (20%), 29 (45%), and 22 (34%) are Types A, B, C, and D, respectively. We interpret these categories as stages in a GMC evolutionary sequence. Assuming that the timescale for each evolutionary stage is proportional to the number of GMCs, the lifetime of a GMC with a mass >10^5^M_{sun}_ is estimated to be 20-40Myr. In addition, we find that the dense gas fraction as traced by the CO(J=3-2)/CO(J=1-0) ratio is enhanced around SF regions. This confirms a scenario where dense gas is preferentially formed around previously generated stars, and will be the fuel for the next stellar generation. In this way, massive SF gradually propagates in a GMC until gas is exhausted.2012ApJ...761...37Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/761/37CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/549/A17 : IRAM spectra toward M33 GMCs (Buchbender+, 2013)J/A+A/548/A52 : Molecular cloud formation in M33 (Braine+, 2012)J/A+A/542/A108 : Giant molecular clouds in M33 (Gratier+, 2012)J/A+A/534/A96 : Spitzer photometry of YSC in M33 (Sharma+, 2011)J/MNRAS/416/2 : Photodissociation regions in M33 (Heiner+, 2011)J/A+A/522/A3 : M33 CO(2-1) and HI integrated intensity maps (Gratier+, 2010)J/ApJ/720/1674 : CFHT M33 extended sources catalog (San Roman+, 2010)J/ApJ/700/103 : Ages of star clusters in M33 (Park+, 2009)J/ApJ/699/839 : Newly identified star clusters in M33. II. (San Roman+, 2009)J/ApJ/661/830 : Giant molecular clouds of M33 (Rosolowsky+, 2007)J/A+A/476/1161 : Spitzer photometry of M33 (Verley+, 2007)J/A+A/472/785 : Radio continuum survey of M33 (Tabatabaei+, 2007)J/AJ/134/2168 : BVI photometry of M33 star clusters (Park+, 2007)J/AJ/134/447 : Catalog of star cluster candidates in M 33 (Sarajedini+, 2007)J/AJ/133/2393 : UBVRI phot. in 7 Local Group dwarfs galaxies (Massey+, 2007)J/AJ/131/2478 : M31 and M33 UBVRI photometry (Massey+, 2006)J/ApJS/149/343 : Giant molecular clouds in M33 (Engargiola+, 2003)J/PASP/111/685 : HII regions of M33. II. (Hodge+, 1999)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/761/37https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/761/37http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/761/37https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/761/37https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/761/37http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/761/37GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/761/37/table3 (M33 young stellar group catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/761/37/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/761/37/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/761/37/table3?GETtext/xml+votable180.050000true23.37583330.5291390.005555555555555556Cone search capability for table J/ApJ/761/37/gmc (Properties of the CO(J=3-2) emission components and massive star formation ; from erratum published in 2017 ApJ 834 97)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/761/37/gmc?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/761/37/gmc?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/761/37/gmc?GETtext/xml+votable180.050000true23.63833330.781250.0055555555555555566/2154 21553.322582951404819e-19 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/761/37?format=asciiRadiodefaultJ/ApJ/761/37/table3M33 young stellar group catalogSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintYSG[1/75] Young Stellar Group running sequence number in order of right ascension; <[MKT2012] YSG NN> in Simbadmeta.id;meta.mainintRAJ2000YSG central hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000YSG central degree of declination (J2000)pos.eq.dec;meta.mainl_RclLimit flag on Rclmeta.code.errorcharRcl[7.2/22.4] Size of the stellar group r_cl_ (1)arcsecphys.angSizefloatNo[9/169] Number of O stars (more massive than O9V-type stars)meta.numberintVmag[15.6/19.8] V magnitude of the brightest member in the YSG (2)magphot.mag;em.opt.VfloatE(B-V)[0.01/0.2] Applied reddening correction for each YSGmagphot.color.excessfloatn_E(B-V)[a] E(B-V) from literature (3)meta.notecharAge0[3/22] Lower estimated age of the YSGMyrtime.age;stat.minintAge1[5/50] Upper estimated age of the YSGMyrtime.age;stat.maxintXIDCross-identification(s) (4)meta.notecharMCross-match within 5" with M33 catalogs from Sarajedini et al. 2007 (J/AJ/134/447), Park et al. 2007 (J/AJ/134/2168), and San Roman et al. 2010 (J/ApJ/720/1674)meta.ref.urlintnullableJ/ApJ/761/37/gmcProperties of the CO(J=3-2) emission components and massive star formation ; from erratum published in 2017 ApJ 834 97l_R31Limit flag on R31meta.code.errorchare_R31[0.02/0.5]? R31 uncertaintystat.errorfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/71] GMC running sequence number in order of decreasing peak intensity in spectrum; <[MKT2012] NN> in Simbadmeta.id;meta.mainintf_Seq[a] a: GMC at the edge of the field of view (the provided values are lower limits)meta.codecharRAJ2000Hour of right ascension (J2000) (1)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000) (1)pos.eq.dec;meta.mainVlsr[-260/-106] Observed LSR velocity of the peak intensitykm/sphys.veloc;pos.lsrintTmb[0.1/0.9] Peak intensity in T_mb_ (main beam temperature)Kphot.fluxfloatFWHM[1/17.3] FWHM line widthkm/sspect.line.widthfloate_FWHM[0.9/15] FWHM uncertaintykm/sstat.error;phys.angSizefloatAmaj[42/189] Non-deconvolved major axispcphys.sizeintAmin[33/102] Non-deconvolved minor axispcphys.sizeintPA[5/180] Position angle (measured counterclockwise from west to north)degpos.posAngintL'CO[0.8/25.8] CO(J=3-2) luminosity (in 10^4^K.km/s.pc^2^ unit)10K.m.s**-1.kpc**2phys.luminosity;em.radiofloate_L'CO[0.4/27.5] L'CO uncertainty10K.m.s**-1.kpc**2stat.errorfloatMvir[0.2/89]? Virial mass (2)100000solMassphys.massfloatnullablee_Mvir[0.1/80]? Mvir uncertainty100000solMassstat.errorfloatnullableR31[0.1/0.9]? Averaged CO intensity ratio (J=3-2/J=1-0) over the extent of the GMCspect.line.intensity;arith.ratiofloatnullableR07? Cross-identification with R07 (3)meta.id.crossintnullablef_R07[*] Blended sources in R07 (4)meta.codecharR07a? Cross-identification with a second number of R07 (3)meta.id.crossintnullableG11Cross-identification with G11 number(s) (5)meta.id.crosscharMCross-match within 10" with GMCs in M33 from Rosolowsky et al. 2007 (J/ApJ/661/830) and Gratier et al. 2012 (J/A+A/542/A108)meta.ref.urlintnullableTypeGMC classification (6)meta.code.classcharq_Type[ab] Good (a) or bad (b) Type (7)meta.notecharYSGYoung stellar groups (YSGs) number(s) associated with the GMCsmeta.id.assoccharLHaH{alpha} luminosity in erg/s, as measured over the extent of a GMC1e-07Wphys.luminosity;em.line.HalphadoubleL24um24um luminosity in erg/s, as measured over the extent of a GMC1e-07Wphys.luminosity;em.IR.15-30umdoubleAHa[0.01/2.3] H{alpha} attenuation (8)magphys.absorptionfloatSFR[/0.05] Star formation rate (9)solMass/yrphys.SFRdoubleHIIName of the associated HII regions (10)meta.id.assoccharSimbadSimbad column added by the CDSmeta.ref.urlchar