J/ApJ/723/1019ivo://CDS.VizieR/J/ApJ/723/1019doi:10.26093/cds/vizier.17231019CDSHeiderman A.Evans II N.J.Allen L.E.Huard T.Heyer M.2017-12-05T05:11:07Z2012-08-14T07:34:34ZCDS support team

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

cds-question@unistra.frmolecular-cloudsextinctioninterstellar-mediummilky-way-galaxyyoung-stellar-objectsWe investigate the relation between star formation rate (SFR) and gas surface densities in Galactic star-forming regions using a sample of young stellar objects (YSOs) and massive dense clumps. Our YSO sample consists of objects located in 20 large molecular clouds from the Spitzer cores to disks (c2d; Evans, 2009, Cat. J/ApJS/181/321) and Gould's Belt (GB) survey (L. Allen et al. 2010, in preparation). These data allow us to probe the regime of low-mass star formation, essentially invisible to tracers of high-mass star formation used to establish extragalactic SFR-gas relations. We estimate the gas surface density ({Sigma}_gas_) from extinction (A_V_) maps and YSO SFR surface densities ({Sigma}_SFR_) from the number of YSOs, assuming a mean mass and lifetime. We also divide the clouds into evenly spaced contour levels of A_V_, counting only Class I and Flat spectral energy distribution YSOs, which have not yet migrated from their birthplace. For a sample of massive star-forming clumps, we derive SFRs from the total infrared luminosity and use HCN gas maps to estimate gas surface densities. We find that c2d and GB clouds lie above the extragalactic SFR-gas relations (e.g., Kennicutt-Schmidt law) by factors of up to 17. We use ^12^CO and ^13^CO gas maps of the Perseus and Ophiuchus clouds from the COMPLETE survey (Ridge et al. 2006AJ....131.2921R) to estimate gas surface densities and compare to measurements from A_V_ maps.2010ApJ...723.1019Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/723/1019CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/515/A42 : Catalog of high extinction clouds (Rygl+, 2010)J/ApJ/715/310 : Early stages of star formation in IRDCs (Rathborne+, 2010)J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)J/ApJ/699/1092 : Giant molecular clouds (SRBY) (Heyer+, 2009)J/ApJS/185/198 : The Cepheus flare observed with IRAC and MIPS (Kirk+, 2009)J/ApJ/698/324 : Spitzer IRDCs (Ragan+, 2009)J/A+A/487/993 : MAMBO Mapping of c2d Clouds and Cores (Kauffmann+, 2008)J/ApJ/680/1295 : Optical spectroscopy of Cha-II PMS stars (Spezzi+, 2008)J/ApJ/680/495 : Interstellar clouds in the Gould belt (Harvey+, 2008)J/ApJ/683/822 : Star formation in Ophiuchus and Perseus II. (Jorgensen+, 2008)J/ApJS/177/551 : Spitzer c2d survey of Lupus dark clouds (Merin+, 2008)J/ApJ/663/1149 : Spitzer survey of Serpens YSO population (Harvey+, 2007)J/A+A/468/1009 : Star formation in Perseus. II. (Hatchell+, 2007)J/ApJ/551/852 : FCRAO CO survey of the outer Galaxy (Heyer+, 2001)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/723/1019https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/723/1019http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/723/1019https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/723/1019https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/723/1019http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/723/1019GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/723/1019/table1 (Measured quantities for clouds)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/723/1019/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/723/1019/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/723/1019/table1?GETtext/xml+votable180.050000true193.5-77.20.005555555555555556Cone search capability for table J/ApJ/723/1019/table3 (Properties of suspicious YSOs and MISFITS (misidentified YSOs from SED FITS) for 13 clouds)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/723/1019/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/723/1019/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/723/1019/table3?GETtext/xml+votable180.050000true64.58862538.02663330.0055555555555555566/857 858 859 860 861 862 1052 1231 1242 1263 1264 1539 1542 14029 14031 14040 14052 14053 16129 16131 16196 16197 16203 29659 29661 29663 30251 30254 30337 30340 30352 30354 30356 30358 30359 30361 30363 30366 30741 30821 36956 41099 41132 41515 42596 42597 42611 42614 42727 42736 42738 42754 42760 42785 42967 42970 42981 42982 42983 42989 43000 44374 47828https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/723/1019?format=asciiOpticaldefaultJ/ApJ/723/1019/table1Measured quantities for cloudsSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCloudCloud namemeta.id;meta.maincharprimaryn_Cloud[*] *: data from litteraturemeta.notecharNtotTotal number of YSOs above A_V_=2 (1)meta.numberintMSimbad column added by the CDSmeta.ref.urlcharNI? Number of Class I objects above A_V_=2 (1)meta.numberintnullableNF? Number of Flat SED objects >A_V_=2 (1)meta.numberintnullableDistDistance to cloudpcpos.distance;pos.heliocentricinte_Dist? Dist uncertaintypcstat.errorintnullableOmegaSolid angle (angular area {Omega}) of clouddeg**2phys.angSizefloatAreaCloud areapc**2phys.areafloate_Area? Area uncertaintypc**2stat.error;phys.areafloatnullableMassMass of cloud (gas)solMassphys.massinte_Mass? Mass uncertaintysolMassstat.error;phys.massintnullableSigmaSurface gas density {Sigma}_gas_solMass.pc**-2phot.flux.density.sbfloate_Sigma? Sigma uncertaintysolMass.pc**-2stat.errorintnullableSFRStar formation ratesolMass/Myrphys.SFRfloate_SFR? SFR uncertaintysolMass/Myrstat.error;phys.SFRfloatnullableSigSFRSFR density {Sigma}_SFR_solMass.yr**-1.kpc**-2phys.SFRfloate_SigSFR? SigSFR uncertaintysolMass.yr**-1.kpc**-2stat.errorfloatnullable_RAPositions from SIMBAD database (right ascension part)degpos.eq.ra;meta.mainnullable_DEPositions from SIMBAD database (declination part)degpos.eq.dec;meta.mainnullableJ/ApJ/723/1019/table3Properties of suspicious YSOs and MISFITS (misidentified YSOs from SED FITS) for 13 cloudsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCloudCloud namemeta.id.parentcharRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainClassSpitzer classification (see Evans et al. 2009; Cat. J/ApJS/181/321)src.classcharalphaSpectral Index, extinction corrected values for c2d clouds onlyspect.indexfloatMBdV? Integrated main beam HCO+line intensityK.km/sphot.flux.density;em.radio;meta.mainfloatnullablee_MBdV? MBdV uncertaintyK.km/sstat.errorfloatnullablel_TMBLimit flag on TMB, upper limits are computed as 2{sigma}rmsmeta.code.errorcharTMBMain beam HCO+ line temperatureKspect.line.intensity;meta.mainfloate_TMB? TMB uncertaintyKstat.errorfloatnullableSEDSED class based on Greene et al. (1994ApJ...434..614G)src.classcharl_AVLimit flag on AV (1)meta.code.errorcharAVA_V_ at source positionmagphys.absorptionintCommLine profile commentsmeta.note;spect.line.profile;spect.linecharc2dCross-match with Evans et al., 2009, Cat. J/ApJS/181/321 within 5"meta.ref.urlintnullable