J/ApJ/831/73ivo://CDS.VizieR/J/ApJ/831/73doi:10.26093/cds/vizier.18310073CDSVutisalchavakul N.Evans II N.J.Heyer M.2018-10-08T12:07:47Z2017-02-27T12:39:57ZCDS support team

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

cds-question@unistra.frmolecular-cloudsh-ii-regionsradio-astronomyinfrared-sourcesmillimeter-astronomysubmillimeter-astronomygalaxy-planesmilky-way-galaxygalaxy-kinematicsThe relations between star formation and properties of molecular clouds (MCs) are studied based on a sample of star-forming regions in the Galactic Plane. Sources were selected by having radio recombination lines to provide identification of associated MCs and dense clumps. Radio continuum emission and mid-infrared emission were used to determine star formation rates (SFRs), while ^13^CO and submillimeter dust continuum emission were used to obtain the masses of molecular and dense gas, respectively. We test whether total molecular gas or dense gas provides the best predictor of SFR. We also test two specific theoretical models, one relying on the molecular mass divided by the free-fall time, the other using the free-fall time divided by the crossing time. Neither is supported by the data. The data are also compared to those from nearby star-forming regions and extragalactic data. The star formation "efficiency," defined as SFR divided by mass, spreads over a large range when the mass refers to molecular gas; the standard deviation of the log of the efficiency decreases by a factor of three when the mass of relatively dense molecular gas is used rather than the mass of all of the molecular gas.2016ApJ...831...73Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/831/73CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/588/A104 : Molecular clouds and star formation (Gong+, 2016)J/A+A/588/A29 : Star formation in massive clumps in Milky Way (Heyer+, 2016)J/ApJ/805/157 : BGPS. XIII. Mass functions (Ellsworth-Bowers+, 2015)J/ApJ/805/31 : IR-radio luminosities + surface densities of gal. (Liu+, 2015)J/ApJS/212/1 : The WISE catalog of Galactic HII regions (Anderson+, 2014)J/ApJ/780/173 : Masses of giant molecular clouds in MW (Battisti+, 2014)J/ApJS/209/2 : The BGPS. X. Dense molecular gas (Shirley+, 2013)J/MNRAS/431/1587 : GRS/BGPS sources in Galactic Plane (Eden+, 2013)J/ApJ/754/62 : HRDS III. HII region kinematic distances (Anderson+, 2012)J/ApJS/195/14 : The BGPS. V. (Schlingman+, 2011)J/ApJ/741/110 : The BGPS. VII. Massive star-forming regions (Dunham+, 2011)J/ApJ/723/1019 : Galactic SFR and gas surface densities (Heiderman+, 2010)J/ApJ/723/492 : Properties of GRS molecular clouds (Roman-Duval+, 2010)J/ApJS/188/123 : The Bolocam Galactic Plane Survey. II. (Rosolowsky+, 2010)J/ApJS/184/1 : Molecular clouds in the LMC by NANTEN. II. (Kawamura+, 2009)J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)J/A+A/291/943 : Protostellar cores (Ossenkopf+, 1994)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/831/73https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/831/73http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/831/73https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/831/73https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/831/73http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/831/73GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/831/73/sources (Radio recombination line sources (table 1) , star formation rates (table 2) and ^13^CO derived molecular properties (table 3))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/831/73/sources?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/831/73/sources?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/831/73/sources?GETtext/xml+votable180.050000true281.89871-1.048110.0055555555555555565/7605 6/12970 12974 12975 14353 14358 30269 30312 30313 30315 30318 30319 30330 30405 30416 30417 30601 30604 30605 30606 30618 30622 30644 30645 30688 30695 30701 30713 30717 30718 30719https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/831/73?format=asciiRadioInfraredMillimeterdefaultJ/ApJ/831/73/table4BGPS-derived dense gas propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDWISE identifier (GLLL.lll+BB.bbb) (G1)meta.id;meta.maincharMdense[128/25706]? Aggregate mass of dense gassolMassphys.massfloatnullablee_Mdense[51/10085]? Mdense 1{sigma} uncertaintysolMassstat.errorfloatnullablerdense[0.5/10]? Aggregate radius of dense gaspcphys.size.radiusfloatnullablee_rdense[0.1/2]? rdense 1{sigma} uncertaintypcstat.errorfloatnullableDGMF[0.002/0.5]? Dense gas mass fractionphys.massfloatnullablee_DGMF[0.001/0.3]? DGMF 1{sigma} uncertaintystat.errorfloatnullableJ/ApJ/831/73/sourcesRadio recombination line sources (table 1) , star formation rates (table 2) and ^13^CO derived molecular properties (table 3)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDWISE identifier (GLLL.lll+BB.bbb) (G1)meta.id;meta.maincharprimaryGDisplay the BGPS-derived dense gas properties (table 4)meta.ref.urlcharGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latVel[4/104] Radio recombination line velocitykm/sspect.dopplerVelocfloatDist[1/14] Distancekpcpos.distance;pos.heliocentricfloate_Dist[0.1/2] The 1{sigma} uncertainty in Distkpcstat.errorfloatRGal[4/8] Galactic radiuskpcpos.distance;pos.galactocentricfloatr_VelReference code for Vel (1)meta.ref;pos.frameintr_DistReference code for Dist (1)meta.ref;pos.frameintSFR-Rad[0.07/1220] Star Formation Rate from RadiosolMass/Myrphys.SFRfloate_SFR-Rad[0.01/122] The 1{sigma} error in SFR-RadsolMass/Myrstat.errorfloatSFR-MIR[0/1112] Star Formation Rate from Mid-IRsolMass/Myrphys.SFRfloate_SFR-MIR[0/112] The 1{sigma} error in SFR-MIRsolMass/Myrstat.errorfloatTypeType code (2)meta.codeintrCloud[2/34] Cloud effective radiuspcphys.size.radiusfloate_rCloud[0.01/9] The 1{sigma} error in rCloudpcstat.errorfloatdelv[0.6/4] The 1-dimensional velocity dispersionkm/spos.distance;phys.veloc.dispersionfloate_delv[0.01/2] The 1{sigma} error in delvkm/sstat.errorfloatMCloud[1/319] Cloud massksolMassphys.massfloate_MCloud[0.5/129] The 1{sigma} error in MCloudksolMassstat.errorfloatMVir[2/275] Cloud virial massksolMassphys.massfloate_MVir[0.3/96] The 1{sigma} error in MVirksolMassstat.errorfloatalpha[0.02/6] Virial parameter; MVir/MCloudphys.mass;arith.ratiofloate_alpha[0.02/3] The 1{sigma} error in alphastat.error;pos.eq.rafloatnCloud[12/8396] Cloud mean volume densitycm**-3src.densityinte_nCloud[7/5985] The 1{sigma} error in nCloudcm**-3stat.errorinttff[0.3/10] Free-fall timeMyrtime.epochfloate_tff[0.2/8] The 1{sigma} error in tffMyrstat.errorfloatRCatDisplay data from Battisti+, 2014, J/ApJ/780/173 and Ellsworth-Bowers+, 2015, J/ApJ/805/157, within 35"meta.ref.urlintnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.decnullableindexed