J/ApJ/707/283ivo://CDS.VizieR/J/ApJ/707/283doi:10.26093/cds/vizier.17070283CDSJohnston K.G.Shepherd D.S.Aguirre J.E.Dunham M.K.Rosolowsky E.,Wood K.2026-05-19T14:24:40Z2012-01-26T09:37:42ZCDS support team

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

cds-question@unistra.frh-ii-regionsradio-continuum-emissiongalaxy-planesmilky-way-galaxymillimeter-astronomysubmillimeter-astronomyWe have conducted a search for ionized gas at 3.6cm, using the Very Large Array, toward 31 Galactic intermediate- and high-mass clumps detected in previous millimeter continuum observations. In the 10 observed fields, 35 HII regions are identified, of which 20 are newly discovered. Many of the HII regions are multiply peaked indicating the presence of a cluster of massive stars. We find that the ionized gas tends to be associated toward the millimeter clumps; of the 31 millimeter clumps observed, nine of these appear to be physically related to ionized gas, and a further six have ionized gas emission within 1'. For clumps with associated ionized gas, the combined mass of the ionizing massive stars is compared to the clump masses to provide an estimate of the instantaneous star formation efficiency. These values range from a few percent to 25%, and have an average of 7%+/-8%. We also find a correlation between the clump mass and the mass of the ionizing massive stars within it, which is consistent with a power law. This result is comparable to the prediction of star formation by competitive accretion that a power-law relationship exists between the mass of the most massive star in a cluster and the total mass of the remaining stars.2009ApJ...707..283Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/707/283CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/195/14 : The Bolocam Galactic Plane Survey (BGPS). V. (Schlingman+,J/ApJS/188/123 : The Bolocam Galactic Plane Survey. II. (Rosolowsky+, 2010)J/ApJS/182/131 : Molecular clouds and clumps in the GRS (Rathborne+, 2009)J/ApJ/699/1153 : Kinematic distances to GRS molecular clouds (Roman-Duval+,J/A+A/447/221 : Dust continuum emission from IRAS sources (Beltran+, 2006)J/A+A/366/481 : ATCA/VLA OH 1612 MHz survey. III. (Sevenster+, 2001)J/A+AS/115/81 : A CS(2-1) survey of UC HII regions (Bronfman+, 1996)J/ApJS/107/239 : 327MHz survey of the galactic plane (Taylor+ 1996)J/ApJS/91/347 : A 5-GHz VLA Survey of the Galactic Plane (Becker+ 1994)J/ApJS/74/181 : Small-diameter radiosources catalogue (Zoonematkermani+, 1990)J/AJ/96/1655 : Galactic plane VLA survey (Garwood+ 1988)http://www.bu.edu/galacticring/ : Galactic Ring Survey (GRS) home pagehttp://irsa.ipac.caltech.edu/data/BOLOCAM_GPS/ : BOLOCAM GPS archivehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/707/283https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/707/283http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/707/283https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/707/283https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/707/283http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/707/283GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/707/283/table1 (Observed millimeter clumps)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/707/283/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/707/283/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/707/283/table1?GETtext/xml+votable180.050000true287.85291710.4786110.005555555555555556Cone search capability for table J/ApJ/707/283/sources (Observed parameters and derived physical parameters of VLA 3.6cm sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/707/283/sources?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/707/283/sources?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/707/283/sources?GETtext/xml+votable180.050000true287.85458310.4769440.0055555555555555566/29556 30259 30317 30417 30641 30691 30694-30695 307015.517905791682326e-24 1.8058623843283312e-22https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/707/283?format=asciiRadiodefaultJ/ApJ/707/283/table1Observed millimeter clumpsSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameMillimeter clump namemeta.id;meta.maincharRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainGLONGalactic longitude of millimeter clumpdegpos.galactic.lonGLATGalactic latitude of millimeter clumpdegpos.galactic.latfloatVel? Mean velocity of associated ^13^CO Galactic Ring Survey (Jackson et al. 2006ApJS..163..145J)km/sphys.veloc;pos.lsrfloatnullablee_Vel? Vel uncertaintykm/sstat.errorfloatnullableDnearNear distance to millimeter clumpkpcpos.distance;pos.heliocentricfloatE_Dnear? Positive error on Dnearkpcstat.error;stat.maxfloatnullablee_Dnear? Negative error on Dnearkpcstat.errorfloatnullablef_Dnear[a] Flag on Dnear (1)meta.codecharDfar? Far distance to millimeter clumpkpcpos.distance;pos.heliocentricfloatnullableE_Dfar? Positive error on Dfarkpcstat.error;stat.maxfloatnullablee_Dfar? Negative error on Dfarkpcstat.errorfloatnullablef_Dfar[a] Flag on Dfar (1)meta.codecharDistAssumed distance ("Near" or "Far"), Method (2)meta.codecharLIRASLuminosity of associated IRAS sourcelog(1000solLum)phys.luminosity;em.IRcharf_LIRAS[b] Questionable IRAS association (3)meta.codecharSmmThe millimeter flux (at 1.1mm (BGPS) or 1.2mm (B06)) (4)Jyphot.flux.density;em.mm.200-400GHzfloate_Smm? Smm uncertaintyJystat.errorfloatnullableMassCalculated dust mass of the millimeter clumpsolMassphys.mass;meta.modelledintRefReference (BGPS or B06) (4)meta.ref;pos.framecharTypeSelection source type (4)meta.codecharJ/ApJ/707/283/sourcesObserved parameters and derived physical parameters of VLA 3.6cm sourcesFNumMillimeter clump sequential numbers (in table 1)obs.fieldcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFieldObserved field(s)meta.id;obs.fieldcharNameVLA source name (1)meta.id;meta.maincharFlux? Integrated flux density at 3.6cmmJyphot.flux.density;em.radio.6-12GHzdoublenullablee_Flux? Flux uncertainty (2)mJystat.error;phot.fluxfloatnullablef_Flux[b] multiply peaked source (2)meta.codecharRAJ2000? Peak hour of right ascension (J2000) (3)pos.eq.ra;meta.mainnullableDEJ2000? Peak degree of declination (J2000)pos.eq.dec;meta.mainnullablePk? Peak flux density in mJy/beammJyphot.flux.density;em.radio.6-12GHzfloatnullablee_Pk? Pk uncertaintymJystat.errorfloatnullablel_amajLimit flag on amajmeta.code.errorcharamaj? Angular size for the major axisarcsecphys.angSizefloatnullablel_bminLimit flag on bminmeta.code.errorcharbmin? Angular size for the minor axisarcsecphys.angSize;srcfloatnullablePA[-80,178]? Position angledegpos.posAngintnullableSA? Solid angle in units of steradiansx10^-8^ unit (4)1e-08srphys.angSizefloatnullableONameAlernative identifier(s) for VLA source or "New"meta.idcharP[I/U] I: Irregular or U: Unresolved (5)meta.codecharDist? Assumed distance (6)kpcpos.distance;pos.galactocentricfloatnullablel_theta[<] Limit flag on thetameta.code.error;pos.posAngchartheta? Effective angular diameter of the source (7)arcsecphys.angSizefloatnullablel_s[<] Limit flag on smeta.code.errorchars? Physical size ({Delta}s) (8)pcphys.angSizefloatnullablel_Tb[>] Limit flag on Tbmeta.code.errorcharTb? Brightness temperature (7)Kphys.temperaturefloatnullablel_tau[>] Limit flag on taumeta.code.errorchartau? Optical depth (7)phys.absorption.opticalDepthfloatnullablel_EM[>] Limit flag on EMmeta.code.errorcharEM? Emission measure (5)(9)1e+06pc.cm**-6phys.emissMeasurefloatnullablene? Number density of electrons (n_e_) (in 10^3^/cm^3^) (7)mm**-3meta.number;phys.densityfloatnullableU? Excitation parameter U (rn_e_^2/3^) (7)pc.cm**-2phys.excitParamfloatnullablelogNLy? Ionization rate (7)log(s**-1)phys.luminosityfloatnullableSpTMK Spectral type (5)(10)src.spTypecharLcm? Luminosity (5)(10)1000solLumphys.luminosity;em.radiofloatnullableSimbadSimbad column added by the CDSmeta.refchar