J/MNRAS/452/4029ivo://CDS.VizieR/J/MNRAS/452/4029doi:10.26093/cds/vizier.74524029CDSUrquhart J.S.Figura C.C.Moore T.J.T.Csengeri T.Lumsden S.L.,Pillai T.Thompson M.A.Eden D.J.Morgan L.K.2024-08-15T20:14:34Z2017-03-14T13:32:01ZCDS support team

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

cds-question@unistra.fryoung-stellar-objectsradio-sourcesinfrared-sourcesgalaxy-classification-systemsWe present the results of ammonia observations towards 66 massive star forming regions identified by the Red Midcourse Space Experiment Source survey. We have used the Green Bank Telescope and the K-Band Focal Plane Array to map the ammonia (NH_3_) (1,1) and (2,2) inversion emission at a resolution of 30 arcsec in 8 arcmin regions towards the positions of embedded massive star formation. We have identified a total of 115 distinct clumps, approximately two-thirds of which are associated with an embedded massive young stellar object or compact HII region, while the others are classified as quiescent. There is a strong spatial correlation between the peak NH3 emission and the presence of embedded objects. We derive the spatial distribution of the kinetic gas temperatures, line widths, and NH3 column densities from these maps, and by combining these data with dust emission maps we estimate clump masses, H_2_ column densities and ammonia abundances. The clumps have typical masses of ~1000M_{sun}_ and radii ~0.5pc, line widths of ~2km/s and kinetic temperatures of ~16-20K. We find no significant difference between the sizes and masses of the star-forming and quiescent subsamples; however, the distribution maps reveal the presence of temperature and line width gradients peaking towards the centre for the star-forming clumps while the quiescent clumps show relatively uniform temperatures and line widths throughout. Virial analysis suggests that the vast majority of clumps are gravitationally bound and are likely to be in a state of global free fall in the absence of strong magnetic fields. The similarities between the properties of the two subsamples suggest that the quiescent clumps are also likely to form massive stars in the future, and therefore provide an excellent opportunity to study the initial conditions of massive pre-stellar and protostellar clumps.2015MNRAS.452.4029Uhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/452/4029CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/461/11 : Radio observations of MYSO candidates (Urquhart+, 2007)J/A+A/474/891 : 13CO observations of YSOs in South Gal. plane (Urquhart+, 2007)J/A+A/487/253 : The RMS survey: ^13^CO observations of YSOs (Urquhart+ 2008)J/A+A/501/539 : RMS survey. 6cm observations of YSOs (Urquhart+, 2009)J/ApJS/208/11 : The Red MSX Source Survey: massive protostars (Lumsden+, 2013)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/452/4029https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/452/4029http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/452/4029https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/452/4029https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/452/4029http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/452/4029GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/452/4029/table1 (Observed field parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/452/4029/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/452/4029/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/452/4029/table1?GETtext/xml+votable180.050000true272.2286667-20.09752780.005555555555555556Cone search capability for table J/MNRAS/452/4029/table2 (*The FellWalker source catalogue)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/452/4029/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/452/4029/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/452/4029/table2?GETtext/xml+votable180.050000true272.1967917-20.10002780.0055555555555555565/7278 7376 6/14352-14354 14622 14644 14689 29091-29092 29094-29095 29097 29100 29103 29463 29508-29509 29511 29522 29529 29535 30219 30241 30245 30256-30258 30268-30269 30312 30315 30318-30319 30405 30422 30616 30644 30694 30715 30719https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/452/4029?format=asciiOpticalInfraredRadiodefaultJ/MNRAS/452/4029/table1Observed field parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqField sequential numberobs.fieldintFieldField name (GLLL.lll+BB.bbb)meta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainMapMap sensitivityK.km/sinstr.sensitivityfloatNClumpNumber of clumpsmeta.numberintVLSR? LSR velocitykm/sphys.veloc;pos.lsrfloatnullableDist? Distancekpcpos.distance;pos.heliocentricfloatnullableJ/MNRAS/452/4029/table2*The FellWalker source cataloguerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqField sequential numberobs.fieldintClumpClump name (GLLL.lll+BB.bbb)meta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainmajSemi-major axisarcsecphys.angSize;srcintminSemi-minor axisarcsecphys.angSize.sminAxisintPAPosition angle measured anticlockwise from Galactic northdegpos.posAngintAspectAspect ratiosrc.morph.paramfloatthetaREffective radius of the sourcearcsecphys.angSizefloatNH3peakNH_3_ peak flux densityK.km.s**-1.beam**-1phot.flux.density;em.radiofloate_NH3peakrms uncertainty on NH3peakK.km.s**-1.beam**-1stat.errorfloatNH3intNH_3_ integrated flux densityK.km/sphot.flux.density;em.radiofloatSNRSignal-to-noise ratiostat.snrfloatSimbadSimbad column added by the CDSmeta.ref.urlcharJ/MNRAS/452/4029/table3Detected NH_3_ clump parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqField sequential numberobs.fieldintClumpClump name (GLLL.lll+BB.bbb)meta.id;meta.maincharVLSRLSR velocitykm/sphys.veloc;pos.lsrfloatDVIntrinsic FWHM line widthkm/sspect.line.widthfloate_DVrms uncertainty on DVkm/sstat.errorfloattaumainOptical depth of the transitionphys.absorption.opticalDepth;phys.atmol.transitionfloate_taumainrms uncertainty on taumainstat.errorfloatTexExcitation temperatureKphys.atmol.excitationfloate_Texrms uncertainty on TexKstat.errorfloatTrotRotation temperatureKphys.temperaturefloate_Trotrms uncertainty on TrotKstat.errorfloatTkinKinetic temperatureKphys.temperaturefloate_Tkinrms uncertainty on TkinKstat.errorfloatBffBeam filling factor (Tex/Trot)arith.factor;stat.filling;instr.beamfloatlogN(NH3)NH_3_ column density measured towards the emission peaklog(cm**-2)phys.columnDensity;stat.maxfloat<logN(NH3)>NH_3_ column density median value determined over the clumplog(cm**-2)phys.columnDensity;stat.medianfloatlog(N(NH3)/N(H2))? NH_3_ abundance measured towards the emission peakarith.zpfloatnullable<log(N(NH3)/N(H2))>? NH_3_ abundance median value determined over the clumparith.zpfloatnullableNotes[1/3]? Notes (1)meta.noteintnullableSimbadSimbad column added by the CDSmeta.ref.urlcharJ/MNRAS/452/4029/table4Matches between NH_3_ clumps and RMS sourcesRMSTypeRMS source typesrc.classcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqField sequential numberobs.fieldintClumpClump namemeta.id;meta.maincharRMSMSX Source Namemeta.idcharOffset? Angular offset between RMS and Clump positionsarcsecstat.stdev;pos.angDistancefloatnullableJ/MNRAS/452/4029/table6Derived clump parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqField sequential numberobs.fieldintClumpClump name (GLLL.lll+BB.bbb)meta.id;meta.maincharRMS?[yes/no ] RMS association ?meta.codecharDist? Distancekpcpos.distance;pos.heliocentricfloatnullableRad? Radiuskpcphys.size.radiusfloatnullablelog(PeakN(H2))? NH_2_ peak column densitylog(cm**-2)phys.columnDensity;stat.maxfloatnullablelogMclump? Clump masslog(solMass)phys.massfloatnullablelogMvir? Virial masslog(solMass)phys.massfloatnullablelogLbol? Bobometric velocity (1)log(solLum)phys.luminosityfloatnullable