J/ApJ/852/2ivo://CDS.VizieR/J/ApJ/852/2doi:10.26093/cds/vizier.18520002CDSWenger T.V.Khan A.A.Ferraro N.G.Balser D.S.Armentrout W.P.,Anderson L.D.Bania T.M.2025-05-22T20:11:21Z2023-09-25T15:15:47ZCDS support team

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

cds-question@unistra.frmilky-way-galaxyco-line-emissionmolecular-physicsinterstellar-mediumh-ii-regionsradio-astronomyinfrared-sourcesThe Outer Scutum-Centaurus arm (OSC) is the most distant molecular spiral arm known in the Milky Way. The OSC may be the very distant end of the well-known Scutum-Centaurus arm, which stretches from the end of the Galactic bar to the outer Galaxy. At this distance the OSC is seen in the first Galactic quadrant. The population of star formation tracers in the OSC remains largely uncharacterized. Extragalactic studies show a strong correlation between molecular gas and star formation, and carbon monoxide (CO) emission was recently discovered in the OSC. Here we use the Arizona Radio Observatory (ARO) 12m telescope to observe the ^12^CO J=1-0 and ^13^CO J=1-0 transitions toward 78 HII region candidates chosen from the WISE Catalog of Galactic HII Regions. These targets are spatially coincident with the Galactic longitude-latitude (l,b) OSC locus as defined by HI emission. We detect CO emission in ~80% of our targets. In total, we detect 117 ^12^CO and 40 ^13^CO emission lines. About two-thirds of our targets have at least one emission line originating beyond the solar orbit. Most of the detections beyond the solar orbit are associated with the outer arm, but there are 17 ^12^CO emission lines and 8 ^13^CO emission lines with LSR velocities that are consistent with the velocities of the OSC. There is no apparent difference between the physical properties (e.g., molecular column density) of these OSC molecular clouds and non-OSC molecular clouds within our sample.2018ApJ...852....2Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/852/2CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/54 : Atlas of Galactic Neutral Hydrogen (Hartmann+, 1997)VIII/75 : HI survey of the sky DE<+25{deg} (Bajaja+, 2005)VIII/76 : Leiden/Argentine/Bonn (LAB) Survey of Galactic HI (Kalberla+ 2005)J/A+A/275/67 : Velocity Field of the outer Galaxy (Brand+ 1993)J/A+A/417/107 : CO velocities in southern HII regions (Russeil+, 2004)J/ApJS/181/255 : CO in Galactic HII regions (Anderson+, 2009)J/ApJ/754/62 : HRDS III. HII region kinematic distances (Anderson+, 2012)J/ApJ/783/130 : Parallaxes of high mass star forming regions (Reid+, 2014)J/ApJ/798/L27 : CO obs. of molecular clouds in the 2nd quadrant (Sun+, 2015)J/ApJS/221/26 : Radio obs. of Galactic WISE HII regions (Anderson+, 2015)J/ApJS/230/17 : CO obs. of MCs in the Extreme Outer Galaxy region (Sun+, 2017)J/ApJ/841/121 : HII region cand. in the OSC spiral arm (Armentrout+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/852/2https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/852/2http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/852/2https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/852/2https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/852/2http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/852/2GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/852/2/emlines (12CO (Table 1) and 13CO (Table2) emission line parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/852/2/emlines?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/852/2/emlines?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/852/2/emlines?GETtext/xml+votable180.050000true276.10531-9.344070.005555555555555556Cone search capability for table J/ApJ/852/2/table3 (Molecular cloud properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/852/2/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/852/2/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/852/2/table3?GETtext/xml+votable180.050000true281.869760.592510.0055555555555555566/14336 14342 14344 14360 14363-14364 14366-14367 14389 14391 14411 14435 14448 29530 29533 30243 30252-30253 30266 30271 30314 30400 30404 30421 30425 30429 30506 30592 30602-30603 30606 30625-30626 30628 30643 30646-30649 30696-30697 30703 30712 30714 30718 32069 32081-32082 32084-32085 32092https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/852/2?format=asciiInfraredRadiodefaultJ/ApJ/852/2/emlines12CO (Table 1) and 13CO (Table2) emission line parameterse_Vlsr[0/1.2]? Vlsr 1{sigma} uncertaintykm/sstat.error;phys.veloc;pos.lsrfloatnullableDelV[0.66/6.6]? FWHM line width, {Delta}Vkm/sspect.line.widthfloatnullablee_DelV[0.01/2.81]? DelV 1{sigma} uncertaintykm/sstat.errorfloatnullablerms[0.009/0.06] The root-mean-square noise in the line-free baselineKstat.snrfloatExp[9.7/78] The total integration time, t_intg_mintime.epochfloatQF[A-D] Quality factor (A=best) (3)meta.code.qualcharA14Display data from Anderson+ 2014, J/ApJS/212/1 within 15"meta.ref.urlintnullableA17Display data from Armentrout+ 2017, J/ApJ/841/121 within 10"meta.ref.urlintnullableMoCDisplay the molecular cloud properties (link to Table 3)meta.ref.urlintnullable_GlonPositions from names (longitude part)degpos.galactic.lon_GlatPositions from names (latitude part)degpos.galactic.lat_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.raindexed_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.decindexedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMol12CO or 13CO emission line parametersmeta.codecharNameTarget name (GLLL.lll+B.bbb)meta.id;meta.maincharprimarym_NameComponent on Name (1)meta.code.multipcharf_Name[V] Flag on Name (2)meta.codecharTL[0.1/22.3]? The peak line intensity, T_L_Kspect.line.intensity;stat.maxfloatnullablee_TL[0/0.8]? TL 1{sigma} uncertaintyKstat.errorfloatnullableVlsr[-89.1/72.5]? LSR velocitykm/sphys.veloc;pos.lsrfloatnullableJ/ApJ/852/2/table3Molecular cloud properties_GlatPositions from names (latitude part)degpos.galactic.latrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintName^12^CO component name (GLLL.lll+B.bbb)meta.id;meta.maincharm_NameComponent on Namemeta.code.multipcharVlsr[-84.81/6.87] LSR velocitykm/sphys.veloc;pos.lsrfloatRgal[8.22/15.77] Galactocentric radiuskpcphys.size.radius;pos.galactocentricfloatDist[0.38/20.81] Distance from the Sunkpcpos.distance;pos.heliocentricfloatDist2[12.39]? Second value of distance (1)kpcpos.distance;pos.heliocentricfloatnullableT12CO[0.99/9.6] ^12^CO line intensityKspect.line.intensityfloatT13CO[0.1/1.9] ^13^CO line intensityKspect.line.intensityfloat_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.raindexed_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.decindexedNH2[0.79/28.12] NH2 column density1e+20cm**-2phys.columnDensityfloat_GlonPositions from names (longitude part)degpos.galactic.lon