J/ApJS/230/17ivo://CDS.VizieR/J/ApJS/230/17doi:10.26093/cds/vizier.22300017CDSSun Y.Su Y.Zhang S.-B.Xu Y.Chen X.-P.Yang J.Jiang Z.-B.,Fang M.2020-06-15T07:01:15Z2017-08-17T14:21:11ZCDS support team

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

cds-question@unistra.frco-line-emissionsurveysmolecular-cloudsmilky-way-galaxyWe present the results of an unbiased CO survey in the Galactic range of 34.75{deg}<=l<=45.25{deg} and -5.25{deg}<=b<=5.25{deg}, and the velocity range beyond the Outer arm. A total of 168 molecular clouds (MCs) are identified within the Extreme Outer Galaxy (EOG) region, and 31 of these MCs are associated with ^13^CO emission. However, none of them show significant C^18^O emission under the current detection limit. The typical size and mass of these MCs are 5pc and 3x10^3^M_{sun}_, implying a lack of large and massive MCs in the EOG region. Similar to MCs in the outer Galaxy, the velocity dispersions of EOG clouds are also correlated with their sizes; however, they are well displaced below the scaling relationship defined by the inner Galaxy MCs. These MCs with a median Galactocentric radius of 12.6kpc show very different distributions from those of the MCs in the Outer arm published in our previous paper, while roughly following the Outer Scutum-Centaurus arm defined by Dame & Thaddeus (2011ApJ...734L..24D). This result may provide robust evidence for the existence of the Outer Scutum-Centaurus arm. The lower limit of the total mass of this segment is about 2.7x10^5^M_{sun}_, which is about one magnitude lower than that of the Outer arm. The mean thickness of the gaseous disk is about 1.45{deg} or 450pc, and the scale height is about 1.27{deg}, or 400pc above the b=0{deg} plane. The warp traced by CO emission is very obvious in the EOG region and its amplitude is consistent with the predictions by other warp models using different tracers, such as dust, HI, and stellar components of our Galaxy.2017ApJS..230...17Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/230/17CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/114 : Massachusetts-Stony Brook Galactic Plane CO Survey (Clemens+ 1986)VIII/76 : Leiden/Argentine/Bonn (LAB) Survey of Galactic HI (Kalberla+ 2005)J/ApJS/63/821 : Inner Galaxy MCs and cloud cores (Scoville+, 1987)J/A+A/275/67 : Velocity Field of the outer Galaxy (Brand+ 1993)J/ApJ/551/852 : FCRAO CO survey of the outer Galaxy (Heyer+, 2001)J/A+A/382/513 : Galaxy warps in the HDF North and South (Reshetnikov+, 2002)J/ApJS/144/47 : Outer galaxy molecular cloud catalog (Brunt+, 2003)J/A+A/397/133 : Star-forming complexes in the Galaxy (Russeil+, 2003)J/PASJ/57/917 : CO MCs in southern Galactic Warp (Nakagawa+, 2005)J/A+A/453/635 : Modelling Galactic Interstellar Extinction (Marshall+, 2006)J/ApJ/686/948 : CO in extragalactic giant molecular clouds (Bolatto+, 2008)J/ApJ/699/1092 : Giant molecular clouds (SRBY) (Heyer+, 2009)J/ApJ/723/492 : Properties of GRS molecular clouds (Roman-Duval+, 2010)J/A+A/569/A125 : Spiral structure of the Milky Way (Hou+, 2014)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/224/7 : CO obs. of the outer arm in the 2nd quadrant (Du+, 2016)J/ApJ/828/59 : Molecular clouds in the Milky Way with CO obs. (Su+, 2016)J/ApJ/834/57 : MW molecular clouds from ^12^CO (Miville-Deschenes+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/230/17https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/230/17http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/230/17https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/230/17https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/230/17http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/230/17GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/230/17/table1 (Parameters of molecular clouds (MCs) derived by ^12^CO(1-0))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/230/17/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/230/17/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/230/17/table1?GETtext/xml+votable180.050000true285.016340.956270.005555555555555556Cone search capability for table J/ApJS/230/17/table2 (Molecular clouds marginally detected by this study)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/230/17/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/230/17/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/230/17/table2?GETtext/xml+votable180.050000true283.785072.299080.005555555555555556Cone search capability for table J/ApJS/230/17/table3 (Parameters of molecular clouds derived by ^13^CO(1-0))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/230/17/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/230/17/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/230/17/table3?GETtext/xml+votable180.050000true284.576291.266340.0055555555555555565/7606 7607 7650 7656 7657 7660 6/30317 30405 30406 30416 30417 30419 30420 30422 30452 30453 30461 30506 30592 30606 30617 30619 30644 30648 30649https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/230/17?format=asciiRadiodefaultJ/ApJS/230/17/table1Parameters of molecular clouds (MCs) derived by ^12^CO(1-0)f_MWISPFlag on MWISP (2)meta.codecharDist[16.6/20] Heliocentric distance (4)kpcpos.distancefloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMWISPCloud identifier (GLL.lll+B.bbb) (1)meta.id;meta.maincharprimaryVLSR[-74/-45] Local Standard of Rest velocity (3)km/sphys.veloc;pos.lsrfloatDelV[0.5/5.3] Line width Full-Width at Half-Maximum (3)km/sspect.line.widthfloatInt[1/21] Integrated ^12^CO intensity (3)K.km/sphot.flux.density;em.line.COfloatTpk[1/7] Peak intensity (3)Kphot.antennaTempfloatArea[0.9/27] Angular area defined by 3{sigma} limitsarcmin**2phys.angAreafloatR[11.6/14.1] Galactocentric distance (4)kpcpos.distance;pos.galactocentricfloatZ[-0.5/1.5] Vertical scale height (5)kpcpos.cartesian.z;pos.galacticfloatRad[1/15] Cloud radius after beam deconvolutionpcphys.size.radius;instr.beamfloatMass[1/139] Cloud mass (6)100solMassphys.massfloatMvir[1/691] Virial mass100solMassphys.massfloatSigma[5.5/29.2] Molecular gas surface densitysolMass.pc**-2phot.flux.density.sbfloat13CODisplay the ^13^CO parametersmeta.ref.urlintnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_GlonPositions from MWISP names (longitude part)degpos.galactic.lon_GlatPositions from MWISP 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.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.decnullableindexedJ/ApJS/230/17/table2Molecular clouds marginally detected by this studyNameCloud identifiermeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintVLSR[-69/-48] Local Standard of Rest velocitykm/sphys.veloc;pos.lsrfloat_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.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.decnullableindexedJ/ApJS/230/17/table3Parameters of molecular clouds derived by ^13^CO(1-0)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMWISPCloud identifier (GLL.lll+B.bbb)meta.id;meta.maincharf_MWISP[t] t: sources belong to the same cloud MWISP G37.175+0.792meta.codecharVLSR[-64/-45] Local Standard of Rest velocity (1)km/sphys.veloc;pos.lsrfloate_VLSR[0.04/0.2] VLSR uncertaintykm/sstat.error;phys.veloc;pos.lsrfloatDelV[0.5/4.5] Line width Full-Width at Half-Maximum (1)km/sspect.line.widthfloate_DelV[0.1/0.7] DelV uncertaintykm/sstat.errorfloatInt[0.3/2.8] Integrated ^13^CO intensity (1)K.km/sphot.flux.density;em.line.COfloate_Int[0.06/0.4] Int uncertaintyK.km/sstat.errorfloatTpk[0.3/1.3] Peak intensity (1)Kphot.antennaTempfloat12CO/13CO[2.8/14.3]? Integrated intensity ratio of ^12^C0 and ^13^COspect.line.intensity;arith.ratiofloatnullablerms[0.1/0.3] rms level of each detection with a velocity resolution of 0.166km/s (2)Kstat.stdev;phys.veloc;spect.resolutionfloat12CO1: link to ^12^CO parameters (table 1)meta.ref.urlintnullable_GlonPositions from MWISP names (longitude part)degpos.galactic.lon_GlatPositions from MWISP 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.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