J/ApJS/268/56ivo://CDS.VizieR/J/ApJS/268/56doi:10.26093/cds/vizier.22680056CDSZou Y.P.Zhang J.S.Henkel C.Romano D.Liu W.Zheng Y.H.Yan Y.T.,Chen J.L.Wang Y.X.Zhao J.Y.2024-11-06T20:30:07Z2024-02-09T08:20:29ZCDS support team

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

cds-question@unistra.frco-line-emissionmolecular-cloudsmilky-way-galaxyinterstellar-mediumTo investigate the relative amount of ejecta from high-mass versus intermediate-mass stars and to trace the chemical evolution of the Galaxy, we have performed a systematic study of Galactic interstellar ^18^O/^17^O ratios toward a sample of 421 molecular clouds with IRAM-30m and the 10m Submillimeter Telescope, covering a galactocentric distance range of ~1-22kpc. The results presented in this paper are based on the J=2-1 transition and encompass 364 sources showing both C^18^O and C^17^O detections. The previously suggested ^18^O/^17^O gradient is confirmed. For the 41 sources detected with both facilities, good agreement is obtained. A correlation of the ^18^O/^17^O ratios with heliocentric distance is not found, indicating that beam dilution and linear beam sizes are not relevant. For the subsample of IRAM 30m high-mass star-forming regions with accurate parallax distances, an unweighted fit gives ^18^O/^17^O=(0.12+/-0.02)RGC+(2.38+/-0.13) with a correlation coefficient of R=0.67. While the slope is consistent with our J=1-0 measurement, the ratios are systematically lower. This should be caused by larger optical depths of C^18^O 2-1 lines with respect to the corresponding 1-0 transitions, which is supported by RADEX calculations and the fact that C18O/C17O is positively correlated with ^13^CO/C^18^O. When we consider that optical depth effects with C^18^O(J=2-1) typically reach an optical depth of ~0.5, the corrected ^18^O/^17^O ratios from the J=1-0 and J=2-1 lines are consistent. A good numerical fit to the data is provided by the MWG-12 model, which includes both rotating stars and novae.2023ApJS..268...56Zhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/268/56CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+AS/80/149 : IRAS Sources behind the Solar circle (Wouterloot+ 1989)J/A+A/430/549 : C^18^O/C^17^O near rho Oph (Wouterloot+, 2005)J/ApJ/724/748 : Galactic anticenter PNe and oxygen abundance (Henry+, 2010)J/ApJ/741/110 : The BGPS. VII. Massive star-forming regions (Dunham+, 2011)J/MNRAS/418/1689 : Red MSX water maser and ammonia emissions (Urquhart+, 2011)J/A+A/544/A146 : ATLASGAL cold high-mass clumps with NH_3_ (Wienen+, 2012)J/ApJ/764/61 : H2O maser & NH_3_ survey of GLIMPSE EGOs (Cyganowski+, 2013)J/ApJ/783/130 : Parallaxes of high mass star forming regions (Reid+, 2014)J/ApJS/219/28 : C^18^O/C^17^O ratios in the Galactic center (Zhang+, 2015)J/ApJ/822/59 : BGPS. XIV. Molecular cloud clumps GBT obs. (Svoboda+, 2016)J/ApJS/237/13 : Models & yields of massive stars (Limongi+, 2018)J/MNRAS/490/2779 : Dust clumps assoc. with methanol masers (Billington+, 2019)J/ApJ/885/131 : High-mass SFR plx & proper motion with VLBI (Reid+, 2019)J/ApJ/877/154 : H_2_CO TMRT obs. of Galactic molecular clouds (Yan+, 2019)J/A+A/642/A222 : CS isotopes towards Galactic centre clouds (Humire+, 2020)J/ApJ/899/145 : Sulfur isotopes in SFR with 12m ARO and 30m IRAM (Yu+, 2020)J/ApJS/249/6 : Galactic interstellar ratio ^18^O/^17^O. I. (Zhang+, 2020)J/ApJS/257/39 : NH3 isotope ratios of Galactic disk sources (Chen+, 2021)J/A+A/649/A21 : ATLASGAL deuteration of ammonia (Wienen+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/268/56https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/268/56http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/268/56https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/268/56https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/268/56http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/268/56GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/268/56/table1 (Observational parameters and ^18^O/^17^O isotope ratios toward 420 molecular clouds)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/268/56/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/268/56/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/268/56/table1?GETtext/xml+votable180.050000true0.67208364.5677810.0055555555555555565/3576-3577 7383 6/1307 1330 1335 1340 1470 1781 1929 1960 1962 2973 3011 3023 3028 3031 3052 3059 3061 3067-3068 3157 3188 3195 3198 3229 3262 3268-3269 3271 3282-3283 3285 3288 3290 3292 3301-3305 3308 3311 3320 3336 3338 3459 3606 3637 3639-3640 3649 3656 3713 3716-3717 3728-3730 3732 3736 3746 3751 3760 14062-14063 14206 14219 14241 14250-14251 14255 14267 14269-14270 14280 14282 14285 14287 14290 14293-14294 14297-14299 14302-14303 14312 14314 14316-14317 14323 14329 14331 14333 14353-14356 14594 14604 14611 14618 14621-14622 14625-14626 14640 14643 14655 14671 14674 14689 14692 14704 14719 15376-15377 15385-15386 15388 15390 15394 15405 15408-15409 15414 15421 15425 15428-15430 15434-15435 15439 15449 15452 15455 15457-15458 15460-15462 15464 15473-15474 15476-15477 15479 15567 15624 15626-15627 15629 15632 15636 15642 15649 15652 15655 15665 15667-15668 15671 15673 15676 15681-15683 15686 15692 15696-15697 15703 15720 15759 15817 21439 21458 21510 21542 22082 22212 22243 22855 23644 23760 23764 23767 23775 23795 23945 23968-23969 23982 24325 24362 24499 24507 24554 28825 28827 28830-28831 28875 28912-28913 28917-28919 29091-29092 29094 29096-29097 29100-29101 29103 29113-29114 29116 29118 29154 29160 29461 29504 29510 29513 29529 30218-30219 30245 30256 30258-30259 30262-30263 30268-30269 30313 30315 30317-30319 30328 30330 30405 30416 30420 30425 30595 30600-30601 30604 30616-30618 30622 30644 30691-30692 30694 30715 30719 39375 39895 39905 40612 42457https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/268/56?format=asciiRadiodefaultJ/ApJS/268/56/table1Observational parameters and ^18^O/^17^O isotope ratios toward 420 molecular cloudsSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBothIf >=4, both IRAM 30m and SMT 10m results are availablemeta.code.multipintnullableNameSource Name (GBBB.bb+LL.ll or WB89 NNNA)meta.id;meta.maincharm_NameComponent on source name for G123.06-06.30meta.code.multipcharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainRGC[0.3/22.6]? Galactocentric distancekpcpos.distance;pos.galactocentricfloatnullableDist[0.1/20.5]? Heliocentric distancekpcpos.distance;pos.heliocentricfloatnullableTelTelescope used ("IRAM" or "SMT")meta.id;instr.telcharLineLine ("C18O" or "C17O")meta.id;spect.linecharrms[9/750]? Root-mean-square value; in units of TmbmKstat.errorintnullableVpeak[-102/121]? Velocity of the peak Tmbkm/sphys.velocdoublenullablee_Vpeak[0/0.5]? Uncertainty in Vpeakkm/sstat.error;phys.velocfloatnullableFWHM[0.6/18.8]? FWHMkm/sspect.line.widthfloatnullablee_FWHM[0.001/1.1]? Uncertainty in FWHMkm/sstat.error;spect.line.widthfloatnullableTmbdv[0.06/181]? Integrated line intensityK.km/sspect.line.intensityfloatnullablee_Tmbdv[0.008/2.7]? Uncertainty in TmbdvK.km/sstat.error;spect.line.intensityfloatnullableTpeak[0.03/21.7]? Antenna temperature at Tmb peakKphot.antennaTempfloatnullableRcorr[1.2/9.6]? Frequency-corrected abundance ratiophys.abund;arith.ratiofloatnullablee_Rcorr[0.008/2]? Uncertainty in Rcorrstat.error;phys.abund;arith.ratiofloatnullablePapISource also in Paper I (Zhang+, 2020, J/ApJS/249/6/)meta.ref.urlintnullable