J/ApJ/764/34ivo://CDS.VizieR/J/ApJ/764/34doi:10.26093/cds/vizier.17640034CDSWenger T.V.Bania T.M.Balser D.S.Anderson L.D.2017-09-29T09:02:57Z2014-11-14T10:40:05ZCDS support team

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

cds-question@unistra.frh-ii-regionsinterstellar-mediumsurveysradio-astronomyThe Green Bank Telescope H II Region Discovery Survey (GBT HRDS) found hundreds of previously unknown Galactic regions of massive star formation by detecting hydrogen radio recombination line (RRL) emission from candidate H II region targets. Since the HRDS nebulae lie at large distances from the Sun, they are located in previously unprobed zones of the Galactic disk. Here, we derive the properties of helium and carbon RRL emission from HRDS nebulae. Our target sample is the subset of the HRDS that has visible helium or carbon RRLs. This criterion gives a total of 84 velocity components (14% of the HRDS) with helium emission and 52 (9%) with carbon emission. For our highest quality sources, the average ^4^He^+^/H^+^ abundance ratio by number, <y^+^>, is 0.068+/-0.023(1{sigma}). This is the same ratio as that measured for the sample of previously known Galactic H II regions. Nebulae without detected helium emission give robust y^+^ upper limits. There are 5 RRL emission components with y^+^ less than 0.04 and another 12 with upper limits below this value. These H II regions must have either a very low ^4^He abundance or contain a significant amount of neutral helium. The HRDS has 20 nebulae with carbon RRL emission but no helium emission at its sensitivity level. There is no correlation between the carbon RRL parameters and the 8um mid-infrared morphology of these nebulae.2013ApJ...764...34Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/764/34CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/58 : A Survey of Radio H II Regions in the Northern Sky (Lockman+ 1989)J/ApJ/754/62 : HRDS III. HII region kinematic distances (Anderson+, 2012)J/ApJS/194/32 : The HII Region Discovery Survey (HRDS). II. (Anderson+, 2011)J/ApJ/738/27 : Galactic HII regions RRL and continuum data (Balser+, 2011)J/ApJ/690/706 : Distances of Galactic HII regions (Anderson+, 2009)J/ApJ/670/428 : Bubbles in the galactic disk. II. (Churchwell+, 2007)J/ApJ/649/759 : Bubbles in the galactic disk (Churchwell+, 2006)J/ApJ/653/1226 : Physical properties of galactic HII regions (Quireza+, 2006)J/ApJS/165/338 : Radio recombination lines in HII regions (Quireza+, 2006)http://www.cv.nrao.edu/hrds/ : The GBT HRDS home pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/764/34https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/764/34http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/764/34https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/764/34https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/764/34http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/764/34GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/764/34/table1 (Hydrogen Radio Recombination Line parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/764/34/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/764/34/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/764/34/table1?GETtext/xml+votable180.050000true266.615-28.6011110.0055555555555555566/12974 28808 28809 28812 28824 28826 28830 28831 28874 28900 28901 28915 28919 29090 29091 29097 29115 29118 29119 29504 29505 29508 29511 29532 29533 30218 30245 30256 30258 30262 30263 30268 30312 30314 30318 30319 30420 30421 30423 30594 30604 30605 30618 30619 30644 30691 30694 30701 30715 42390 42392 42397 42436 42441 42445 42454 42457 42458https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/764/34?format=asciiRadiodefaultJ/ApJ/764/34/table1Hydrogen Radio Recombination Line parametersCCarbon RRL parameters, if anymeta.numberintnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHeHelium RRL parameters, if anymeta.numberintnullableHRDSSource identification (GLLL.lll+B.bbb)meta.id;meta.maincharm_HRDSMultiple velocity component (1)meta.code.multipcharTL[2/280] Line intensity (T_L_)mKphot.antennaTempfloate_TL[0.1/18] Fit uncertainty of TLmKstat.errorfloatFWHM[2/40] FWHM line width ({Delta}V)km/sspect.line.widthfloate_FWHM[0.04/7] Fit uncertainty of FWHMkm/sstat.error;phys.angSizefloatVLSR[-216/117] Line LSR velocity (V_LSR_)km/sphys.veloc;pos.lsrfloate_VLSR[0.03/5] Fit uncertainty of VLSRkm/sstat.error;phys.veloc;pos.lsrfloatrms[0.9/3.4] rms spectral noise in the baseline regionsmKstat.stdev;instr.det.noisefloatQF[ABC] Quality factor (A: highest quality) (2)arith.factorcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPositions from Paper II (Anderson et al. 2011, J/ApJS/194/32) (right ascension part)degpos.eq.ra;meta.main_DEPositions from Paper II (Anderson et al. 2011, J/ApJS/194/32) (declination part)degpos.eq.dec;meta.mainJ/ApJ/764/34/table2Helium Radio Recombination Line parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHRDSSource identification (GLLL.lll+B.bbb)meta.id;meta.maincharm_HRDSMultiple velocity component (1)meta.code.multipcharTL[2/280] Line intensity (T_L_)mKphot.antennaTempfloate_TL[0.1/18] Fit uncertainty of TLmKstat.errorfloatFWHM[2/40] FWHM line width ({Delta}V)km/sspect.line.widthfloate_FWHM[0.04/7] Fit uncertainty of FWHMkm/sstat.error;phys.angSizefloatVLSR[-216/117] Line LSR velocity (V_LSR_)km/sphys.veloc;pos.lsrfloate_VLSR[0.03/5] Fit uncertainty of VLSRkm/sstat.error;phys.veloc;pos.lsrfloatrms[0.9/3.4] rms spectral noise in the baseline regionsmKstat.stdev;instr.det.noisefloatQF[ABC] Quality factor (A: highest quality) (2)arith.factorcharJ/ApJ/764/34/table3Carbon Radio Recombination Line parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHRDSSource identification (GLLL.lll+B.bbb)meta.id;meta.maincharm_HRDSMultiple velocity component (1)meta.code.multipcharn_HRDS[a] a: carbon, but no helium radio recombination emission (only for table 3)meta.notecharTL[2/280] Line intensity (T_L_)mKphot.antennaTempfloate_TL[0.1/18] Fit uncertainty of TLmKstat.errorfloatFWHM[2/40] FWHM line width ({Delta}V)km/sspect.line.widthfloate_FWHM[0.04/7] Fit uncertainty of FWHMkm/sstat.error;phys.angSizefloatVLSR[-216/117] Line LSR velocity (V_LSR_)km/sphys.veloc;pos.lsrfloate_VLSR[0.03/5] Fit uncertainty of VLSRkm/sstat.error;phys.veloc;pos.lsrfloatrms[0.9/3.4] rms spectral noise in the baseline regionsmKstat.stdev;instr.det.noisefloatQF[ABC] Quality factor (A: highest quality) (2)arith.factorchar