J/ApJ/788/59ivo://CDS.VizieR/J/ApJ/788/59doi:10.26093/cds/vizier.17880059CDSWilliams J.P.Best W.M.J.2017-09-04T08:04:11Z2017-07-11T07:02:35ZCDS support team

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

cds-question@unistra.frastronomical-modelsstellar-masseseffective-temperatureThe disks that surround young stars are mostly composed of molecular gas, which is harder to detect and interpret than the accompanying dust. Disk mass measurements have therefore relied on large and uncertain extrapolations from the dust to the gas. We have developed a grid of models to study the dependencies of isotopologue CO line strengths on disk structure and temperature parameters and find that a combination of ^13^CO and C^18^O observations provides a robust measure of the gas mass. We apply this technique to Submillimeter Array observations of nine circumstellar disks and published measurements of six well studied disks. We find evidence for selective photodissociation of C^18^O and determine masses to within a factor of about three. The inferred masses for the nine disks in our survey range from 0.7 to 6 M_Jup_, and all are well below the extrapolation from the interstellar medium gas-to-dust ratio of 100. This is consistent with the low masses of planets found around such stars, and may be due to accretion or photoevaporation of a dust-poor upper atmosphere. However, the masses may be underestimated if there are more efficient CO depletion pathways than those known in molecular clouds and cold cores.2014ApJ...788...59Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/788/59CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJ/784/62 : Circumstellar disks around binary stars in Taurushttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/788/59https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/788/59http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/788/59https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/788/59https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/788/59http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/788/59GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/ApJ/788/59/table3Parametric Model OutputrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintM*Stellar mass (0.5, 1.0)solMassphys.massfloatMgasGas mass (0.0001, 0.0003, 0.0010, 0.0030, 0.0100, 0.0300, 0.1000)solMassphys.massfloatgammaSurface density power law index (0.0, 0.8, 1.5)spect.indexfloatRcCharacteristic disk radius (30, 60, 100, 200)AUphys.size.radiusintTmid1Inner midplane temperature (100, 200, 300)Kphys.temperatureintTatm1Inner atmopsheric temperature (500, 750, 1000, 1500)Kphys.temperatureintqRadial power law index (0.45, 0.55, 0.65)phys.refractIndexfloatIncInclination (0, 45, 90)degsrc.orbital.inclinationintffreezeMass fraction where CO is frozen outphys.massfloatfdissocMass fraction where CO is dissociatedphys.massfloatFCO10Integrated intensity of CO J=1-0 lineJy.km/sphot.flux.density;em.line.COfloatFCO21Integrated intensity of CO J=2-1 lineJy.km/sphot.flux.density;em.line.COfloatFCO32Integrated intensity of CO J=3-2 lineJy.km/sphot.flux.density;em.line.COfloatF13CO10Integrated intensity of ^13^CO J=1-0 lineJy.km/sphot.flux.density;em.line.COfloatF13CO21Integrated intensity of ^13^CO J=2-1 lineJy.km/sphot.flux.density;em.line.COfloatF13CO32Integrated intensity of ^13^CO J=3-2 lineJy.km/sphot.flux.density;em.line.COfloatFC18O10Integrated intensity of C^18^O J=1-0 lineJy.km/sphot.flux.densityfloatFC18O21Integrated intensity of C^18^O J=2-1 lineJy.km/sphot.flux.densityfloatFC18O32Integrated intensity of C^18^O J=3-2 lineJy.km/sphot.flux.densityfloatFC18O10lIntegrated intensity limit of low abundance C^18^O J=1-0 lineJy.km/sphot.flux.densityfloatFC18O21lIntegrated intensity limit of low abundance C^18^O J=2-1 lineJy.km/sphot.flux.densityfloatFC18O32lIntegrated intensity limit of low abundance C^18^O J=3-2 lineJy.km/sphot.flux.densityfloat