J/PASJ/73/487ivo://CDS.VizieR/J/PASJ/73/487doi:10.26093/cds/vizier/bj-29-f7CDSTakemura H.Nakamura F.Ishii S.Shimajiri Y.Sanhueza P.,Tsukagoshi T.Kawabe R.Hirota T.Kataoka A.2026-03-17T20:05:55Z2021-10-01T13:37:31ZCDS support team

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

cds-question@unistra.frmolecular-cloudsinterstellar-mediumgalaxy-classification-systemsWe have performed an unbiased dense core survey toward the Orion A Giant Molecular Cloud in the C^18^O (J=1-0) emission line taken with the Nobeyama Radio Observatory (NRO) 45 m telescope. The effective angular resolution of the map is 26", which corresponds to ~0.05pc at a distance of 414pc. By using the Herschel-Planck H_2_ column density map, we calculate the C^18^O fractional abundance and find that it is roughly constant over the column density range of <~5x10^22^cm^-3^, although a trend of C^18^O depletion is determined toward higher column density. Therefore, C^18^O intensity can follow the cloud structure reasonably well. The mean C^18^O abundance in Orion A is estimated to be 5.7x10^-7^, which is about three times larger than the fiducial value. We identified 746 C^18^O cores with astrodendro and classified 709 cores as starless cores. We compute the core masses by decomposing the Herschel-Planck dust column density using the relative proportions of the C^18^O integrated intensities of line-of-sight components. Applying this procedure, we attempt to remove the contribution of the background emission, i.e., the ambient gas outside the cores. Then, we derived mass function for starless cores and found that it resembles the stellar initial mass function (IMF). The CMF for starless cores, dN/dM, is fitted with a power-law relation of M^{alpha}^ with a power index of {alpha}=-2.25+/-0.16 at the high-mass slope (>~0.44M_{sun}_). We also found that the ratio of each core mass to the total mass integrated along the line of sight is significantly large. Therefore, in the previous studies, the core masses derived from the dust image are likely to be overestimated by at least a factor of a few. Accordingly, such previous studies may underestimate the star formation efficiency of individual cores.2021PASJ...73..487Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/PASJ/73/487CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/665/1194 : Dense cores in the Orion A cloud survey (Ikeda+, 2007)J/ApJ/846/144 : Virial analysis of the dense cores in Orion A (Kirk+, 2017)J/ApJS/217/7 : Orion A dense cores based on 1.1mm and C^18^Ohttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/PASJ/73/487https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/PASJ/73/487http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/PASJ/73/487https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/PASJ/73/487https://vizier.iucaa.in/viz-bin/votable?-source=J/PASJ/73/487http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/PASJ/73/487GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/PASJ/73/487/table3 (Properties of identified cores)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/PASJ/73/487/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/PASJ/73/487/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/PASJ/73/487/table3?GETtext/xml+votable180.050000true83.43625-5.3013890.0055555555555555566/21436 21438-21439 22804-22805https://cdsarc.cds.unistra.fr/viz-bin/moc/J/PASJ/73/487?format=asciiOpticaldefaultJ/PASJ/73/487/table3Properties of identified coresrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/746] Sequential numbermeta.id;meta.mainintRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainvLSRLSR velocitykm/sphys.veloc;pos.lsrfloatAreaExact area of the core projected on to the plane of the skyarcsec**2phys.areaint2RcoreAngular core diameterarcsecphys.angSizeint2RcorepcLinear core diameterpcphys.size.diameterfloatamajorSemi-major axisarcsecphys.angSize;srcfloataminorSemi-minor axisarcsecphys.angSize.sminAxisfloatPA[] Position angledegpos.posAngintdVcoreFWHM velocity widthkm/sinstr.bandwidthfloatYSO[Y/N] YSO ?meta.codecharJ/PASJ/73/487/table4Properties of identified coresrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/746] Sequential numbermeta.id;meta.mainintTpeakmbPeak temperatureKphys.temperaturefloatTtotalmbTotal temperatureKphys.temperaturefloatMcoreCore masssolMassphys.massfloatMvir/McoreVirial ratio, Mvir/Mcorephys.mass;arith.ratiofloatnMean number density10000cm**-2phys.densityfloatTexMean excitation temperatureKphys.atmol.excitation;stat.meanfloatNC18OMean column density of C^18^O1e+15cm**-2phys.columnDensity;stat.meanfloatXC18OMean fractional abundance of C^18^Ophys.abundfloat