J/ApJ/720/259ivo://CDS.VizieR/J/ApJ/720/259doi:10.26093/cds/vizier.17200259CDSWhittet D.C.B.Goldsmith P.F.Pineda J.L.2017-10-09T13:34:37Z2012-07-12T13:54:01ZCDS support team

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

cds-question@unistra.frmolecular-cloudsextinctionchemical-abundancesinterstellar-mediumradio-astronomyData from the Five College Radio Astronomy Observatory CO Mapping Survey of the Taurus molecular cloud are combined with extinction data for a sample of 292 background field stars to investigate the uptake of CO from the gas to icy grain mantles on dust within the cloud. On the assumption that the reservoir of CO in the ices is represented well by the combined abundances of solid CO and solid CO_2_ (which forms by oxidation of CO on the dust), we find that the total column density (gas+solid) correlates tightly with visual extinction (A_V_) over the range 5mag<A_V_<30mag, i.e., up to the highest extinctions covered by our sample. The mean depletion of gas-phase CO, expressed as {delta}(CO)=N(CO)_ice_/N(CO)_total_, increases monotonically from negligible levels for A_V_<~5 to ~0.3 at A_V_=10 and ~0.6 at A_V_=30. As these results refer to line-of-sight averages, they must be considered lower limits to the actual depletion at loci deep within the cloud, which may approach unity. We show that it is plausible for such high levels of depletion to be reached in dense cores on timescales ~0.6Myr, comparable with their expected lifetimes. Dispersal of cores during star formation may be effective in maintaining observable levels of gaseous CO on the longer timescales estimated for the age of the cloud.2010ApJ...720..259Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/720/259CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)J/ApJS/176/457 : Taurus dark cloud background star catalog (Shenoy+, 2008)J/ApJ/678/985 : c2d Spitzer survey of interstellar ices. I. (Boogert+, 2008)J/A+A/421/1087 : CO abundance of 3 globules (Harjunpaa+, 2004)J/ApJ/517/264 : Extinction in the Taurus dark cloud complex (Arce+, 1999)J/ApJS/101/117 : UBVRIJHKLMNQ photometry in Taurus-Auriga (Kenyon+ 1995)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/720/259https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/720/259http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/720/259https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/720/259https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/720/259http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/720/259GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/720/259/table1 (Extinction values and column densities for program stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/720/259/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/720/259/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/720/259/table1?GETtext/xml+votable180.050000true62.111383328.06193890.0055555555555555565/259 262 263 270 272 6/375 1031 1042 1043 1044 1046 1047 1059 1060 1061 1063 1065 1066 1068 1069 1073 1074 1075 1076 1078 1079 1084 1085 1096 1097 1098 1102 1122 1129 1159 1164 1165 1168 1169 1170 1176 1178 24299https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/720/259?format=asciiRadiodefaultJ/ApJ/720/259/table1Extinction values and column densities for program starsSimbadNameSimbad column added by the CDSmeta.idcharSeq[1/302] Running numbermeta.id;meta.mainintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSource identification (1)meta.idcharA(V)Visual extinctionmagphys.absorption;em.opt.VfloatN(CO)gasGas phase CO column density (2)1e+17cm**-2phys.columnDensityfloatN(CO)ice? Solid phase CO column density (3)1e+17cm**-2phys.columnDensityfloatnullableN(CO2)ice? Solid phase CO2 column density (3)1e+17cm**-2phys.columnDensityfloatnullable2MDisplay the 2MASS data within 1.5" (Cutri et al. 2003, Cat. II/246)meta.ref.urlchar_RAPositions from 2MASS (Cat. II/246) or SIMBAD (right ascension part)degpos.eq.ra;meta.main_DEPositions from 2MASS (Cat. II/246) or SIMBAD (declination part)degpos.eq.dec;meta.main