J/ApJ/678/985ivo://CDS.VizieR/J/ApJ/678/985doi:10.26093/cds/vizier.16780985CDSBoogert A.C.A.Pontoppidan K.M.Knez C.Lahuis F.Kessler-Silacci J.,Van Dishoeck E.F.Blake G.A.Augereau J.-C.Bisschop S.E.,Bottinelli S.Brooke T.Y.Brown J.Crapsi A.Evans N.J.II,Fraser H.J.Geers V.Huard T.L.Jorgensen J.K.Oberg K.I.Allen L.E.,Harvey P.M.Koerner D.W.Mundy L.G.Padgett D.L.Sargent A.I.,Stapelfeldt K.R.2017-07-03T14:25:34Z2010-10-06T15:15:36ZCDS support team

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

cds-question@unistra.fryoung-stellar-objectsinfrared-astronomyspectroscopychemical-abundancesTo study the physical and chemical evolution of ices in solar-mass systems, a spectral survey is conducted of a sample of 41 low-luminosity YSOs (L~0.1-10L_{sun}_) using 3-38um Spitzer and ground-based spectra. The sample is complemented with previously published Spitzer spectra of background stars and with ISO spectra of well-studied massive YSOs (L~10^5^L_{sun}_). The long-known 6.0 and 6.85um bands are detected toward all sources, with the Class 0-type YSOs showing the deepest bands ever observed. The 6.0um band is often deeper than expected from the bending mode of pure solid H_2_O. The additional 5-7um absorption consists of five independent components, which, by comparison to laboratory studies, must be from at least eight different carriers. Much of this absorption is due to simple species likely formed by grain surface chemistry, at abundances of 1%-30% for CH_3_OH, 3%-8% for NH_3_, 1%-5% for HCOOH, ~6% for H_2_CO, and ~0.3% for HCOO- relative to solid H_2_O. The 6.85um band has one or two carriers, of which one may be less volatile than H_2_O. Its carrier(s) formed early in the molecular cloud evolution and do not survive in the diffuse ISM. If an NH_4_^+^ -containing salt is the carrier, its abundance relative to solid H_2_O is ~7%, demonstrating the efficiency of low-temperature acid-base chemistry or cosmic-ray-induced reactions. Possible origins are discussed for enigmatic, very broad absorption between 5 and 8um. Finally, the same ices are observed toward massive and low-mass YSOs, indicating that processing by internal UV radiation fields is a minor factor in their early chemical evolution.2008ApJ...678..985Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/678/985CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/86/713 : IR spectroscopy of ices (Hudgins+, 1993)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/678/985https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/678/985http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/678/985https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/678/985https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/678/985http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/678/985GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/678/985/H2Osample (Sample, fit parameters and column densities of the ices)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/678/985/H2Osample?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/678/985/H2Osample?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/678/985/H2Osample?GETtext/xml+votable180.050000true51.289333330.77269440.0055555555555555566/857 858 859 860 862 881 1054 1061 1074 1154 1159 1542 3649 14317 15426 15667 15857 21458 23637 29101 29193 29504 30241 30366 30733 37819 41132 42738 42981 43444 47742 47828https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/678/985?format=asciiInfrareddefaultJ/ApJ/678/985/H2OsampleSample, fit parameters and column densities of the icesCloudIDName of cloudmeta.id.parentchartypeSource type (3)src.classcharl_E6Limit flag on E6meta.code.errorcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource namemeta.id;meta.maincharr_Name[h-m ] Previous reference (1)meta.ref;pos.framecharONameAliasmeta.notecharRAJ2000Hour of right ascension (J2000) (2)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000) (2)pos.eq.dec;meta.mainalpha? Brodband {alpha} spectral index (4)spect.indexfloatnullablef_alpha[g] Remarks on alpha (5)meta.codecharObsIDKey for Spitzer of ISO observations (6)meta.ref;pos.framecharModuleSpitzer IRS modules used (7)instr.setupcharLbandComplementary observations in L-band (8)meta.id;instrcharSimbadNameSimbad column added by the CDSmeta.idcharTThe H_2_O temperature (1)Kphys.temperatureintq_T[*] most accurate temperature (2)meta.code.qualcharE6The 6 micron excess; as defined in Eq. 2phot.color.excessfloate_E6? Statistical error in E6 (3)stat.errorfloatnullabletau9.7? Peak optical depth at 9.7 microns (4)phys.absorption.opticalDepth;stat.maxfloatnullablee_tau9.7? Statistical error in tau9.7 (5)stat.errorfloatnullabletau6Peak optical depth at 6.0 microns (6)phys.absorption.opticalDepth;stat.maxfloate_tau6Statistical error in tau6.0stat.errorfloattauC1Peak optical depth component C1phys.absorption.opticalDepth;stat.maxfloate_tauC1Statistical error in tauC1stat.errorfloattauC2Peak optical depth component C2phys.absorption.opticalDepth;stat.maxfloate_tauC2Statistical error in tauC2stat.errorfloattauC3Peak optical depth component C3phys.absorption.opticalDepth;stat.maxfloate_tauC3Statistical error in tauC3stat.errorfloattauC4Peak optical depth component C4phys.absorption.opticalDepth;stat.maxfloate_tauC4Statistical error in tauC4stat.errorfloattauC5Peak optical depth component C5phys.absorption.opticalDepth;stat.maxfloate_tauC5Statistical error in tauC5 (7)stat.errorfloatRef[a-t, ] Reference(s) for column density values (1)meta.ref;pos.framecharl_NH2OLimit flag on NH20 (2)meta.code.errorcharNH2OH_2_0 column density1e+18cm**-2phys.columnDensityfloate_NH2O? NH20 uncertainty1e+18cm**-2stat.errorfloatnullablef_NH2O[c] Flag on NH20 (3)meta.codecharl_NHCOOH[<= ] Limit flag on NHCOOH (2)meta.code.errorcharNHCOOH? HCOOH column density in percentage of H_2_O (4)%phys.columnDensityfloatnullablee_NHCOOH? NHCOOH uncertainty%stat.errorfloatnullablel_NCH3OHLimit flag on NCH3OH (2)meta.code.errorcharNCH3OH? CH_3_OH column density in percentage of H_2_O%phys.columnDensityfloatnullablee_NCH3OH? NCH3OH uncertainty%stat.errorfloatnullablef_NCH3OH[d] Flag on NCH3OH (5)meta.codecharNNH4? NH_4_^+^ column density in percentage of H_2_O (6)%phys.columnDensityfloatnullablee_NNH4? NNH4 uncertainty%stat.errorfloatnullable