J/ApJ/935/165ivo://CDS.VizieR/J/ApJ/935/165doi:10.26093/cds/vizier.19350165CDSBarr A.G.Boogert A.Li J.DeWitt C.N.Montiel E.Richter M.J.,Indriolo N.Pendleton Y.Chiar J.Tielens A.G.G. M2024-11-06T20:26:41Z2024-06-24T11:35:38ZCDS support team

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

cds-question@unistra.frstar-forming-regionsyoung-stellar-objectsinfrared-astronomyspectroscopyWe have performed a high-resolution 4-13{mu}m spectral survey of the hot molecular gas associated with the massive protostars AFGL-2591 and AFGL-2136. Here we present the results of the analysis of the {nu}2 band of H2O, detected with the Echelon Cross Echelle Spectrograph on board the Stratospheric Observatory for Infrared Astronomy between wavelengths of 5 and 8{mu}m. All lines are seen in absorption. Rotation diagrams indicate that the gas is optically thick and lines are observed to saturate at 40% and 15% relative to the continuum for AFGL 2136 and AFGL 2591, respectively. We applied two curve of growth analyses to derive the physical conditions, one assuming a foreground origin and one a circumstellar disk origin. We find temperatures of 400-600K. A foreground origin would require the presence of externally heated clumps that are smaller than the continuum source. The disk analysis is based on stellar atmosphere theory, which takes into consideration the temperature gradient in the disk. We discuss the challenges with each model, taking into consideration the properties of other species detected in the spectral survey, and conclude that further modeling efforts are required to establish whether the absorption has a disk or foreground origin. The main challenge to the foreground model is that molecules are expected to be observed in emission. The main challenges to the disk model are the midplane heating mechanism and the presence of narrow absorption lines shifted from the systemic velocity.2022ApJ...935..165Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/935/165CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJ/606/L73 : CO emission of 5 Herbig Ae stars (Blake+, 2004)J/A+A/492/257 : Collisional excitation of water in warm media (Faure+, 2008)J/ApJ/696/471 : MIR spectroscopy of NGC 7538 IRS 1 (Knez+, 2009)J/A+A/558/A24 : The VLTI/MIDI survey of Massive YSOs (Boley+, 2013)J/A+A/620/A31 : ALMA maps of G17.64+0.16 (Maud+, 2018)J/A+A/627/L6 : ALMA Long Baseline maps of G17.64+0.16 (Maud+, 2019)J/ApJ/900/104 : IR high-res. sp. hot cores of AFGL2591 & AFGL2136 (Barr+, 2020)J/A+A/655/A84 : AFGL 2591-VLA 3 IRAM/NOEMA datacubes (Suri+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/935/165https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/935/165http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/935/165https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/935/165https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/935/165http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/935/165GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfrareddefaultJ/ApJ/935/165/table4*Line Parameters for the v=1-0 transition of AFGL 2136recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTransTransitionmeta.id;phys.atmol.transitioncharWaveWavelengthumem.wlfloatElLower level energyKphys.energy;phys.atmol.levelintglLower level statistical weightstat.weight;phys.atmol.levelintguUpper level statistical weightstat.weight;phys.atmol.levelintAulEinstein coefficients**-1phys.atmol.transProbfloatVLSRPeak line Local Standard of Rest velocitykm/sphys.veloc;pos.lsrfloate_VLSRUncertainty in VLSRkm/sstat.error;phys.veloc;pos.lsrfloatFWHMFull-Width at Half Maximum of linekm/sspect.line.widthfloate_FWHMUncertainty in FWHMkm/sstat.error;phys.angSizefloatEWEquivalent width of line1e+08Hzspect.line.eqWidthfloate_EWUncertainty in W1e+08Hzstat.error;spect.line.eqWidthfloatlogeta0log lower level opacity (1)phys.absorption.coefffloatlogtau0log peak optical depthphys.absorption.opticalDepth;stat.maxfloatJ/ApJ/935/165/table5*Line Parameters for the v=2-1 transition of AFGL 2136recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTransTransitionmeta.id;phys.atmol.transitioncharWaveWavelengthumem.wlfloatElLower level energyKphys.energy;phys.atmol.levelintglLower level statistical weightstat.weight;phys.atmol.levelintguUpper level statistical weightstat.weight;phys.atmol.levelintAulEinstein coefficients**-1phys.atmol.transProbfloatVLSRPeak line Local Standard of Rest velocitykm/sphys.veloc;pos.lsrfloate_VLSRUncertainty in VLSRkm/sstat.error;phys.veloc;pos.lsrfloatFWHMFull-Width at Half Maximum of linekm/sspect.line.widthfloate_FWHMUncertainty in FWHMkm/sstat.error;phys.angSizefloatEWEquivalent width of line1e+08Hzspect.line.eqWidthfloate_EWUncertainty in W1e+08Hzstat.error;spect.line.eqWidthfloatlogeta0log lower level opacity (1)phys.absorption.coefffloatlogtau0log peak optical depthphys.absorption.opticalDepth;stat.maxfloatJ/ApJ/935/165/table7*Line Parameters for the v=1-0 transition of AFGL 2591recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTransTransitionmeta.id;phys.atmol.transitioncharWaveWavelengthumem.wlfloatElLower level energyKphys.energy;phys.atmol.levelintglLower level statistical weightstat.weight;phys.atmol.levelintguUpper level statistical weightstat.weight;phys.atmol.levelintAulEinstein coefficients**-1phys.atmol.transProbfloatVLSRPeak line Local Standard of Rest velocitykm/sphys.veloc;pos.lsrfloate_VLSRUncertainty in VLSRkm/sstat.error;phys.veloc;pos.lsrfloatFWHMFull-Width at Half Maximum of linekm/sspect.line.widthfloate_FWHMUncertainty in FWHMkm/sstat.error;phys.angSizefloatEWEquivalent width of line1e+08Hzspect.line.eqWidthfloate_EWUncertainty in W1e+08Hzstat.error;spect.line.eqWidthfloatlogeta0log lower level opacity (1)phys.absorption.coefffloatlogtau0log peak optical depthphys.absorption.opticalDepth;stat.maxfloatJ/ApJ/935/165/table8*Line Parameters for the v=2-1 transition of AFGL 2591recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTransTransitionmeta.id;phys.atmol.transitioncharWaveWavelengthumem.wlfloatElLower level energyKphys.energy;phys.atmol.levelintglLower level statistical weightstat.weight;phys.atmol.levelintguUpper level statistical weightstat.weight;phys.atmol.levelintAulEinstein coefficients**-1phys.atmol.transProbfloatVLSRPeak line Local Standard of Rest velocitykm/sphys.veloc;pos.lsrfloate_VLSRUncertainty in VLSRkm/sstat.error;phys.veloc;pos.lsrfloatFWHMFull-Width at Half Maximum of linekm/sspect.line.widthfloate_FWHMUncertainty in FWHMkm/sstat.error;phys.angSizefloatEWEquivalent width of line1e+08Hzspect.line.eqWidthfloate_EWUncertainty in W1e+08Hzstat.error;spect.line.eqWidthfloatlogeta0log lower level opacity (1)phys.absorption.coefffloatlogtau0log peak optical depthphys.absorption.opticalDepth;stat.maxfloat