J/A+A/624/A107ivo://CDS.VizieR/J/A+A/624/A107doi:10.26093/cds/vizier.36240107CDSVerbena J.L.Bujarrabal V.Alcolea J.Gomez-Garrido M.Castro-Carrizo A.2019-05-06T15:29:13Z2019-04-23T08:37:19ZCDS support team

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

cds-question@unistra.frlate-type-starsm-starsradio-spectroscopyAGB stars go through a process of strong mass-loss that involves pulsations of the atmosphere, which extends to a region where the conditions are adequate for dust grains to form. Radiation pressure acts on these grains which, coupled to the gas, drive a massive outflow. The details of this process are not clear, including which molecules are involved in the condensation of dust grains. To study the role of the SiO molecule in the process of dust formation and mass-loss in M-type AGB stars. Using the IRAM NOEMA interferometer we observed the ^28^SiO and ^29^SiO J=3-2, v=0 emission from the inner circumstellar envelope of the evolved stars IK Tau and IRC+10011. We computed azimuthally averaged emission profiles to compare the observations to models using a molecular excitation and ray-tracing code for SiO thermal emission. We observed circular symmetry in the emission distribution. We also found that the source diameter varies only marginally with radial velocity, which is not the expected behavior for envelopes expanding at an almost constant velocity. The adopted density, velocity, and abundance laws, together with the mass-loss rate, which best fit the observations, give us information on the chemical behavior of the SiO molecule and its role in the dust formation process. The results indicate that there is a strong coupling between the depletion of gas phase SiO and gas acceleration in the inner envelope. This could be explained by the condensation of SiO into dust grains.2019A&A...624A.107Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/624/A107CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/597/A25 : IK Tau millimeter IRAM-30m line survey (Velilla Prieto+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/624/A107https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/624/A107http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/624/A107https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/624/A107https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/624/A107http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/624/A107GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/624/A107/list (List of datacubes)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/624/A107/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/624/A107/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/624/A107/list?GETtext/xml+votable180.050000true58.370511.405980.0055555555555555566/18364 23471https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/624/A107?format=asciiMillimeterdefaultJ/A+A/624/A107/listList of datacubesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintNzNumber of slicesmeta.numberintRestFreqRest frequencyMHzem.freqdoublebVRADLower value of VRAD intervalm/sphys.veloc;pos.heliocentricintBVRADUpper value of VRAD intervalm/sphys.veloc;pos.heliocentricintdVRADVRAD resolutionm/sspect.resolutionintsizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fits