J/A+A/640/A74ivo://CDS.VizieR/J/A+A/640/A74doi:10.26093/cds/vizier.36400074CDSSpezzano S.Codella C.Podio L.Ceccarelli C.Caselli P.Neri R.,Lopez-Sepulcre A.2020-11-02T07:42:50Z2020-08-13T07:49:27ZCDS support team

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

cds-question@unistra.frradio-astronomyradio-spectroscopyContrary to what is expected from models of Galactic chemical evolution (GCE), the isotopic fractionation of silicon (Si) in the Galaxy has been recently found to be constant. This finding calls for new observations, also at cores scales, to re-evaluate the fractionation of Si. L1157-B1 is one of the outflow shocked regions along the blue-shifted outflow driven by the Class 0 protostar L1157-mm, and is an ideal laboratory to study the material ejected from the grains in very short timescales, i.e. its chemical composition is representative of the composition of the grains. We imaged ^28^SiO, ^29^SiO and ^30^SiO J = 2-1 emission towards L1157-B1 and B0 with the NOrthern Extended Millimeter Array (NOEMA) interferometer as part of the Seeds of Life in Space (SOLIS) large project. We present here a study of the isotopic fractionation of SiO towards L1157-B1. Furthermore, we use the high spectral resolution observations on the main isotopologue, ^28^SiO, to study the jet impact on the dense gas. We present here also single-dish observations obtained with the IRAM 30m telescope and Herschel-HIFI. We carried out a non-LTE analysis using a Large Velocity Gradient (LVG) code to model the single-dish observations. From our observations we can show that (i) the (2-1) transition of the main isotopologue is optically thick in L1157-B1 even at high velocities, and (ii) the [^29^SiO/^30^SiO] ratio is constant across the source, and consistent with the solar value of 1.5. We report the first isotopic fractionation maps of SiO in a shocked region and show the absence of a mass dependent fractionation in ^29^Si and ^30^Si across L1157-B1. A high-velocity bullet in ^28^SiO has been identified, showing the signature of a jet impacting on the dense gas. With the dataset presented in this paper, both interferometric and single-dish, we were able to study in great detail the gas shocked at the B1a position and its surrounding gas.2020A&A...640A..74Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/640/A74CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/605/A57 : SOLIS. I. OMC2-FIR4 HC_3_N and HC_5_N images (Fontani+, 2017)J/A+A/605/L3 : SOLIS. II. L1157-B1 NH_2_CHO image (Codella+, 2017)J/A+A/640/A75 : SOLIS. X. NGC 1333 IRAS 4A images (De Simone+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/640/A74https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/640/A74http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/640/A74https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/640/A74https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/640/A74http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/640/A74GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/640/A74/list (List of fits datacubes)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/640/A74/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/640/A74/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/640/A74/list?GETtext/xml+votable180.050000true309.7924768.019550.0055555555555555566/15965https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/640/A74?format=asciiRadiodefaultJ/A+A/640/A74/listList of fits 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 pixels along Z-axismeta.numberintbVRADLower value of VRAD intervalm/sphys.velocdoubleBVRADUpper value of VRAD intervalm/sphys.velocintdVRADVRAD resolutionm/sspect.resolutiondoublesizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitsJ/A+A/640/A74/listspList of spectrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFileNameName of the spectrum file in subdirectoy spmeta.id;meta.filecharspShow the spectrummeta.ref.urlcharTitleTitle of the filemeta.title;meta.file