J/A+A/646/A18ivo://CDS.VizieR/J/A+A/646/A18doi:10.26093/cds/vizier.36460018CDSZhang C.-P.Launhardt R.Liu Y.Tobin J.J.Henning T.2022-03-23T16:32:20Z2021-02-02T07:58:58ZCDS support team

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

cds-question@unistra.frinterstellar-cloudsmillimeter-astronomysubmillimeter-astronomyPlanetary cores are thought to form in proto-planetary disks via the growth of dusty solid material. However, it is unclear how early this process begins. We study the physical structure and grain growth in the edge-on disk that surrounds the ~1Myr old low-mass (~0.55M_{sun}_) protostar embedded in the Bok Globule CB26 to examine how much grain growth has already occurred in the protostellar phase. We combine the SED between 0.9um and 6.4cm with high angular resolution continuum maps at 1.3, 2.9, and 8.1mm, and use the radiative transfer code RADMC-3D to conduct a detailed modelling of the dust emission from the disk and envelope of CB 26. We infer inner and outer disk radii of around 16au and 172+/-22au, respectively. The total gas mass in the disk is ~0.076M_{sun}_, which amounts to ~14% of the mass of the central star. The inner disk contains a compact free-free emission region, which could be related to either a jet or a photoevaporation region. The thermal dust emission from the outer disk is optically thin at mm wavelengths, while the emission from the inner disk midplane is moderately optically thick. Our best-fit radiative transfer models indicate that the dust grains in the disk have already grown to pebbles with diameters of the order of 10cm in size. Residual 8.1mm emission suggests the presence of even larger particles in the inner disk. For the optically thin mm dust emission from the outer disk, we derive a mean opacity slope of {beta}_mm_~=0.7+/-0.4, which is consistent with the presence of large dust grains. The presence of cm-sized bodies in the CB 26 disk indicates that solids grow rapidly already during the first million years in a protostellar disk. It is thus possible that Class II disks are already seeded with large particles and may contain even planetesimals.2021A&A...646A..18Zhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/646/A18CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/646/A18https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/646/A18http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/646/A18https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/646/A18https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/646/A18http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/646/A18GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/646/A18/list (List of fits images)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/646/A18/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/646/A18/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/646/A18/list?GETtext/xml+votable180.050000true74.961452.078820.0055555555555555566/1847https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/646/A18?format=asciiMillimeterdefaultJ/A+A/646/A18/table1Photometric data points for CB 26recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambdaWavelengthumem.wldoubleFluxFlux at each WavelengthmJyphot.fluxdoublee_FluxFlux at each Wavelength errormJystat.error;phot.fluxdoubleApertureAperture for each observationarcsecphys.angSize;instr.fovintInstObservational InstrumentinstrcharRef[1/4] Referece for photometric data (1)meta.ref;pos.frameintJ/A+A/646/A18/table2Beam sizes and noise levels of the millimeterHPBWPABeam size, position angledegpos.posAng;instr.beamfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintInstObservational InstrumentinstrcharlambdaObservational Wavelengthmmem.wlfloatHPBWaBeam size, major axisarcsecphys.angSizefloatHPBWbBeam size, minor axisarcsecphys.angSize;instr.beamfloatrmsObservational rmsmJy/beaminstr.det.noisefloatJ/A+A/646/A18/table3Overview of parameter ranges used in the modelingrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEnvEnvironment (1)meta.notecharParamFitted Parameter (2)stat.param;meta.modelledUnitUnit for each Fitted Parametermeta.unitRange1Range for each Parameterstat.fit.paramdoubleRange2? Range for each Parameterstat.fit.paramdoublenullableBestfitBest-fit Parameterstat.fit.paramdoubleE_Param? Upper value of Param uncertainty (3)stat.error;stat.maxdoublenullablee_Param? Lower value of Param uncertainty (3)stat.errordoublenullablen_Param[Fixed ] Fixed when uncertainty fixedmeta.notecharJ/A+A/646/A18/listList of fits imagesrecnoRecord 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.numberintObs.dateObservation datestime.epoch;obsnullablesizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitschar