J/A+A/606/A35ivo://CDS.VizieR/J/A+A/606/A35doi:10.26093/cds/vizier.36060035CDSGerin M.Pety J.Commercon B.Fuente A.Cernicharo J.Marcelino N.,Ciardi A.Lis D.C.Roueff E.Wootten H.A.Chapillon E.2017-10-09T08:04:34Z2017-10-04T08:40:15ZCDS support team

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

cds-question@unistra.frinterstellar-mediummolecular-cloudsmillimeter-astronomyphotometrysubmillimeter-astronomyThe formation epoch of protostellar disks is debated because of the competing roles of rotation, turbulence, and magnetic fields in the early stages of low-mass star formation. Magnetohydrodynamics simulations of collapsing cores predict that rotationally supported disks may form in strongly magnetized cores through ambipolar diffusion or misalignment between the rotation axis and the magnetic field orientation. Detailed studies of individual sources are needed to cross check the theoretical predictions. We present 0.06-0.1arcsec resolution images at 350GHz toward B1b-N and B1b-S, which are young class 0 protostars, possibly first hydrostatic cores. The images have been obtained with ALMA, and we compare these data with magnetohydrodynamics simulations of a collapsing turbulent and magnetized core. The submillimeter continuum emission is spatially resolved by ALMA. Compact structures with optically thick 350GHz emission are detected toward both B1b-N and B1b-S, with 0.2 and 0.35arcsec radii (46 and 80au at the Perseus distance of 230pc), within a more extended envelope. The flux ratio between the compact structure and the envelope is lower in B1b-N than in B1b-S, in agreement with its earlier evolutionary status. The size and orientation of the compact structure are consistent with 0.2arcsec resolution 32GHz observations obtained with the Very Large Array as a part of the VANDAM survey, suggesting that grains have grown through coagulation. The morphology, temperature, and densities of the compact structures are consistent with those of disks formed in numerical simulations of collapsing cores. Moreover, the properties of B1b-N are consistent with those of a very young protostar, possibly a first hydrostatic core. These observations provide support for the early formation of disks around low-mass protostars.2017A&A...606A..35Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/606/A35CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/577/L2 : Barnard 1b-N and 1b-S nascent bipolar outflows (Gerin+, 2015)J/A+A/606/L3 : Barnard 1b CO, NH_2_D and SO images (Fuente+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/606/A35https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/606/A35http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/606/A35https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/606/A35https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/606/A35http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/606/A35GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/606/A35/list (List of fits images)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/606/A35/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/606/A35/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/606/A35/list?GETtext/xml+votable180.050000true53.3383331.128830.0055555555555555566/860https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/606/A35?format=asciiRadiodefaultJ/A+A/606/A35/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 date (YYYY-MM-DDThh:mm:ss.sss)time.epoch;obscharFreqObserved frequencyGHzem.freqfloatsizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitschar