J/ApJ/860/82ivo://CDS.VizieR/J/ApJ/860/82doi:10.26093/cds/vizier.18600082CDSHull C.L.H.Yang H.Li Z.-Y.Kataoka A.Stephens I.W.Andrews S.,Bai X.Cleeves L.I.Hughes A.M.Looney L.Perez L.M.Wilner D.2019-08-21T10:20:45Z2019-07-31T11:22:52ZCDS support team

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

cds-question@unistra.frpolarimetryyoung-stellar-objectsmillimeter-astronomysubmillimeter-astronomyWe present 870{mu}m ALMA observations of polarized dust emission toward the Class II protoplanetary disk IM Lup. We find that the orientation of the polarized emission is along the minor axis of the disk, and that the value of the polarization fraction increases steadily toward the center of the disk, reaching a peak value of ~1.1%. All of these characteristics are consistent with models of self-scattering of submillimeter-wave emission from an optically thin inclined disk. The distribution of the polarization position angles across the disk reveals that, while the average orientation is along the minor axis, the polarization orientations show a significant spread in angles; this can also be explained by models of pure scattering. We compare the polarization with that of the Class I/II source HL Tau. A comparison of cuts of the polarization fraction across the major and minor axes of both sources reveals that IM Lup has a substantially higher polarization fraction than HL Tau toward the center of the disk. This enhanced polarization fraction could be due a number of factors, including higher optical depth in HL Tau, or scattering by larger dust grains in the more evolved IM Lup disk. However, models yield similar maximum grain sizes for both HL Tau (72{mu}m) and IM Lup (61{mu}m, this work). This reveals continued tension between grain-size estimates from scattering models and from models of the dust emission spectrum, which find that the bulk of the (unpolarized) emission in disks is most likely due to millimeter-sized (or even centimeter-sized) grains.2018ApJ...860...82Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/860/82CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/213/13 : 1.3mm polarization maps of star-forming cores (Hull+, 2014)J/A+A/592/A49 : TW Hya CO (2-1), CN (2-1) & CS (5-4) data cubes (Teague+, 2016)J/A+A/600/A20 : Lupus YSOs X-shooter spectroscopy (Alcala+, 2017)J/ApJ/847/92 : Polarization data toward Serpens SMM1 (Hull+, 2017)J/ApJ/842/L9 : ALMA obs. of Ser-emb 8 polarized dust emission (Hull+, 2017)J/ApJ/845/44 : 340GHz SMA obs. of 50 protoplanetary disks (Tripathi+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/860/82https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/860/82http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/860/82https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/860/82https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/860/82http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/860/82GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/860/82/table1 (ALMA polarization data)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/860/82/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/860/82/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/860/82/table1?GETtext/xml+votable180.050000true239.03854-37.935390.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/ApJ/860/826/42704https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/860/82?format=asciiMillimeterdefaultJ/ApJ/860/82/table1ALMA polarization datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000[239.038/239.039] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-37.94/-37.93] Declination (J2000)degpos.eq.dec;meta.mainI[11.7/118.8] Stokes I total intensitymJy/beamphys.polarization.stokesfloatPol[0.06/1.4] Polarized intensitymJy/beamphot.flux.densityfloatchi[23.8/66.4] Polarization position angledegpos.posAng;phys.polarizationfloate_chi[0.4/7.7] Uncertainty in chidegstat.errorfloatPfrac[0.003/0.02] Fractional polarizationphys.polarization.linearfloate_Pfrac[0.0002/0.002] Uncertainty in Pfracstat.errorfloat