Girart, J. M.J. M.GirartFernández-López, M.M.Fernández-LópezLi, Z. -Y.Z. -Y.LiYang, H.H.YangEstalella, R.R.EstalellaAnglada, G.G.AngladaÁñez-López, N.N.Áñez-LópezBusquet, G.G.BusquetCarrasco-González, C.C.Carrasco-GonzálezCuriel, S.S.CurielGalvan-Madrid, R.R.Galvan-MadridGómez, J. F.J. F.Gómezde Gregorio-Monsalvo, I.I.de Gregorio-MonsalvoJiménez-Serra, I.I.Jiménez-SerraKrasnopolsky, R.R.KrasnopolskyMartí, J.J.MartíOsorio, M.M.OsorioPadovani, MarcoMarcoPadovaniRao, R.R.RaoRodríguez, L. F.L. F.RodríguezTorrelles, J. M.J. M.Torrelles2020-10-122020-10-1220180004-637Xhttp://hdl.handle.net/20.500.12386/27732Here we present deep (16 μJy beam<SUP>-1</SUP>), very high (40 mas) angular resolution 1.14 mm, polarimetric, Atacama Large Millimeter/submillimeter Array (ALMA) observations toward the massive protostar driving the HH 80-81 radio jet. The observations clearly resolve the disk oriented perpendicularly to the radio jet, with a radius of ≃0.″171 (∼291 au at 1.7 kpc distance). The continuum brightness temperature, the intensity profile, and the polarization properties clearly indicate that the disk is optically thick for a radius of R ≲ 170 au. The linear polarization of the dust emission is detected almost all along the disk, and its properties suggest that dust polarization is produced mainly by self-scattering. However, the polarization pattern presents a clear differentiation between the inner (optically thick) part of the disk and the outer (optically thin) region of the disk, with a sharp transition that occurs at a radius of ∼0.″1 (∼170 au). The polarization characteristics of the inner disk suggest that dust settling has not occurred yet with a maximum dust grain size between 50 and 500 μm. The outer part of the disk has a clear azimuthal pattern but with a significantly higher polarization fraction compared to the inner disk. This pattern is broadly consistent with the self-scattering of a radiation field that is beamed radially outward, as expected in the optically thin outer region, although contribution from non-spherical grains aligned with respect to the radiative flux cannot be excluded.STAMPAenArticle10.3847/2041-8213/aab76b2-s2.0-85045538510000428772600001https://iopscience.iop.org/article/10.3847/2041-8213/aab76b2018ApJ...856L..27GFIS/05 - ASTRONOMIA E ASTROFISICA