J/A+A/648/A110ivo://CDS.VizieR/J/A+A/648/A110doi:10.26093/cds/vizier.36480110CDSHunziker S.Schmid H.M.Ma J.Menard F.Avenhaus H.Boccaletti A.,Beuzit J.L.Chauvin G.Dohlen K.Dominik C.Engler N.Ginski C.,Gratton R.Henning T.Langlois M.Milli J.Mouillet D.Tschudi C.,van Holstein R.G.Vigan A.2021-09-16T10:42:59Z2021-04-21T07:34:36ZCDS support team

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

cds-question@unistra.fremission-line-starspolarimetryWe present high-precision photometry and polarimetry based on visual and near-infrared imaging data for the protoplanetary disk surrounding the Herbig Ae/Be star HD 142527, with a strong focus on determining the light scattering parameters of the dust located at the surface of the large outer disk. We re-reduced existing polarimetric differential imaging data of HD 142527 in the VBB (735nm) and H-band (1625nm) from the ZIMPOL and IRDIS subinstruments of SPHERE at the VLT. With polarimetry and photometry based on reference star differential imaging (RDI), we were able to measure the linearly polarized intensity and the total intensity of the light scattered by the circumstellar disk with high precision. We used simple Monte Carlo simulations of multiple light scattering by the disk surface to derive constraints for three scattering parameters of the dust: the maximum polarization of the scattered light Pmax, the asymmetry parameter g, and the single-scattering albedo {omega}. We measure a reflected total intensity of 51.4+/-1.5mJy and 206+/-12mJy and a polarized intensity of 11.3+/-0.3mJy and 55.1+/-3.3mJy in the VBB and H-band, respectively. We also find in the visual range a degree of polarization that varies between 28% on the far side of the disk and 17% on the near side. In the H-band, the degree of polarization is consistently higher by about a factor of 1.2. The disk also shows a red color for the scattered light intensity and the polarized intensity, which are about twice as high in the near-infrared when compared to the visual. We determine with model calculations the scattering properties of the dust particles and find evidence for strong forward scattering (g {prop.to} 0.5-0.75), relatively low single-scattering albedo ({omega} {prop.to} 0.2-0.5), and high maximum polarization (Pmax {prop.to} 0.5-0.75) at the surface on the far side of the disk for both observed wavelengths. The optical parameters indicate the presence of large aggregate dust particles, which are necessary to explain the high maximum polarization, the strong forward-scattering nature of the dust, and the observed red disk color.2021A&A...648A.110Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/648/A110CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/648/A110https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/648/A110http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/648/A110https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/648/A110https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/648/A110http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/648/A110GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/648/A110/list (List of fits images)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/648/A110/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/648/A110/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/648/A110/list?GETtext/xml+votable180.050000true239.17426-42.322830.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/648/A1106/42595https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/648/A110?format=asciidefaultJ/A+A/648/A110/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.numberintsizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitscharAssocDataAssociated Data web pagemeta.ref.urlchar