Show simple item record

Authordc.contributor.authorPohl, A. 
Authordc.contributor.authorSissa, E. 
Authordc.contributor.authorLanglois, M. 
Authordc.contributor.authorZurlo, A. 
Admission datedc.date.accessioned2018-07-05T15:04:10Z
Available datedc.date.available2018-07-05T15:04:10Z
Publication datedc.date.issued2017
Cita de ítemdc.identifier.citationAstronomy & Astrophysics, 605, A34 (2017)es_ES
Identifierdc.identifier.other10.1051/0004-6361/201630234
Identifierdc.identifier.urihttps://repositorio.uchile.cl/handle/2250/149540
Abstractdc.description.abstractContext. The transition disk around the T Tauri star T Cha possesses a large gap, making it a prime target for high-resolution imaging in the context of planet formation. Aims. We aim to find signs of disk evolutionary processes by studying the disk geometry and the dust grain properties at its surface, and to search for companion candidates. Methods. We analyze a set of VLT/SPHERE data at near-infrared and optical wavelengths. We performed polarimetric imaging of T Cha with IRDIS (1.6 mu m) and ZIMPOL (0.5-0.9 mu m), and obtained intensity images from IRDIS dual-band imaging with simultaneous spectro-imaging with IFS (0.9-1.3 mu m). Results. The disk around T Cha is detected in all observing modes and its outer disk is resolved in scattered light with unprecedented angular resolution and signal-to-noise. The images reveal a highly inclined disk with a noticeable east-west brightness asymmetry. The significant amount of non-azimuthal polarization signal in the U-phi images, with a U-phi/Q(phi) peak-to-peak value of 14%, is in accordance with theoretical studies on multiple scattering in an inclined disk. Our optimal axisymmetric radiative transfer model considers two coplanar inner and outer disks, separated by a gap of 0.'' 28 (similar to 30 au) in size, which is larger than previously thought. We derive a disk inclination of similar to 69 deg and PA of similar to 114 deg. In order to self-consistently reproduce the intensity and polarimetric images, the dust grains, responsible for the scattered light, need to be dominated by sizes of around ten microns. A point source is detected at an angular distance of 3.5 '' from the central star. It is, however, found not to be co-moving. Conclusions. We confirm that the dominant source of emission is forward scattered light from the near edge of the outer disk. Our point source analysis rules out the presence of a companion with mass larger than similar to 8.5 M-jup between 0.'' 1 and 0.'' 3. The detection limit decreases to similar to 2 M-jup for 0.'' 3 to 4.0 ''.es_ES
Patrocinadordc.description.sponsorship"Progetti Premiali" funding scheme of the Italian Ministry of Education, University, and Research ANR of France ANR-16-CE31-0013 ALMA/Conicyt 31130027 Millennium Nucleus (Chilean Ministry of Economy) RC130007 ESO European Commission Sixth and Seventh Framework Programmes as part of the Optical Infrared Coordination Network for Astronomy (OPTICON) RII3-Ct-2004-001566 226604 312430 CNRS (France) MPIA (Germany) INAF (Italy) FINES (Switzerland) NOVA (Netherlands)es_ES
Lenguagedc.language.isoenes_ES
Publisherdc.publisherEDP Scienceses_ES
Sourcedc.sourceAstronomy & Astrophysicses_ES
Keywordsdc.subjectStars individual: T Chaes_ES
Keywordsdc.subjectProtoplanetary diskses_ES
Keywordsdc.subjectTechniques polarimetrices_ES
Keywordsdc.subjectRadiative transferes_ES
Keywordsdc.subjectScatteringes_ES
Keywordsdc.subjectCircumstellar matteres_ES
Títulodc.titleNew constraints on the disk characteristics and companion candidates around T Chamaeleontis with VLT/SPHEREes_ES
Document typedc.typeArtículo de revistaes_ES
dcterms.accessRightsdcterms.accessRightsAcceso a solo metadatoses_ES
Catalogueruchile.catalogadortjnes_ES
Indexationuchile.indexArtículo de publicación ISIes_ES


Files in this item

Icon

This item appears in the following Collection(s)

Show simple item record