Published 2020
| Version v1
Journal article
Polarimetric imaging mode of VLT/SPHERE/IRDIS: II. Characterization and correction of instrumental polarization effects
Creators
- van Holstein, R
- Girard, J
- de Boer, J.
- Snik, F.
- Milli, J.
- Stam, D
- Ginski, C.
- Mouillet, D.
- Wahhaj, Z.
- Schmid, H
- Keller, C
- Langlois, M.
- Dohlen, K.
- Vigan, A.
- Pohl, A.
- Carbillet, M.
- Fantinel, D.
- Maurel, D.
- Origné, A.
- Petit, Cyril
- Ramos, J.
- Rigal, F.
- Sevin, A.
- Boccaletti, A.
- Le Coroller, H.
- Dominik, C.
- Henning, T.
- Lagadec, E.
- Ménard, F.
- Turatto, M.
- Udry, S.
- Chauvin, G.
- Feldt, M.
- Beuzit, Jean-Luc
Contributors
Others:
- Leiden Observatory [Leiden] ; Universiteit Leiden = Leiden University
- Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)) ; Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
- European Southern Observatory [Santiago] (ESO) ; European Southern Observatory (ESO)
- SRON Netherlands Institute for Space Research (SRON)
- Institut de Planétologie et d'Astrophysique de Grenoble (IPAG) ; Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (Fédération OSUG)-Université Grenoble Alpes (UGA)
- Institute for Particle Physics and Astrophysics [ETH Zürich] (IPA) ; Department of Physics = Departement Physik [ETH Zürich] (D-PHYS) ; Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)
- Centre de Recherche Astrophysique de Lyon (CRAL) ; École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
- Laboratoire d'Astrophysique de Marseille (LAM) ; Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
- Max-Planck-Institut für Astronomie (MPIA) ; Max-Planck-Gesellschaft
- Joseph Louis LAGRANGE (LAGRANGE) ; Université Nice Sophia Antipolis (1965 - 2019) (UNS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur ; Université Côte d'Azur (UniCA)-Université Côte d'Azur (UniCA)-Centre National de la Recherche Scientifique (CNRS)
- INAF - Osservatorio Astronomico di Padova (OAPD) ; Istituto Nazionale di Astrofisica (INAF)
- DOTA, ONERA, Université Paris Saclay [Palaiseau] ; ONERA-Université Paris-Saclay
- Astronomical Institute Anton Pannekoek (AI PANNEKOEK) ; University of Amsterdam [Amsterdam] = Universiteit van Amsterdam (UvA)
- Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA) ; Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
- Observatoire Astronomique de l'Université de Genève (ObsGE) ; Université de Genève = University of Geneva (UNIGE)
- European Southern Observatory (ESO)
Description
Context: Circumstellar disks and self-luminous giant exoplanets or companion brown dwarfs can be characterized through direct-imaging polarimetry at near-infrared wavelengths. SPHERE/IRDIS at the Very Large Telescope has the capabilities to perform such measurements, but uncalibrated instrumental polarization effects limit the attainable polarimetric accuracy.Aims: We aim to characterize and correct the instrumental polarization effects of the complete optical system, that is, the telescope and SPHERE/IRDIS.Methods: We created a detailed Mueller matrix model in the broadband filters Y, J, H, and K s and calibrated the model using measurements with SPHERE's internal light source and observations of two unpolarized stars. We developed a data-reduction method that uses the model to correct for the instrumental polarization effects, and applied it to observations of the circumstellar disk of T Cha. Results. The instrumental polarization is almost exclusively produced by the telescope and SPHERE's first mirror and varies with telescope altitude angle. The crosstalk primarily originates from the image derotator (K-mirror). At some orientations, the derotator causes severe loss of signal (> 90% loss in the H - and K s -band) and strongly offsets the angle of linear polarization. With our correction method we reach, in all filters, a total polarimetric accuracy of ≲0.1% in the degree of linear polarization and an accuracy of a few degrees in angle of linear polarization. Conclusions: The correction method enables us to accurately measure the polarized intensity and angle of linear polarization of circumstellar disks, and is a vital tool for detecting spatially unresolved (inner) disks and measuring the polarization of substellar companions. We have incorporated the correction method in a highly-automated end-to-end data-reduction pipeline called IRDAP, which we made publicly available online.
Abstract
International audienceAdditional details
Identifiers
- URL
- https://hal.science/hal-04712657
- URN
- urn:oai:HAL:hal-04712657v1
Origin repository
- Origin repository
- UNICA