The VLT/ERIS grating vector Apodizing Phase Plate coronagraph
Abstract
We describe the design, laboratory manufacture, and on-sky testing of the grating vector apodizing phase plate (gvAPP) coronagraph for the Enhanced Resolution Imager and Spectrograph (ERIS) on the Very Large Telescope. We used both laboratory measurements and on-sky observations to characterise the gvAPP in several different filters, from the K to the L band. In testing, the gvAPP reaches its design specification in the transmission of the optic with 90% in the K bands and 60% in the L band. While the gvAPP reaches its designed raw contrast performance of $1 \times 10^{-5}$, it does not reach the post-processed contrast of $5 \times 10^{-5}$ in on-sky observations. Electronic detector noise, due to the Airy core of the coronagraphic point spread function inducing cross-talk between the readout amplifiers, produces a repeated pattern within the coronagraphic regions of the gvAPP. Despite these limitations, we recommend the gvAPP as a tool for characterising substellar companions with known separations and position angles, which allow them to be placed in the coronagraphic dark holes for observations. The ERIS gvAPP's leakage term can also be used as a photometric reference for time series observations; however, we caution that the contrast performance may limit such studies to only the brightest targets. ERIS gvAPP data quality may be improved further with better modelling of detector electronic noise. This work is a pathfinder for Extremely Large Telescope instruments including METIS, which will include gvAPP coronagraphs with improved designs based on these results.
Authors 32
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Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory , Leiden University , Postbus 9513 , 2300 RA Leiden , The Netherlands
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ETH Zurich · Institute for Particle Physics and Astrophysics
Affiliation as printed
ETH Zurich , Institute for Particle Physics & Astrophysics , Wolfgang-Pauli-Str. 27 , 8093 Zurich , Switzerland
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ETH Zurich · Institute for Particle Physics and Astrophysics
Affiliation as printed
ETH Zurich , Institute for Particle Physics & Astrophysics , Wolfgang-Pauli-Str. 27 , 8093 Zurich , Switzerland
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Leiden University · Leiden Observatory · Space Research Organisation Netherlands
Affiliation as printed
Leiden Observatory , Leiden University , Postbus 9513 , 2300 RA Leiden , The Netherlands
SRON Netherlands Institute for Space Research , Niels Bohrweg 4 , 2333 CA , Leiden , The Netherlands
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Royal Observatory · University of Edinburgh
Affiliation as printed
Institute for Astronomy , University of Edinburgh , Royal Observatory , Blackford Hill , Edinburgh EH9 3HJ , UK
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Leiden University · Royal Observatory · Leiden Observatory · University of Edinburgh
Affiliation as printed
Institute for Astronomy , University of Edinburgh , Royal Observatory , Blackford Hill , Edinburgh EH9 3HJ , UK
Leiden Observatory , Leiden University , Postbus 9513 , 2300 RA Leiden , The Netherlands
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Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory , Leiden University , Postbus 9513 , 2300 RA Leiden , The Netherlands
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European Southern Observatory · Max Planck Institute for Intelligent Systems
Affiliation as printed
European Southern Observatory , Karl-Schwarzschild-Straße 2 , 85748 Garching bei München
Max Planck Institute for Intelligent Systems , Max-Planck-Ring 4 , 72076 Tübingen , Germany
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ETH Zurich · Institute for Particle Physics and Astrophysics
Affiliation as printed
ETH Zurich , Department of Earth and Planetary Sciences , Sonneggstrasse 5 , 8092 Zurich , Switzerland
ETH Zurich , Institute for Particle Physics & Astrophysics , Wolfgang-Pauli-Str. 27 , 8093 Zurich , Switzerland
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Leiden University · National Solar Observatory · Leiden Observatory
Affiliation as printed
Leiden Observatory , Leiden University , Postbus 9513 , 2300 RA Leiden , The Netherlands
National Solar Observatory , 3665 Discovery Dr. , Bounder , Co 80303 , USA
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Affiliation as printed
STAR Institute , Université de Liége , Allée du Six Août 19c , B-4000 Liége , Belgium
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Affiliation as printed
STAR Institute , Université de Liége , Allée du Six Août 19c , B-4000 Liége , Belgium
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Affiliation as printed
European Southern Observatory , Alonso de Córdova 3107 , Vitacura , Casilla 19001 , Santiago , Chile
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Ollscoil na Gaillimhe – University of Galway
Affiliation as printed
School of Natural Sciences , Center for Astronomy , University of Galway , Galway , H91 CF50 , Ireland
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Royal Observatory · University of Edinburgh
Affiliation as printed
Institute for Astronomy , University of Edinburgh , Royal Observatory , Blackford Hill , Edinburgh EH9 3HJ , UK
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University of Oxford · Universidad Diego Portales
Affiliation as printed
Instituto de Estudios Astrofísicos , Facultad de Ingeniería y Ciencias , Universidad Diego Portales , Av. Ejército Libertador 441 , Santiago , Chile
Millennium Nucleus on Young Exoplanets and their Moons (YEMS) 14 Astrophysics , University of Oxford , Denys Wilkinson Building , Keble Road , Oxford , OX1 3RH , United Kingdom
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Royal Observatory · University of Edinburgh
Affiliation as printed
Institute for Astronomy , University of Edinburgh , Royal Observatory , Blackford Hill , Edinburgh EH9 3HJ , UK
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Osservatorio Astronomico di Padova
Affiliation as printed
INAF -Osservatorio Astronomico di Padova , Vicolo dell'Osservatorio 5 , 35122 , Padova , Italy
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Affiliation as printed
Physikalisches Institut , Universität zu Köln , Zülpicher Str. 77 , 50937 , Köln , Germany
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Max Planck Institute for Extraterrestrial Physics
Affiliation as printed
Max-Planck-Institut für extraterrestrische Physik , Postfach 1312 , 85741 , Garching , Germany
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Collurania Teramo Observatory · National Institute for Astrophysics
Affiliation as printed
INAF -Osservatorio Astronomico d'Abruzzo , Via Mentore Maggini , 64100 , Teramo , Italy
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Max Planck Institute for Extraterrestrial Physics
Affiliation as printed
Max-Planck-Institut für extraterrestrische Physik , Postfach 1312 , 85741 , Garching , Germany
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ETH Zurich · Institute for Particle Physics and Astrophysics
Affiliation as printed
ETH Zurich , Institute for Particle Physics & Astrophysics , Wolfgang-Pauli-Str. 27 , 8093 Zurich , Switzerland
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Arcetri Astrophysical Observatory · National Institute for Astrophysics
Affiliation as printed
INAF -Osservatorio Astrofisico di Arcetri , largo E. Fermi 5 , 50125 Firenze , Italy
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Max Planck Institute for Extraterrestrial Physics
Affiliation as printed
Max-Planck-Institut für extraterrestrische Physik , Postfach 1312 , 85741 , Garching , Germany
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Royal Observatory · UK Astronomy Technology Centre
Affiliation as printed
STFC UK ATC , Royal Observatory Edinburgh , Blackford Hill. Edinburgh EH9 3HJ , UK
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Arcetri Astrophysical Observatory · National Institute for Astrophysics
Affiliation as printed
INAF -Osservatorio Astrofisico di Arcetri , largo E. Fermi 5 , 50125 Firenze , Italy
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Max Planck Institute for Extraterrestrial Physics
Affiliation as printed
Max-Planck-Institut für extraterrestrische Physik , Postfach 1312 , 85741 , Garching , Germany
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Arcetri Astrophysical Observatory · National Institute for Astrophysics
Affiliation as printed
INAF -Osservatorio Astrofisico di Arcetri , largo E. Fermi 5 , 50125 Firenze , Italy
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Max Planck Institute for Extraterrestrial Physics
Affiliation as printed
Max-Planck-Institut für extraterrestrische Physik , Postfach 1312 , 85741 , Garching , Germany
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Royal Observatory · UK Astronomy Technology Centre
Affiliation as printed
STFC UK ATC , Royal Observatory Edinburgh , Blackford Hill. Edinburgh EH9 3HJ , UK