Euclid : Searches for strong gravitational lenses using convolutional neural nets in Early Release Observations of the Perseus field
Astronomy and Astrophysics, vol. 696, pp. A214
Abstract
The Euclid Wide Survey (EWS) is predicted to find approximately 170 000 galaxy-galaxy strong lenses from its lifetime observation of 14 000 deg 2 of the sky. Detecting this many lenses by visual inspection with professional astronomers and citizen scientists alone is infeasible. As a result, machine learning algorithms, particularly convolutional neural networks (CNNs), have been used as an automated method of detecting strong lenses, and have proven fruitful in finding galaxy-galaxy strong lens candidates, such that the usage of CNNs in lens identification has increased. We identify the major challenge to be the automatic detection of galaxy-galaxy strong lenses while simultaneously maintaining a low false positive rate, thus producing a pure and complete sample of strong lens candidates from Euclid with a limited need for visual inspection. One aim of this research is to have a quantified starting point on the achieved purity and completeness with our current version of CNN-based detection pipelines for the VIS images of EWS. This work is vital in preparing our CNN-based detection pipelines to be able to produce a pure sample of the >100 000 strong gravitational lensing systems widely predicted for Euclid . We select all sources with VIS I E < 23 mag from the Euclid Early Release Observation imaging of the Perseus field. We apply a range of CNN architectures to detect strong lenses in these cutouts. All our networks perform extremely well on simulated data sets and their respective validation sets. However, when applied to real Euclid imaging, the highest lens purity is just ∼11%. Among all our networks, the false positives are typically identifiable by human volunteers as, for example, spiral galaxies, multiple sources, and artifacts, implying that improvements are still possible, perhaps via a second, more interpretable lens selection filtering stage. There is currently no alternative to human classification of CNN-selected lens candidates. Given the expected ∼10 5 lensing systems in Euclid , this implies 10 6 objects for human classification, which while very large is not in principle intractable and not without precedent.
Authors 63
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Affiliation as printed
School of Physical Sciences, The Open University, Milton Keynes MK7 6AA, UK
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Affiliation as printed
Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands
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Astronomical Observatory of Capodimonte · Istituto Nazionale di Fisica Nucleare, Sezione di Napoli · University of Naples Federico II · National Institute for Astrophysics
Affiliation as printed
Department of Physics “E. Pancini”, University Federico II, Via Cinthia 6, 80126 Napoli, Italy
INAF – Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy
INFN section of Naples, Via Cinthia 6, 80126 Napoli, Italy
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University of Trento · Arcetri Astrophysical Observatory · University of Florence
Affiliation as printed
Dipartimento di Fisica e Astronomia, Università di Firenze, via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
University of Trento, Via Sommarive 14, 38123 Trento, Italy
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Max Planck Institute for Astrophysics · Technical University of Munich
Affiliation as printed
Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching, Germany
Technical University of Munich, TUM School of Natural Sciences, Physics Department, James-Franck-Str. 1, 85748 Garching, Germany
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics · University of Bologna
Affiliation as printed
Dipartimento di Fisica e Astronomia “Augusto Righi” – Alma Mater Studiorum Università di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy
INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy
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FHNW University of Applied Sciences and Arts Northwestern Switzerland
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University of Applied Sciences and Arts of Northwestern Switzerland, School of Engineering, 5210 Windisch, Switzerland
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Affiliation as printed
School of Physical Sciences, The Open University, Milton Keynes MK7 6AA, UK
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University of Toronto · University of Manchester
Affiliation as printed
David A. Dunlap Department of Astronomy & Astrophysics, University of Toronto, 50 St George Street, Toronto, Ontario M5S 3H4, Canada
Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
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École Polytechnique Fédérale de Lausanne
Affiliation as printed
Institute of Physics, Laboratory of Astrophysics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny, 1290 Versoix, Switzerland
SCITAS, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
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Institució Catalana de Recerca i Estudis Avançats · Institut de Ciències del Cosmos · Universitat de Barcelona
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Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig de Lluís Companys 23, 08010 Barcelona, Spain
Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona (IEEC-UB), Martí i Franquès 1, 08028 Barcelona, Spain
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Centre National de la Recherche Scientifique · Aix-Marseille Université · Institut d'Astrophysique de Paris · Sorbonne Université
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Aix-Marseille Université, CNRS, CNES, LAM, Marseille, France
Institut d’Astrophysique de Paris, UMR 7095, CNRS, and Sorbonne Université, 98 bis boulevard Arago, 75014 Paris, France
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics · University of Bologna
Affiliation as printed
Dipartimento di Fisica e Astronomia “Augusto Righi” – Alma Mater Studiorum Università di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy
INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy
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Centre National de la Recherche Scientifique · Université Toulouse III - Paul Sabatier · Institut de Recherche en Astrophysique et Planétologie · Université de Toulouse
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Institut de Recherche en Astrophysique et Planétologie (IRAP), Université de Toulouse, CNRS, UPS, CNES, 14 Av. Edouard Belin, 31400 Toulouse, France
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Lyon 1 Université · Centre National de la Recherche Scientifique · Institut National de Physique Nucléaire et de Physique des Particules · Institut de Physique des 2 Infinis de Lyon
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UCB Lyon 1, CNRS/IN2P3, IUF, IP2I Lyon, 4 rue Enrico Fermi, 69622 Villeurbanne, France
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Max Planck Institute for Astronomy
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Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
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University of Liège · Durham University
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Department of Physics, Centre for Extragalactic Astronomy, Durham University, South Road, Durham, DH1 3LE, UK
Department of Physics, Institute for Computational Cosmology, Durham University, South Road, Durham DH1 3LE, UK
STAR Institute, Quartier Agora – Allée du six Août, 19c 4000 Liège, Belgium
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Istituto Nazionale di Fisica Nucleare, Sezione di Bologna · Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics
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INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy
INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy
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École Polytechnique Fédérale de Lausanne
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Institute of Physics, Laboratory of Astrophysics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny, 1290 Versoix, Switzerland
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University of Salento · Istituto Nazionale di Fisica Nucleare, Sezione di Lecce · National Institute for Astrophysics
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Department of Mathematics and Physics E. De Giorgi, University of Salento, Via per Arnesano, CP-I93, 73100 Lecce, Italy
INAF-Sezione di Lecce, c/o Dipartimento Matematica e Fisica, Via per Arnesano, 73100, Lecce, Italy
INFN, Sezione di Lecce, Via per Arnesano, CP-193, 73100 Lecce, Italy
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Minnesota Institute for Astrophysics, University of Minnesota, 116 Church St SE, Minneapolis, MN 55455, USA
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Affiliation as printed
STAR Institute, Quartier Agora – Allée du six Août, 19c 4000 Liège, Belgium
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Max Planck Institute for Astrophysics · Technical University of Munich
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Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching, Germany
Technical University of Munich, TUM School of Natural Sciences, Physics Department, James-Franck-Str. 1, 85748 Garching, Germany
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Max Planck Institute for Astrophysics
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Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching, Germany
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics
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INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy
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Centre National de la Recherche Scientifique · Observatoire astronomique de Strasbourg · Université de Strasbourg
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Université de Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, 67000 Strasbourg, France
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Max Planck Institute for Astronomy
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Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
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Department of Physics, Université de Montréal, 2900 Edouard Montpetit Blvd, Montréal, Québec H3T 1J4, Canada
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Centre National de la Recherche Scientifique · Université de Montpellier · Laboratoire Univers et Particules de Montpellier
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Laboratoire univers et particules de Montpellier, Université de Montpellier, CNRS, 34090 Montpellier, France
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Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands
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Arcetri Astrophysical Observatory
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INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
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Universidad Politécnica de Cartagena
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Departamento Física Aplicada, Universidad Politécnica de Cartagena, Campus Muralla del Mar, 30202 Cartagena, Murcia, Spain
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School of Physical Sciences, The Open University, Milton Keynes MK7 6AA, UK
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Max Planck Institute for Astrophysics
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Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching, Germany
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Centre National de la Recherche Scientifique · Université de Bordeaux · Laboratoire d'Astrophysique de Bordeaux
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Laboratoire d’Astrophysique de Bordeaux, CNRS and Université de Bordeaux, Allée Geoffroy St. Hilaire, 33165 Pessac, France
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European Space Astronomy Centre
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ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Cañada, Madrid, Spain
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School of Mathematics and Physics, University of Surrey, Guildford, Surrey, GU2 7XH, UK
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Brera Astronomical Observatory
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INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy
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Scuola Internazionale Superiore di Studi Avanzati · Trieste Astronomical Observatory · Istituto Nazionale di Fisica Nucleare, Sezione di Trieste · Institute for Fundamental Physics of the Universe
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IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy
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INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy
SISSA, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste TS, Italy
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics
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INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy
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Astronomical Observatory of Capodimonte · Istituto Nazionale di Fisica Nucleare, Sezione di Napoli · University of Naples Federico II · National Institute for Astrophysics
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Department of Physics “E. Pancini”, University Federico II, Via Cinthia 6, 80126 Napoli, Italy
INAF – Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy
INFN section of Naples, Via Cinthia 6, 80126 Napoli, Italy
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Centre National de la Recherche Scientifique · Aix-Marseille Université
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Aix-Marseille Université, CNRS, CNES, LAM, Marseille, France
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Istituto Nazionale di Fisica Nucleare, Sezione di Torino · Osservatorio Astrofisico di Torino · University of Turin
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Dipartimento di Fisica, Università degli Studi di Torino, Via P. Giuria 1, 10125 Torino, Italy
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INFN-Sezione di Torino, Via P. Giuria 1, 10125 Torino, Italy
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Osservatorio Astrofisico di Torino
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INAF – Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese (TO), Italy
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National Institute for Astrophysics
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Port d'Informació Científica · Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas
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Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Avenida Complutense 40, 28040 Madrid, Spain
Port d’Informació Científica, Campus UAB, C. Albareda s/n, 08193 Bellaterra (Barcelona), Spain
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University of Portsmouth · RWTH Aachen University
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Institute for Theoretical Particle Physics and Cosmology (TTK), RWTH Aachen University, 52056 Aachen, Germany
Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX, UK
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Astronomical Observatory of Rome · National Institute for Astrophysics
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INAF – Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics
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INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy
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Dipartimento di Fisica e Astronomia “Augusto Righi” – Alma Mater Studiorum Università di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy
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Instituto de Astrofísica de Canarias
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Instituto de Astrofísica de Canarias, Calle Vía Láctea s/n, 38204, San Cristóbal de La Laguna, Tenerife, Spain
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Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
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European Space Agency · European Space Astronomy Centre · European Space Research Institute
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ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Cañada, Madrid, Spain
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Lyon 1 Université · Centre National de la Recherche Scientifique · Institut National de Physique Nucléaire et de Physique des Particules · Institut de Physique des 2 Infinis de Lyon
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Université Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, Villeurbanne 69100, France
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Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK
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Department of Astronomy, University of Geneva, ch. d’Ecogia 16, 1290 Versoix, Switzerland
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Trieste Astronomical Observatory
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INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy
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Affiliation as printed
Department of Astronomy, University of Geneva, ch. d’Ecogia 16, 1290 Versoix, Switzerland
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European Space Astronomy Centre
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ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Cañada, Madrid, Spain
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Istituto Nazionale di Fisica Nucleare, Sezione di Padova
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INFN-Padova, Via Marzolo 8, 35131 Padova, Italy
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Institute for Space Astrophysics and Planetology · National Institute for Astrophysics
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INAF-Istituto di Astrofisica e Planetologia Spaziali, via del Fosso del Cavaliere, 100, 00100 Roma, Italy
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Centre National de la Recherche Scientifique · Université Paris Cité · Commissariat à l'Énergie Atomique et aux Énergies Alternatives · Université Paris-Saclay · Astrophysique, Instrumentation et Modélisation
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Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM, 91191, Gif-sur-Yvette, France
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Astronomical Observatory of Rome · Agenzia Spaziale Italiana · National Institute for Astrophysics
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INAF – Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy
Space Science Data Center, Italian Space Agency, via del Politecnico snc, 00133 Roma, Italy
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