Euclid Quick Data Release (Q1)
Astronomy and Astrophysics, vol. 711, pp. A285
Abstract
The slitless spectroscopy mode of the Near-Infrared Spectrometer and Photometer (NISP) on board the Euclid telescope has enabled efficient spectroscopy of objects within a large field of view. Nevertheless, the relatively low spectral resolution, overlapping spectra, and contamination pose challenges to source classification and redshift determination using the NISP spectra alone. In this work, we present a large and homogeneous sample of bright quasars identified from the Euclid Quick Data Release (Q1), constructed by combining high-purity candidate selections from Gaia and WISE with the new spectroscopic capabilities of Euclid . Through visual inspection of the Euclid spectra of these quasar candidates, we identify approximately 3500 quasars and determine reliable redshifts in the range of 0 < z ≲ 4.8. Of these, 2686 are new spectroscopic identifications relative to existing public compilations. We generated the first Euclid composite spectrum of quasars covering rest-frame near-ultraviolet (NUV) to near-infrared (NIR) wavelengths without telluric lines, which will be pivotal to NIR quasar spectral analysis. We obtained an empirical spectroscopic depth of J E ≲ 21.5 and H E ≲ 21.3 at the sensitivity of the Wide Field Survey, beyond which the number of securely identified quasars declines sharply. Accordingly, the sample presented in this paper comprises spectroscopically confirmed quasars brighter than these limits. We analysed morphological parameters from the Visible Camera (VIS) using Sérsic and model-independent (CAS) metrics, and a deep-learning point spread function fraction ( f PSF ) to track nuclear dominance. The VIS morphologies show a clear redshift dependence: at low redshift ( z < 0.5), obvious host structures are common and a single Sérsic model fits about half of the sources; at intermediate redshift (0.5 < z < 2), the nuclear component dominates, with 90% of the Sérsic fits saturating at the upper index limit. In this intermediate redshift regime, f PSF is available, and we use it as a more reliable compactness measure than the single-Sérsic and CAS parameters to quantify nuclear versus host emission. We also explore the novel Euclid NIR colour space and discuss the role of these quasars in refining active galactic nucleus selection techniques for future Euclid data releases.
Authors 97
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Leiden University · University of Groningen · Leiden Observatory
Affiliation as printed
Kapteyn Astronomical Institute, University of Groningen
Leiden Observatory, Leiden University
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Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University
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Affiliation as printed
Cosmic Dawn Center (DAWN)
Kapteyn Astronomical Institute, University of Groningen
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics
Affiliation as printed
INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
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National Institute for Astrophysics · University of Trento · University of Florence · Arcetri Astrophysical Observatory
Affiliation as printed
Dipartimento di Fisica e Astronomia, Università di Firenze
INAF-Osservatorio Astrofisico di Arcetri
University of Trento
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Space Research Organisation Netherlands
Affiliation as printed
SRON Netherlands Institute for Space Research
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University of Groningen · Space Research Organisation Netherlands
Affiliation as printed
Kapteyn Astronomical Institute, University of Groningen
SRON Netherlands Institute for Space Research
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics
Affiliation as printed
INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
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Affiliation as printed
School of Physics & Astronomy, University of Southampton
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Max Planck Institute for Astronomy
Affiliation as printed
Max-Planck-Institut für Astronomie
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National Institute for Astrophysics · Arcetri Astrophysical Observatory
Affiliation as printed
INAF-Osservatorio Astrofisico di Arcetri
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Academia Sinica · Institute of Astronomy and Astrophysics, Academia Sinica · Ritsumeikan University
Affiliation as printed
Academia Sinica Institute of Astronomy and Astrophysics (ASIAA)
Department of Physical Sciences, Ritsumeikan University
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National Institute for Astrophysics · Astronomical Observatory of Capodimonte
Affiliation as printed
INAF-Osservatorio Astronomico di Capodimonte
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University of Geneva · ETH Zurich · Institute for Particle Physics and Astrophysics
Affiliation as printed
Department of Astronomy, University of Geneva
Institute for Particle Physics and Astrophysics, Dept. of Physics, ETH Zurich
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University of Bologna · Universidade do Porto · Institute of Astrophysics and Space Sciences · Centro de Astrofísica da Universidade do Porto
Affiliation as printed
Dipartimento di Fisica e Astronomia, Università di Bologna
Faculdade de Ciências da Universidade do Porto
Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP
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Universidade do Porto · Institute of Astrophysics and Space Sciences · Centro de Astrofísica da Universidade do Porto · DTX Digital Transformation CoLAB
Affiliation as printed
DTx – Digital Transformation CoLAB
Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP
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National Institute for Astrophysics
Affiliation as printed
INAF-IASF Milano
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National Institute for Astrophysics · Arcetri Astrophysical Observatory
Affiliation as printed
INAF-Osservatorio Astrofisico di Arcetri
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National Institute for Astrophysics
Affiliation as printed
INAF-IASF Milano
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National Institute for Astrophysics · Roma Tre University · Astronomical Observatory of Rome
Affiliation as printed
Department of Mathematics and Physics, Roma Tre University
INAF-Osservatorio Astronomico di Roma
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Affiliation as printed
Department of Physics, Centre for Extragalactic Astronomy, Durham University
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National Institute for Astrophysics · Institute for Space Astrophysics and Planetology
Affiliation as printed
INAF-Istituto di Astrofisica e Planetologia Spaziali
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Affiliation as printed
School of Physics, HH Wills Physics Laboratory, University of Bristol
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Affiliation as printed
Jet Propulsion Laboratory, California Institute of Technology
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Affiliation as printed
Department of Physics, Centre for Extragalactic Astronomy, Durham University
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics
Affiliation as printed
INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
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Max Planck Institute for Extraterrestrial Physics
Affiliation as printed
Max Planck Institute for Extraterrestrial Physics
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Institut de Physique des 2 Infinis de Lyon · Max Planck Institute for Extraterrestrial Physics
Affiliation as printed
Max Planck Institute for Extraterrestrial Physics
IP2I Lyon - Institut de Physique des 2 Infinis de Lyon (Campus LyonTech-la Doua Bâtiment Paul DIRAC 4 Rue Enrico Fermi 69622 Villeurbanne Cedex - France)
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Centre National de la Recherche Scientifique · Institut d'Astrophysique Spatiale · Institut National de Physique Nucléaire et de Physique des Particules · Université de Lille · Lyon 1 Université · Institut de Physique des 2 Infinis de Lyon · Centre de Recherche en Informatique, Signal et Automatique de Lille
Affiliation as printed
Université Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822
CRIStAL - Centre de Recherche en Informatique, Signal et Automatique de Lille - UMR 9189 (Université de Lille - Campus scientifique - Bâtiment ESPRIT - Avenue Henri Poincaré - 59655 Villeneuve d’Ascq - France)
IAS - Institut d'astrophysique spatiale (Bâtiment 121 91405 ORSAY CEDEX - France)
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Centre National de la Recherche Scientifique · Université Paris-Saclay · Institut d'Astrophysique Spatiale · Université de Lille · Centrale Lille Institut · Centre de Recherche en Informatique, Signal et Automatique de Lille
Affiliation as printed
Univ. Lille, CNRS, Centrale Lille, UMR 9189 CRIStAL
Université Paris-Saclay, CNRS, Institut d’astrophysique spatiale
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University of British Columbia
Affiliation as printed
Department of Physics and Astronomy, University of British Columbia
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Leiden University · University of Edinburgh · Royal Observatory · Leiden Observatory
Affiliation as printed
Institute for Astronomy, University of Edinburgh, Royal Observatory
Leiden Observatory, Leiden University
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National Institute for Astrophysics · University of Florence · Arcetri Astrophysical Observatory
Affiliation as printed
Dipartimento di Fisica e Astronomia, Università di Firenze
INAF-Osservatorio Astrofisico di Arcetri
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Max Planck Institute for Astronomy
Affiliation as printed
Max-Planck-Institut für Astronomie
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Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University
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Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University
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National Institute for Astrophysics · Max Planck Institute for Extraterrestrial Physics · Astronomical Observatory of Capodimonte
Affiliation as printed
INAF-Osservatorio Astronomico di Capodimonte
Max Planck Institute for Extraterrestrial Physics
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Universidad de La Laguna · Instituto de Astrofísica de Canarias · Institute of Space Sciences
Affiliation as printed
Institute of Space Sciences (ICE, CSIC), Campus UAB
Instituto de Astrofísica de Canarias, E-38205 La Laguna; Universidad de La Laguna
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics · Max Planck Institute for Astronomy
Affiliation as printed
INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
Max-Planck-Institut für Astronomie
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National Institute for Astrophysics · Astronomical Observatory of Capodimonte
Affiliation as printed
INAF-Osservatorio Astronomico di Capodimonte
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Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory, Leiden University
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National Institute for Astrophysics · Brera Astronomical Observatory
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INAF-Osservatorio Astronomico di Brera
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics
Affiliation as printed
INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
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Scuola Internazionale Superiore di Studi Avanzati · National Institute for Astrophysics · 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
INAF-Osservatorio Astronomico di Trieste
INFN, Sezione di Trieste
SISSA, International School for Advanced Studies
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics · Istituto Nazionale di Fisica Nucleare, Sezione di Bologna · University of Bologna
Affiliation as printed
Dipartimento di Fisica e Astronomia, Università di Bologna
INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
INFN-Sezione di Bologna
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National Institute for Astrophysics · Osservatorio Astronomico di Padova
Affiliation as printed
INAF-Osservatorio Astronomico di Padova
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics
Affiliation as printed
INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics
Affiliation as printed
INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
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National Institute for Astrophysics · Trieste Astronomical Observatory · Institute for Fundamental Physics of the Universe
Affiliation as printed
IFPU, Institute for Fundamental Physics of the Universe
INAF-Osservatorio Astronomico di Trieste
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National Institute for Astrophysics · University of Genoa · Istituto Nazionale di Fisica Nucleare, Sezione di Genova · Brera Astronomical Observatory
Affiliation as printed
Dipartimento di Fisica, Università di Genova
INAF-Osservatorio Astronomico di Brera
INFN-Sezione di Genova
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National Institute for Astrophysics · University of Naples Federico II · Astronomical Observatory of Capodimonte
Affiliation as printed
Department of Physics “E. Pancini”, University Federico II
INAF-Osservatorio Astronomico di Capodimonte
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European Space Agency · Universidade do Porto · Institute of Astrophysics and Space Sciences · Centro de Astrofísica da Universidade do Porto · European Southern Observatory · European Southern Observatory
Affiliation as printed
European Southern Observatory
Faculdade de Ciências da Universidade do Porto
Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP
ESA - Agence Spatiale Européenne = European Space Agency (Agence spatiale européenne (ESA) 8-10, rue Mario Nikis F-75015 Paris - France)
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National Institute for Astrophysics · Istituto Nazionale di Fisica Nucleare, Sezione di Torino · University of Turin · Osservatorio Astrofisico di Torino
Affiliation as printed
Dipartimento di Fisica, Università degli Studi di Torino
INAF-Osservatorio Astrofisico di Torino
INFN-Sezione di Torino
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Leiden University · European Space Agency · Leiden Observatory · European Space Research and Technology Centre
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European Space Agency/ESTEC
Leiden Observatory, Leiden University
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National Institute for Astrophysics · Osservatorio Astrofisico di Torino
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INAF-Osservatorio Astrofisico di Torino
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Universitat Autònoma de Barcelona · Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas · Port d'Informació Científica
Affiliation as printed
Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT)
Port d’Informació Científica, Campus UAB
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RWTH Aachen University · Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
Affiliation as printed
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
Institute for Theoretical Particle Physics and Cosmology (TTK), RWTH Aachen University
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National Institute for Astrophysics · Astronomical Observatory of Rome
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INAF-Osservatorio Astronomico di Roma
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics
Affiliation as printed
INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
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National Institute for Astrophysics · Istituto Nazionale di Fisica Nucleare · Istituto Nazionale di Fisica Nucleare, Sezione di Napoli · Astronomical Observatory of Capodimonte
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INAF-Osservatorio Astronomico di Capodimonte
INFN section of Naples
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University of Hawaiʻi at Mānoa · University of Hawaii System
Affiliation as printed
Institute for Astronomy, University of Hawaii
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Affiliation as printed
Dipartimento di Fisica e Astronomia “Augusto Righi” – Alma Mater Studiorum Università di Bologna
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Instituto de Astrofísica de Canarias
Affiliation as printed
Instituto de Astrofísica de Canarias
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European Space Agency · University of Edinburgh · Royal Observatory
Affiliation as printed
Institute for Astronomy, University of Edinburgh, Royal Observatory
ESA - Agence Spatiale Européenne = European Space Agency (Agence spatiale européenne (ESA) 8-10, rue Mario Nikis F-75015 Paris - France)
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University of Manchester · Laboratoire d’Astrophysique de Marseille
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Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, University of Manchester
LAM - Laboratoire d'Astrophysique de Marseille (Pôle de l'Étoile Site de Château-Gombert 38, rue Frédéric Joliot-Curie 13388 Marseille cedex 13 - France)
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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
European Space Agency/ESRIN
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Centre National de la Recherche Scientifique · Aix-Marseille Université · Institut de Physique des 2 Infinis de Lyon
Affiliation as printed
Aix-Marseille Université, CNRS, CNES, LAM
IP2I Lyon - Institut de Physique des 2 Infinis de Lyon (Campus LyonTech-la Doua Bâtiment Paul DIRAC 4 Rue Enrico Fermi 69622 Villeurbanne Cedex - France)
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Institut de Ciències del Cosmos · Universitat de Barcelona · Institució Catalana de Recerca i Estudis Avançats
Affiliation as printed
Institució Catalana de Recerca i Estudis Avançats (ICREA)
Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona (IEEC-UB)
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Centre National de la Recherche Scientifique · Institut National de Physique Nucléaire et de Physique des Particules · Institut de Physique des 2 Infinis de Lyon
Affiliation as printed
UCB Lyon 1, CNRS/IN2P3, IUF, IP2I Lyon
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Affiliation as printed
Mullard Space Science Laboratory, University College London
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University of Lisbon · Institute of Astrophysics and Space Sciences
Affiliation as printed
Departamento de Física, Faculdade de Ciências, Universidade de Lisboa
Instituto de Astrofísica e Ciências do Espaço, Faculdade de Ciências, Universidade de Lisboa
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Affiliation as printed
Department of Astronomy, University of Geneva
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Institut d'Astrophysique Spatiale · National Institute for Astrophysics · Trieste Astronomical Observatory
Affiliation as printed
INAF-Osservatorio Astronomico di Trieste
IAS - Institut d'astrophysique spatiale (Bâtiment 121 91405 ORSAY CEDEX - France)
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Affiliation as printed
Mullard Space Science Laboratory, University College London
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Centre National de la Recherche Scientifique · Université Paris-Saclay · Institut d'Astrophysique Spatiale
Affiliation as printed
Université Paris-Saclay, CNRS, Institut d’astrophysique spatiale
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Affiliation as printed
Department of Astronomy, University of Geneva
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University of Edinburgh · Royal Observatory
Affiliation as printed
Institute for Astronomy, University of Edinburgh, Royal Observatory
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European Space Astronomy Centre · Centre de physique des particules de Marseille
Affiliation as printed
ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo
CPPM - Centre de Physique des Particules de Marseille (163, avenue de Luminy - Case 902 - 13288 Marseille cedex 09 - France)
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Istituto Nazionale di Fisica Nucleare, Sezione di Padova · Istituto Nazionale di Fisica Nucleare
Affiliation as printed
INFN-Padova
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Centre National de la Recherche Scientifique · Institut National de Physique Nucléaire et de Physique des Particules · Aix-Marseille Université · Centre de physique des particules de Marseille
Affiliation as printed
Aix-Marseille Université, CNRS/IN2P3, CPPM
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Ludwig-Maximilians-Universität München · Max Planck Institute for Extraterrestrial Physics
Affiliation as printed
Max Planck Institute for Extraterrestrial Physics
Universitäts-Sternwarte München, Fakultät für Physik, Ludwig-Maximilians-Universität München
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National Institute for Astrophysics · Institut de Physique des 2 Infinis de Lyon · Institute for Space Astrophysics and Planetology
Affiliation as printed
INAF-Istituto di Astrofisica e Planetologia Spaziali
IP2I Lyon - Institut de Physique des 2 Infinis de Lyon (Campus LyonTech-la Doua Bâtiment Paul DIRAC 4 Rue Enrico Fermi 69622 Villeurbanne Cedex - France)
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics
Affiliation as printed
INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
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Centre National de la Recherche Scientifique · Institut National de Physique Nucléaire et de Physique des Particules · Lyon 1 Université · Institut de Physique des 2 Infinis de Lyon
Affiliation as printed
Université Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics · Istituto Nazionale di Fisica Nucleare, Sezione di Bologna · Centre de physique des particules de Marseille
Affiliation as printed
INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
INFN-Bologna
CPPM - Centre de Physique des Particules de Marseille (163, avenue de Luminy - Case 902 - 13288 Marseille cedex 09 - France)
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Universitat Politècnica de Catalunya · Institute of Space Sciences · Institut d'Estudis Espacials de Catalunya
Affiliation as printed
Institut d’Estudis Espacials de Catalunya (IEEC), Edifici RDIT, Campus UPC
Institute of Space Sciences (ICE, CSIC), Campus UAB
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Centre National de la Recherche Scientifique · Institut National de Physique Nucléaire et de Physique des Particules · Aix-Marseille Université · Centre de physique des particules de Marseille
Affiliation as printed
Aix-Marseille Université, CNRS/IN2P3, CPPM
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National Institute for Astrophysics · Trieste Astronomical Observatory
Affiliation as printed
INAF-Osservatorio Astronomico di Trieste
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics
Affiliation as printed
INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
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National Institute for Astrophysics
Affiliation as printed
INAF-IASF Milano
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National Institute for Astrophysics
Affiliation as printed
INAF-IASF Milano
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National Institute for Astrophysics · Trieste Astronomical Observatory · Centre de physique des particules de Marseille
Affiliation as printed
INAF-Osservatorio Astronomico di Trieste
CPPM - Centre de Physique des Particules de Marseille (163, avenue de Luminy - Case 902 - 13288 Marseille cedex 09 - France)
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Ludwig-Maximilians-Universität München
Affiliation as printed
University Observatory, LMU Faculty of Physics
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Centre National de la Recherche Scientifique · Institut National de Physique Nucléaire et de Physique des Particules · Aix-Marseille Université · Centre de physique des particules de Marseille
Affiliation as printed
Aix-Marseille Université, CNRS/IN2P3, CPPM
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University of Edinburgh · Royal Observatory
Affiliation as printed
Institute for Astronomy, University of Edinburgh, Royal Observatory
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics · Istituto Nazionale di Fisica Nucleare, Sezione di Bologna
Affiliation as printed
INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
INFN-Sezione di Bologna
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Max Planck Institute for Extraterrestrial Physics
Affiliation as printed
Max Planck Institute for Extraterrestrial Physics
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