| Issue |
A&A
Volume 697, May 2025
Euclid on Sky
|
|
|---|---|---|
| Article Number | A6 | |
| Number of page(s) | 43 | |
| Section | Catalogs and data | |
| DOI | https://doi.org/10.1051/0004-6361/202450803 | |
| Published online | 30 April 2025 | |
Euclid: Early Release Observations – Programme overview and pipeline for compact- and diffuse-emission photometry★
1 Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM, 91191 Gif-sur-Yvette, France
2 INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy
3 Laboratoire d’Astrophysique de Bordeaux, CNRS and Université de Bordeaux, Allée Geoffroy St. Hilaire, 33165 Pessac, France
4 Institut universitaire de France (IUF), 1 rue Descartes, 75231 Paris Cedex 05, France
5 NRC Herzberg, 5071 West Saanich Rd, Victoria, BC V9E 2E7, Canada
6 Canada-France-Hawaii Telescope, 65-1238 Mamalahoa Hwy, Kamuela, HI 96743, USA
7 Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 1, 85748 Garching, Germany
8 Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Bd de l’Observatoire, CS 34229, 06304 Nice Cedex 4, France
9 Université de Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, 67000 Strasbourg, France
10 Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada
11 European Space Agency/ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands
12 Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands
13 Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
14 Department of Physics, Université de Montréal, 2900 Edouard Montpetit Blvd, Montréal, Québec H3T 1J4, Canada
15 Johns Hopkins University 3400 North Charles Street Baltimore, MD 21218, USA
16 Université Paris-Saclay, CNRS, Institut d’astrophysique spatiale, 91405, Orsay, France
17 ESAC/ESA, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Cañada, Madrid, Spain
18 Institut d’Astrophysique de Paris, UMR 7095, CNRS, and Sorbonne Université, 98 bis boulevard Arago, 75014 Paris, France
19 Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, 9000 Gent, Belgium
20 Centro de Astrobiología (CAB), CSIC-INTA, ESAC Campus, Camino Bajo del Castillo s/n, 28692 Villanueva de la Cañada, Madrid, Spain
21 Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
22 Aix-Marseille Université, CNRS, CNES, LAM, Marseille, France
23 INAF - Osservatorio Astronomico di Cagliari, Via della Scienza 5, 09047 Selargius (CA), Italy
24 David A. Dunlap Department of Astronomy & Astrophysics, University of Toronto, 50 St George Street, Toronto, Ontario M5S 3H4, Canada
25 Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
26 Departamento de Física Teórica, Atómica y Óptica, Universidad de Valladolid, 47011 Valladolid, Spain
27 Instituto de Astrofísica e Ciências do Espaço, Faculdade de Ciências, Universidade de Lisboa, Tapada da Ajuda, 1349-018 Lisboa, Portugal
28 INAF - Osservatorio Astronomico d’Abruzzo, Via Maggini, 64100 Teramo, Italy
29 INAF-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy
30 School of Mathematics and Physics, University of Surrey, Guildford, Surrey GU2 7XH, UK
31 Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK
32 Department of Mathematics and Physics E. De Giorgi, University of Salento, Via per Arnesano, CP-I93, 73100 Lecce, Italy
33 INFN, Sezione di Lecce, Via per Arnesano, CP-193, 73100 Lecce, Italy
34 INAF-Sezione di Lecce, c/o Dipartimento Matematica e Fisica, Via per Arnesano, 73100 Lecce, Italy
35 Instituto de Física de Cantabria, Edificio Juan Jordá, Avenida de los Castros, 39005 Santander, Spain
36 INAF-Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monteporzio Catone, Italy
37 Observatorio Nacional, Rua General Jose Cristino, 77-Bairro Imperial de Sao Cristovao, Rio de Janeiro 20921-400, Brazil
38 Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, Edifício C8, Campo Grande, 1749-016 Lisboa, Portugal
39 Instituto de Astrofísica e Ciências do Espaço, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
40 Universidad de La Laguna, Departamento de Astrofísica, 38206 La Laguna, Tenerife, Spain
41 Instituto de Astrofísica de Canarias, Vía Láctea, 38205 La Laguna, Tenerife, Spain
42 Universitäts-Sternwarte München, Fakultät für Physik, Ludwig-Maximilians-Universität München, Scheinerstrasse 1, 81679 München, Germany
43 Aix-Marseille Université, CNRS/IN2P3, CPPM, Marseille, France
44 School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
45 International Space University, 1 rue Jean-Dominique Cassini, 67400 Illkirch-Graffenstaden, France
46 Department of Astronomy, University of Florida, Bryant Space Science Center, Gainesville, FL 32611, USA
47 Department of Astronomy, University of Geneva, ch. d’Ecogia 16, 1290 Versoix, Switzerland
48 INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
49 Institute of Physics, Laboratory of Astrophysics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny, 1290 Versoix, Switzerland
50 Department of Physics, Centre for Extragalactic Astronomy, Durham University, South Road, Durham DH1 3LE, UK
51 Department of Physics, Institute for Computational Cosmology, Durham University, South Road, Durham DH1 3LE, UK
52 Astrophysics Research Centre, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa
53 School of Mathematics, Statistics & Computer Science, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa
54 National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
55 Department of Astrophysics/IMAPP, Radboud University, PO Box 9010, 6500 GL Nijmegen, The Netherlands
56 Aurora Technology for European Space Agency (ESA), Camino bajo del Castillo, s/n, Urbanizacion Villafranca del Castillo, Villanueva de la Cañada, 28692 Madrid, Spain
57 HE Space for European Space Agency (ESA), Camino bajo del Castillo, s/n, Urbanizacion Villafranca del Castillo, Villanueva de la Cañada, 28692 Madrid, Spain
58 Universität Innsbruck, Institut für Astro- und Teilchenphysik, Technikerstr. 25/8, 6020 Innsbruck, Austria
59 INFN-Sezione di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy
60 Leiden Observatory, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
61 Departamento de Física de la Tierra y Astrofísica, Universidad Complutense de Madrid, Plaza de las Ciencias 2, 28040 Madrid, Spain
62 Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
63 Institute for Advanced Research, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
64 Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, Kashiwa, Chiba 277-8583, Japan
65 European Space Agency, 8-10 rue Mario Nikis, 75738 Paris Cedex 15, France
66 Niels Bohr Institute, University of Copenhagen, Jagtvej 128, 2200 Copenhagen, Denmark
67 Cosmic Dawn Center (DAWN), Denmark
68 Center for Frontier Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
69 Department of Physics, Graduate School of Science, Chiba University, 1-33 Yayoi-Cho, Inage-Ku, Chiba 263-8522, Japan
70 Space physics and astronomy research unit, University of Oulu, Pentti Kaiteran katu 1, 90014 Oulu, Finland
71 Centre de Recherche Astrophysique de Lyon, UMR5574, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 69230, Saint-Genis-Laval, France
72 European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany
73 Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA
74 School of Physics & Astronomy, University of Southampton, High-field Campus, Southampton SO17 1BJ, UK
75 School of Physical Sciences, The Open University, Milton Keynes, MK7 6AA, UK
76 Univ. Lille, CNRS, Centrale Lille, UMR 9189 CRIStAL, 59000 Lille, France
77 Leibniz-Institut für Astrophysik (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
78 INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy
79 Department of Astronomy, University of Massachusetts, Amherst, MA 01003, USA
80 INAF-Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, Italy
81 IFPU, Institute for Fundamental Physics of the Universe, via Beirut 2, 34151 Trieste, Italy
82 INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste TS, Italy
83 SISSA, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste TS, Italy
84 Dipartimento di Fisica e Astronomia, Università di Bologna, Via Gobetti 93/2, 40129 Bologna, Italy
85 INAF-Osservatorio Astronomico di Padova, Via dell’Osservatorio 5, 35122 Padova, Italy
86 Centre National d’Etudes Spatiales - Centre spatial de Toulouse, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France
87 Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, 16146, Genova, Italy
88 INFN-Sezione di Genova, Via Dodecaneso 33, 16146 Genova, Italy
89 Institut de Recherche en Astrophysique et Planétologie (IRAP), Université de Toulouse, CNRS, UPS, CNES, 14 Av. Edouard Belin, 31400 Toulouse, France
90 Department of Physics “E. Pancini”, University Federico II, Via Cinthia 6, 80126 Napoli, Italy
91 INFN section of Naples, Via Cinthia 6, 80126 Napoli, Italy
92 Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal
93 Faculdade de Ciências da Universidade do Porto, Rua do Campo de Alegre, 4150-007 Porto, Portugal
94 Dipartimento di Fisica, Università degli Studi di Torino, Via P. Giuria 1, 10125 Torino, Italy
95 INFN-Sezione di Torino, Via P. Giuria 1, 10125 Torino, Italy
96 INAF-Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese (TO), Italy
97 INAF-IASF Milano, Via Alfonso Corti 12, 20133 Milano, Italy
98 Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Avenida Complutense 40, 28040 Madrid, Spain
99 Port d’Informació Científica, Campus UAB, C. Albareda s/n, 08193 Bellaterra (Barcelona), Spain
100 Institute for Theoretical Particle Physics and Cosmology (TTK), RWTH Aachen University, 52056 Aachen, Germany
101 Institute of Space Sciences (ICE, CSIC), Campus UAB, Carrer de Can Magrans, s/n, 08193 Barcelona, Spain
102 Institut d’Estudis Espacials de Catalunya (IEEC), Edifici RDIT, Campus UPC, 08860 Castelldefels, Barcelona, Spain
103 Dipartimento di Fisica e Astronomia “Augusto Righi” - Alma Mater Studiorum Università di Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy
104 European Space Agency/ESRIN, Largo Galileo Galilei 1, 00044 Frascati, Roma, Italy
105 Université Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, Villeurbanne 69100, France
106 UCB Lyon 1, CNRS/IN2P3, IUF, IP2I Lyon, 4 rue Enrico Fermi, 69622 Villeurbanne, France
107 Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK
108 INAF-Istituto di Astrofisica e Planetologia Spaziali, via del Fosso del Cavaliere, 100, 00100 Roma, Italy
109 INFN-Padova, Via Marzolo 8, 35131 Padova, Italy
110 School of Physics, HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
111 Istituto Nazionale di Fisica Nucleare, Sezione di Bologna, Via Irnerio 46, 40126 Bologna, Italy
112 FRACTAL S.L.N.E., calle Tulipán 2, Portal 13 1A, 28231 Las Rozas de Madrid, Spain
113 Dipartimento di Fisica “Aldo Pontremoli”, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy
114 Institute of Theoretical Astrophysics, University of Oslo, PO Box 1029 Blindern, 0315 Oslo, Norway
115 Department of Physics, Lancaster University, Lancaster LA1 4YB, UK
116 Felix Hormuth Engineering, Goethestr. 17, 69181 Leimen, Germany
117 Technical University of Denmark, Elektrovej 327, 2800 Kgs. Lyngby, Denmark
118 Cosmic Dawn Center (DAWN), Denmark
119 NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
120 Department of Physics and Helsinki Institute of Physics, Gustaf Hällströmin katu 2, 00014 University of Helsinki, Finland
121 Université de Genève, Département de Physique Théorique and Centre for Astroparticle Physics, 24 quai Ernest-Ansermet, 1211 Genève 4, Switzerland
122 Department of Physics, PO Box 64, 00014 University of Helsinki, Finland
123 Helsinki Institute of Physics, Gustaf Hällströmin katu 2, University of Helsinki, Helsinki, Finland
124 Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
125 NOVA optical infrared instrumentation group at ASTRON, Oude Hoogeveensedijk 4, 7991PD Dwingeloo, The Netherlands
126 INFN-Sezione di Milano, Via Celoria 16, 20133 Milano, Italy
127 Universität Bonn, Argelander-Institut für Astronomie, Auf dem Hügel 71, 53121 Bonn, Germany
128 Dipartimento di Fisica e Astronomia “Augusto Righi” - Alma Mater Studiorum Università di Bologna, via Piero Gobetti 93/2, 40129 Bologna, Italy
129 Institut d’Astrophysique de Paris, 98bis Boulevard Arago, 75014, Paris, France
130 Institut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology, Campus UAB, 08193 Bellaterra (Barcelona), Spain
131 Department of Physics and Astronomy, University of Aarhus, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
132 Waterloo Centre for Astrophysics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
133 Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
134 Space Science Data Center, Italian Space Agency, via del Politecnico snc, 00133 Roma, Italy
135 Institute of Space Science, Str. Atomistilor, nr. 409 Măgurele, Ilfov, 077125, Romania
136 Institute for Particle Physics and Astrophysics, Dept. of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093 Zurich, Switzerland
137 Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova, Via Marzolo 8, 35131 Padova, Italy
138 Departamento de Física, FCFM, Universidad de Chile, Blanco Encalada 2008, Santiago, Chile
139 Satlantis, University Science Park, Sede Bld 48940, Leioa-Bilbao, Spain
140 Centre for Electronic Imaging, Open University, Walton Hall, Milton Keynes MK7 6AA, UK
141 Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, USA
142 Universidad Politécnica de Cartagena, Departamento de Electrónica y Tecnología de Computadoras, Plaza del Hospital 1, 30202 Cartagena, Spain
143 Centre for Information Technology, University of Groningen, PO Box 11044, 9700 CA Groningen, The Netherlands
144 INFN-Bologna, Via Irnerio 46, 40126 Bologna, Italy
145 INAF, Istituto di Radioastronomia, Via Piero Gobetti 101, 40129 Bologna, Italy
146 ICL, Junia, Université Catholique de Lille, LITL, 59000 Lille, France
147 Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
★★ Corresponding author; jc.cuillandre@cea.fr
Received:
20
May
2024
Accepted:
26
February
2025
The Euclid Early Release Observations (ERO) showcase Euclid’s capabilities in advance of its main mission by targeting 17 astronomical objects, including galaxy clusters, nearby galaxies, globular clusters, and star-forming regions. A total of 24 hours of observing time was allocated in the early months of operation, and the scientific community was engaged through an early public data release. We describe the development of the ERO pipeline to create visually compelling images while simultaneously meeting the scientific demands within months of launch by leveraging a pragmatic data-driven development strategy. The pipeline’s key requirements are to preserve the image quality and to provide flux calibration and photometry for compact and extended sources. The pipeline’s five pillars are removal of instrumental signatures, astrometric calibration, photometric calibration, image stacking, and the production of science-ready catalogues for both the VIS and NISP instruments. We report a point spread function (PSF) with a full width at half maximum of 0ʺ.16 in the optical IE-band and 0ʺ.49 in the near-infrared (NIR) bands YE, JE, and HE. Our VIS mean absolute flux calibration is accurate to about 1%, and the accuracy is 10% for NISP due to a limited calibration set; both instruments have considerable colour terms for individual sources. The median depth is 25.3 and 23.2 AB mag with a signal-to-noise ratio (S/N) of ten for galaxies, while it is 27.1 and 24.5 AB mag at an S/N of five for point sources for VIS and NISP, respectively. Euclid’s ability to observe diffuse emission is exceptional due to its extended PSF nearly matching a pure diffraction halo, the best ever achieved by a wide-field high-resolution imaging telescope. Euclid offers unparalleled capabilities for exploring the low-surface brightness (LSB) Universe across all scales, providing high precision within a wide field of view (FoV), and opening a new observational window in the NIR. Median surface-brightness levels of 29.5 and 27.9, AB mag arcsec−2 are achieved for VIS and NISP, respectively, for detecting a 10ʺ × 10ʺ extended feature at the 1 σ level.
Key words: space vehicles: instruments / techniques: image processing / techniques: photometric / catalogs / astrometry
© The Authors 2025
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This article is published in open access under the Subscribe to Open model. Subscribe to A&A to support open access publication.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.