%0 Journal Article %T Euclid preparation - I. The Euclid Wide Survey %+ Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU) %+ Institut d'Astrophysique de Paris (IAP) %+ Istituto di Astrofisica Spaziale e Fisica cosmica - Bologna (IASF-Bo) %+ Université de Lisbonne %+ Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)) %+ European Space Astronomy Centre (ESAC) %+ Centre d'étude spatiale des rayonnements (CESR) %+ Institut de Physique des 2 Infinis de Lyon (IP2I Lyon) %+ Centre de Physique des Particules de Marseille (CPPM) %+ Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3) %+ Joseph Louis LAGRANGE (LAGRANGE) %+ AstroParticule et Cosmologie (APC (UMR_7164)) %+ Centre de Calcul de l'IN2P3 (CC-IN2P3) %+ Laboratoire d'Astrophysique de Marseille (LAM) %A Scaramella, R. %A Amiaux, J. %A Mellier, Y. %A Burigana, C. %A Carvalho, C. %A Cuillandre, J.-C. %A da Silva, A. %A Derosa, A. %A Dinis, J. %A Maiorano, E. %A Maris, M. %A Tereno, I. %A Laureijs, R. %A Boenke, T. %A Buenadicha, G. %A Dupac, X. %A Gaspar Venancio, L. %A Gómez-Álvarez, P. %A Hoar, J. %A Lorenzo Alvarez, J. %A Racca, G. %A Saavedra-Criado, G. %A Schwartz, J. %A Vavrek, R. %A Schirmer, M. %A Aussel, H. %A Azzollini, R. %A Cardone, V. %A Cropper, M. %A Ealet, A. %A Garilli, B. %A Gillard, W. %A Granett, B. %A Guzzo, L. %A Hoekstra, H. %A Jahnke, K. %A Kitching, T. %A Maciaszek, T. %A Meneghetti, M. %A Miller, L. %A Nakajima, R. %A Niemi, S. %A Pasian, F. %A Percival, W. %A Pottinger, S. %A Sauvage, M. %A Scodeggio, M. %A Wachter, S. %A Zacchei, A. %A Aghanim, N. %A Amara, A. %A Auphan, T. %A Auricchio, N. %A Awan, S. %A Balestra, A. %A Bender, R. %A Bodendorf, C. %A Bonino, D. %A Branchini, E. %A Brau-Nogue, S. %A Brescia, M. %A Candini, G. %A Capobianco, V. %A Carbone, C. %A Carlberg, R. %A Carretero, J. %A Casas, R. %A Castander, F. %A Castellano, M. %A Cavuoti, S. %A Cimatti, A. %A Cledassou, R. %A Congedo, G. %A Conselice, C. %A Conversi, L. %A Copin, Y. %A Corcione, L. %A Costille, A. %A Courbin, F. %A Degaudenzi, H. %A Douspis, M. %A Dubath, F. %A Duncan, C. %A Dusini, S. %A Farrens, S. %A Ferriol, S. %A Fosalba, P. %A Fourmanoit, N. %A Frailis, M. %A Franceschi, E. %A Franzetti, P. %A Fumana, M. %A Gillis, B. %A Giocoli, C. %A Grazian, A. %A Grupp, F. %A Haugan, S. %A Holmes, W. %A Hormuth, F. %A Hudelot, P. %A Kermiche, S. %A Kiessling, A. %A Kilbinger, M. %A Kohley, R. %A Kubik, B. %A Kümmel, M. %A Kunz, M. %A Kurki-Suonio, H. %A Lahav, O. %A Ligori, S. %A Lilje, P. %A Lloro, I. %A Mansutti, O. %A Marggraf, O. %A Markovic, K. %A Marulli, F. %A Massey, R. %A Maurogordato, S. %A Melchior, M. %A Merlin, E. %A Meylan, G. %A Mohr, J. %A Moresco, M. %A Morin, B. %A Moscardini, L. %A Munari, E. %A Nichol, R. %A Padilla, C. %A Paltani, S. %A Peacock, J. %A Pedersen, K. %A Pettorino, V. %A Pires, S. %A Poncet, M. %A Popa, L. %A Pozzetti, L. %A Raison, F. %A Rebolo, R. %A Rhodes, J. %A Rix, H.-W. %A Roncarelli, M. %A Rossetti, E. %A Saglia, R. %A Schneider, P. %A Schrabback, T. %A Secroun, A. %A Seidel, G. %A Serrano, S. %A Sirignano, C. %A Sirri, G. %A Skottfelt, J. %A Stanco, L. %A Starck, J. %A Tallada-Crespí, P. %A Tavagnacco, D. %A Taylor, A. %A Teplitz, H. %A Toledo-Moreo, R. %A Torradeflot, F. %A Trifoglio, M. %A Valentijn, E. %A Valenziano, L. %A Verdoes Kleijn, G. %A Wang, Y. %A Welikala, N. %A Weller, J. %A Wetzstein, M. %A Zamorani, G. %A Zoubian, J. %A Andreon, S. %A Baldi, M. %A Bardelli, S. %A Boucaud, A. %A Camera, S. %A Di Ferdinando, D. %A Fabbian, G. %A Farinelli, R. %A Galeotta, S. %A Graciá-Carpio, J. %A Maino, D. %A Medinaceli, E. %A Mei, S. %A Neissner, C. %A Polenta, G. %A Renzi, A. %A Romelli, E. %A Rosset, C. %A Sureau, F. %A Tenti, M. %A Vassallo, T. %A Zucca, E. %A Baccigalupi, C. %A Balaguera-Antolínez, A. %A Battaglia, P. %A Biviano, A. %A Borgani, S. %A Bozzo, E. %A Cabanac, R. %A Cappi, A. %A Casas, S. %A Castignani, G. %A Colodro-Conde, C. %A Coupon, J. %A Courtois, H. %A Cuby, J. %A de la Torre, S. %A Desai, S. %A Dole, H. %A Fabricius, M. %A Farina, M. %A Ferreira, P. %A Finelli, F. %A Flose-Reimberg, P. %A Fotopoulou, S. %A Ganga, K. %A Gozaliasl, G. %A Hook, I. %A Keihanen, E. %A Kirkpatrick, C. %A Liebing, P. %A Lindholm, V. %A Mainetti, G. %A Martinelli, M. %A Martinet, N. %A Maturi, M. %A Mccracken, H. %A Metcalf, R. %A Morgante, G. %A Nightingale, J. %A Nucita, A. %A Patrizii, L. %A Potter, D. %A Riccio, G. %A Sánchez, A. %A Sapone, D. %A Schewtschenko, J. %A Schultheis, M. %A Scottez, V. %A Teyssier, R. %A Tutusaus, I. %A Valiviita, J. %A Viel, M. %A Vriend, W. %A Whittaker, L. %< avec comité de lecture %@ 0004-6361 %J Astronomy and Astrophysics - A&A %I EDP Sciences %V 662 %P A112 %8 2022-06 %D 2022 %Z 2108.01201 %R 10.1051/0004-6361/202141938 %Z Sciences of the Universe [physics] %Z Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] %Z Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] %Z Sciences of the Universe [physics]/Astrophysics [astro-ph]Journal articles %X Euclid is a mission of the European Space Agency that is designed to constrain the properties of dark energy and gravity via weak gravitational lensing and galaxy clustering. It will carry out a wide area imaging and spectroscopy survey (the Euclid Wide Survey: EWS) in visible and near-infrared bands, covering approximately 15 000 deg 2 of extragalactic sky in six years. The wide-field telescope and instruments are optimised for pristine point spread function and reduced stray light, producing very crisp images. This paper presents the building of the Euclid reference survey: the sequence of pointings of EWS, deep fields, and calibration fields, as well as spacecraft movements followed by Euclid as it operates in a step-and-stare mode from its orbit around the Lagrange point L2. Each EWS pointing has four dithered frames; we simulated the dither pattern at the pixel level to analyse the effective coverage. We used up-to-date models for the sky background to define the Euclid region-of-interest (RoI). The building of the reference survey is highly constrained from calibration cadences, spacecraft constraints, and background levels; synergies with ground-based coverage were also considered. Via purposely built software, we first generated a schedule for the calibrations and deep fields observations. On a second stage, the RoI was tiled and scheduled with EWS observations, using an algorithm optimised to prioritise the best sky areas, produce a compact coverage, and ensure thermal stability. The result is the optimised reference survey RSD_2021A, which fulfils all constraints and is a good proxy for the final solution. The current EWS covers ≈14 500 deg 2 . The limiting AB magnitudes (5 σ point-like source) achieved in its footprint are estimated to be 26.2 (visible band I E ) and 24.5 (for near infrared bands Y E , J E , H E ); for spectroscopy, the H α line flux limit is 2 × 10 −16 erg −1 cm −2 s −1 at 1600 nm; and for diffuse emission, the surface brightness limits are 29.8 (visible band) and 28.4 (near infrared bands) mag arcsec −2 . %G English %2 https://hal.science/hal-03866201v2/document %2 https://hal.science/hal-03866201v2/file/aa41938-21.pdf %L hal-03866201 %U https://hal.science/hal-03866201 %~ IN2P3 %~ IRD %~ OBSPM %~ CEA %~ INSU %~ METEO %~ UNICE %~ UNIV-TLSE3 %~ CPPM %~ APC %~ CNRS %~ UNIV-AMU %~ UNIV-LYON1 %~ CNES %~ LAM %~ OMP %~ OMP-CESR %~ OMP-IRAP %~ OCA %~ LAGRANGE %~ OSU-INSTITUT-PYTHEAS %~ IAP %~ DSM-IRFU %~ IRFU-AIM %~ CEA-UPSAY %~ PSL %~ UNIV-PARIS-SACLAY %~ UNIV-COTEDAZUR %~ CEA-DRF %~ SORBONNE-UNIVERSITE %~ SORBONNE-UNIV %~ SU-SCIENCES %~ IP2I %~ UDL %~ UNIV-LYON %~ CMS %~ IPM %~ PHABIO %~ MANOIR %~ THEORIE %~ COSMOLOGIE %~ MATNUC %~ NEUTRINOS_IP2I %~ UNIV-PARIS %~ UNIVERSITE-PARIS %~ UP-SCIENCES %~ TEST-HALCNRS %~ OBSPM-PSL %~ UNIVERSITE-PARIS-SACLAY %~ ALICE_IP2I %~ ONDES_GRAVITATIONNELLES %~ SU-TI %~ GS-PHYSIQUE %~ CC-IN2P3 %~ ALLIANCE-SU %~ MATICE %~ UNIV-UT3 %~ UT3-INP %~ UT3-TOULOUSEINP