Euclid preparation
D. Navarro-GironésInstitut d’Estudis Espacials de Catalunya (IEEC), Edifici RDIT, Campus UPCI. TutusausInstitute of Space Sciences (ICE, CSIC), Campus UABM. CrocceInstitute of Space Sciences (ICE, CSIC), Campus UABS. Gouyou BeauchampsInstitut d’Estudis Espacials de Catalunya (IEEC), Edifici RDIT, Campus UPCR PaviotUniversité Paris CitéB. JoachimiDepartment of Physics and Astronomy, University College LondonJ. Ruiz-ZapateroDepartment of Physics and Astronomy, University College LondonD. SciottiINAF-Osservatorio Astronomico di RomaN. TessoreMullard Space Science Laboratory, University College LondonJ. BlazekDepartment of Physics, Northeastern UniversityG Cañas-HerreraInstitute for Astronomy, University of Edinburgh, Royal ObservatoryP. CarrilhoDepartment of Physics, Astronomy and Mathematics, University of HertfordshireJ.M. Coloma-NadalInstitute of Space Sciences (ICE, CSIC), Campus UABHenk HoekstraLeiden Observatory, Leiden UniversityA. PorredonCentro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT)B. AltieriESAC/ESAS. AndreonINAF-Osservatorio Astronomico di BreraC. BaccigalupiINAF-Osservatorio Astronomico di TriesteMarco BaldiUniversity of BolognaS. BardelliINAF-Osservatorio di Astrofisica e Scienza dello Spazio di BolognaA. BivianoINAF-Osservatorio Astronomico di TriesteE. BranchiniINFN-Sezione di GenovaM. BresciaDepartment of Physics “E. Pancini”, University Federico IIS. CameraDipartimento di Fisica, Università degli Studi di TorinoV. CapobiancoINAF-Osservatorio Astrofisico di TorinoC. CarboneINAF-IASF MilanoV. F. CardoneINFN-Sezione di RomaJ. CarreteroPort d’Informació Científica, Campus UABF. J. CastanderInstitute of Space Sciences (ICE, CSIC), Campus UABM. CastellanoNational Institute for AstrophysicsG. CastignaniINAF-Osservatorio di Astrofisica e Scienza dello Spazio di BolognaS. CavuotiINFN section of NaplesK. C. ChambersInstitute for Astronomy, University of HawaiiC Colodro-CondeInstituto de Astrofísica de CanariasG. CongedoUniversity of EdinburghChristopher J. ConseliceJodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, University of ManchesterL. ConversiESAC/ESAY. CopinCentre National de la Recherche ScientifiqueF. CourbinInstitució Catalana de Recerca i Estudis Avançats (ICREA)H. M. CourtoisCentre National de la Recherche ScientifiqueA. Da SilvaDepartamento de Física, Faculdade de Ciências, Universidade de LisboaH. DegaudenziDepartment of Astronomy, University of GenevaG. De LuciaINAF-Osservatorio Astronomico di TriesteH. DoleUniversité Paris-Saclay, CNRS, Institut d’astrophysique spatialeF. DubathDepartment of Astronomy, University of GenevaC. A. J. DuncanUniversity of EdinburghX DupacESAC/ESAS. EscoffierCentre de physique des particules de MarseilleM. FarinaINAF-Istituto di Astrofisica e Planetologia SpazialiR FarinelliINAF-Osservatorio di Astrofisica e Scienza dello Spazio di BolognaS. FarrensCEA Paris-SaclayS. FerriolCentre National de la Recherche ScientifiqueF. Finelli⋆INAF-Osservatorio di Astrofisica e Scienza dello Spazio di BolognaP. FosalbaInstitute of Space Sciences (ICE, CSIC), Campus UABS. FotopoulouSchool of Physics, HH Wills Physics Laboratory, University of BristolN. FourmanoitCentre de physique des particules de MarseilleM. FrailisINAF-Osservatorio Astronomico di TriesteE. FranceschiINAF-Osservatorio di Astrofisica e Scienza dello Spazio di BolognaM. FumanaINAF-IASF MilanoS. GaleottaINAF-Osservatorio Astronomico di TriesteKoshy GeorgeB. GillisUniversity of EdinburghC. GiocoliINAF-Osservatorio di Astrofisica e Scienza dello Spazio di BolognaJ. Gracia-CarpioMax Planck Institute for Extraterrestrial PhysicsA. GrazianINAF-Osservatorio Astronomico di PadovaF GruppUniversitäts-Sternwarte München, Fakultät für Physik, Ludwig-Maximilians-Universität MünchenS. V. H. HauganInstitute of Theoretical Astrophysics, University of OsloW. HolmesJet Propulsion Laboratory, California Institute of TechnologyF. HormuthFelix Hormuth EngineeringA. HornstrupCosmic Dawn Center (DAWN)K. JahnkęMax-Planck-Institut für AstronomieS. KermicheAix-Marseille Université, CNRS/IN2P3, CPPMA. KiesslingJet Propulsion Laboratory, California Institute of TechnologyM. KilbingerCEA Paris-SaclayB. KubikUniversité Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822Konrad KuijkenLeiden Observatory, Leiden UniversityM. KunzUniversité de Genève, Département de Physique Théorique and Centre for Astroparticle PhysicsH. Kurki‐SuonioDepartment of Physics, University of HelsinkiA. M. C. Le BrunLaboratoire d’etude de l’Univers et des phenomenes eXtremes, Observatoire de Paris, Université PSL, Sorbonne Université, CNRSS. LigoriINAF-Osservatorio Astrofisico di TorinoP. B. LiljeInstitute of Theoretical Astrophysics, University of OsloV. LindholmHelsinki Institute of PhysicsI. LloroSKAOG. MainettiCentre de Calcul de l’IN2P3/CNRSO. MansuttiINAF-Osservatorio Astronomico di TriesteO. MarggrafUniversität Bonn, Argelander-Institut für AstronomieM. MartinelliINAF-Osservatorio Astronomico di RomaN. MartinetAix-Marseille Université, CNRS, CNES, LAMF. MarulliINFN-Sezione di BolognaE. MedinaceliINAF-Osservatorio di Astrofisica e Scienza dello Spazio di BolognaM. MeneghettiINAF-Osservatorio di Astrofisica e Scienza dello Spazio di BolognaE. MerlinINAF-Osservatorio Astronomico di RomaG. MeylanInstitute of Physics, Laboratory of Astrophysics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Observatoire de SauvernyA. MoraTelespazio UK S.L. for European Space Agency (ESA)M. MorescoINAF-Osservatorio di Astrofisica e Scienza dello Spazio di BolognaL. MoscardiniDipartimento di Fisica e Astronomia “Augusto Righi” – Alma Mater Studiorum Università di BolognaR. NakajimaUniversität Bonn, Argelander-Institut für AstronomieC. NeissnerInstitut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology, Campus UABS.-M. NiemiEuropean Space Research and Technology CentreC PadillaInstitut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology, Campus UAB
2026en
ABI
Abstract
The Euclid galaxy survey will provide unprecedented constraints on cosmology, but achieving unbiased results will require an optimal characterisation and mitigation of systematic effects. The intrinsic alignment (IAs) of galaxies are one of the dominant contaminants of the weak lensing (WL) and galaxy-galaxy lensing (GGL) probes. In this work, we assess IA modelling choices for Euclid DR1 3 × 2 pt analyses by using synthetic data vectors and comparing the performance of the two most commonly used IA models, non-linear alignment (NLA) and tidal alignment tidal torquing (TATT), along with several variations. Our analyses combine three perspectives: (i) the constraining power on the IA and cosmological parameters for each IA model, (ii) the bias that results when the IA analysis model differs from the model used to generate the synthetic data vector, and (iii) the degeneracies between IAs and photometric redshift (photo- z ) nuisance parameters. Amongst the IA models analysed, the redshift-dependent TATT model ( z TATT) provides the most flexible description of IAs, with a constraining power similar to simpler IA models, making it a suitable choice for Euclid DR1 3 × 2 pt analyses.