Intrinsic alignment demographics for next-generation lensing: revealing galaxy property trends with DESI Y1 direct measurements
Year: 2026
Type: article
Abstract: ABSTRACT We present direct measurements of the intrinsic alignments (IA) of over 2 million spectroscopic galaxies using DESI Data Release 1 and imaging from four lensing surveys: DES, HSC, KiDS, and SDSS. In this uniquely data-rich regime, we take initial steps towards a more tailored IA modelling approach by building a library of IA measurements across colour, luminosity, stellar mass, and redshift. We map the dependence between galaxy type – in terms of rest-frame colour, strength of the $4000~\mathrm{\mathring{\rm A}}$ break, and specific star formation rate – and IA amplitude; the bluest galaxies have an alignment consistent with zero, across low ($0.05\lt z\lt 0.5$) and high ($0.8\lt z\lt 1.55$) redshifts. In order to construct cosmic shear samples that are minimally impacted by IA but maintain maximum sample size and statistical power, we map the dependence of alignment with colour purity. Red, quenched galaxies are strongly aligned and the amplitude of the signal increases with luminosity, which is tightly correlated with stellar mass in our catalogues. For DESI galaxies between $0\lt z\lt 1.5$, trends in luminosity and colour alone are sufficient to explain the alignments we measure – with no need for an explicit redshift dependence. In a companion paper (Jeffrey et al., in preparation), we perform detailed modelling of the IA signals with significant detections, including model comparison. Finally, to direct efforts for future IA measurements, we juxtapose the colour–magnitude–redshift coverage of existing IA measurements against modern and future lensing surveys.
Authors: J Siegel, J McCullough, A Amon, C Lamman, N Jeffrey, B Joachimi, H Hoekstra, S Heydenreich, A J Ross, J Aguilar, S Ahlen, D Bianchi, C Blake, D Brooks, F J Castander, T Claybaugh, A de la Macorra, J DeRose, P Doel, N Emas, S Ferraro, A Font-Ribera, J E Forero-Romero, E Gaztañaga, S Gontcho A Gontcho, G Gutierrez, K Honscheid, M Ishak, S Joudaki, R Kehoe, D Kirkby, T Kisner, A Krolewski, O Lahav, A Lambert, M Landriau, L Le Guillou, M E Levi, M Manera, A Meisner, R Miquel, J Moustakas, S Nadathur, J A Newman, G Niz, N Palanque-Delabrouille, W J Percival, A Porredon, F Prada, I Pérez-Ràfols, G Rossi, E Sanchez, C Saulder, D Schlegel, M Schubnell, A Semenaite, J Silber, D Sprayberry, Z Sun, G Tarlé, B A Weaver, R Zhou, H Zou
Institutions: Princeton University, University of Cambridge, Center for Astrophysics Harvard & Smithsonian, University College London, Leiden University, Leiden Observatory, University of California, Santa Cruz, The Ohio State University, Lawrence Berkeley National Laboratory, Boston University, University of Milan, Brera Astronomical Observatory, National Institute for Astrophysics, Swinburne University of Technology, Institute of Space Sciences, Institut d'Estudis Espacials de Catalunya, Universitat Politècnica de Catalunya, Universidad Nacional Autónoma de México, Brookhaven National Laboratory, University of California, Berkeley, Institute for High Energy Physics, Barcelona Institute of Science and Technology, Universidad de Los Andes, University of Portsmouth, University of Virginia, Fermi National Accelerator Laboratory, The University of Texas at Dallas, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Southern Methodist University, University of California, Irvine, Perimeter Institute, Centre National de la Recherche Scientifique, Sorbonne Université, Laboratoire de Physique Nucléaire et de Hautes Énergies, Institut National de Physique Nucléaire et de Physique des Particules, Universitat Autònoma de Barcelona, NSF NOIRLab, Institució Catalana de Recerca i Estudis Avançats, Siena College, University of Pittsburgh, Universidad de Guanajuato, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Université Paris-Saclay, CEA Paris-Saclay - Etablissement de Saclay, CEA Paris-Saclay, Institut de Recherche sur les Lois Fondamentales de l'Univers, University of Waterloo, Instituto de Astrofísica de Andalucía, Sejong University, Max Planck Institute for Extraterrestrial Physics, University of Michigan, Tsinghua University, Chinese Academy of Sciences, National Astronomical Observatories
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,046
Funders: National Science Foundation, U.S. Department of Energy, Gordon and Betty Moore Foundation, UK Research and Innovation, Ministerio de Ciencia, Innovación y Universidades, Deutsche Forschungsgemeinschaft, Nederlandse Organisatie voor Wetenschappelijk Onderzoek, Università degli Studi di Padova, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Office of Science, Science and Technology Facilities Council, Agencia Estatal de Investigación, Division of Astronomical Sciences, H2020 European Research Council, National Science Foundation Graduate Research Fellowship Program
Awards: G1044631029, G1105844351, G1175115578, G1286236842, G1813527838, G1863003419, G2262748287, UCL Astrophysics Consolidated Grant 2021-2024, G294895050, G300979063, G3083819904, G3362510713, Graduate Research Fellowship Program (GRFP), G3452655474, G3480869486, G3685081974, G419881185, G425668148, G42916606, G4501827968, G491712853, G498139845, G5080475149, G5635532810, G593054264, G618864540, G6652958823, G6876926712, G7084143925, Management and Operations of the National Optical Astronomy Observatory, G7395345766, G7549035430, G7805626310, G7863371703, G8178998509, G8345352404, G8497050386, G8667377315, G969889393
OpenAlex ID: W4415137757