Year: 2026
Type: preprint
Abstract: We measure the intrinsic alignment (IA) of galaxy multiplets with the large-scale tidal field traced by galaxy positions in DESI Data Release 2. Using the BGS, LRG, and ELG samples spanning $0.01 < z < 1.6$, we optimize the scales which define multiplets in each sample to minimize measurement noise. We measure multiplet tidal alignment $\mathcal{E}_+$ on scales beyond 100 $h^{-1}$Mpc in all samples, and detect alignment over 200 $h^{-1}$Mpc, up to 4.5$σ$ in the highest LRG redshift bin. We additionally present the multiplet shape-shape autocorrelation, $\mathcal{E}_{++}$, which is independent of galaxy bias and provides a consistency check of our NLA (nonlinear alignment) model. We do not detect a baryon acoustic feature in the projected estimator. We also find the alignment strength of multiplets is correlated with redshift and galaxy morphology. Multiplet alignment offers direct access to the tidal shear field in all galaxy samples, even where individual galaxy alignment cannot, and extends IA detection to the largest scales yet probed.
Source: arXiv (Cornell University)
Authors: Lamman, C., Aguilar, J., Ahlen, S., Aviles, A., Bianchi, D., Brooks, D., Rosell, A. Carnero, Castander, F. J., Claybaugh, T., de la Macorra, A., Eisenstein, D., Font-Ribera, A., Forero-Romero, J. E., Garcia-Quintero, C., Gaztañaga, E., Gutierrez, G., Honscheid, K., Ishak, M., Juneau, S., Karim, T., Kirkby, D., Lahav, O., Landriau, M., Levi, M. E., Manera, M., Meisner, A., Miquel, R., Nadathur, S., Noriega, H. E., Palanque-Delabrouille, N., Percival, W. J., Perdomo, M., Prada, F., Pérez-Ràfols, I., Ravoux, C., Ross, A. J., Rossi, G., Ruggeri, R., Samushia, L., Sanchez, E., Saulder, C., Schlegel, D., Schubnell, M., Silber, J., Siudek, M., Tarlé, G., Vaisakh, R., Weaver, B. A.
Institutions: Lawrence Berkeley National Laboratory, Boston University, Universidad Nacional Autónoma de México, University of Milan, Brera Astronomical Observatory, University College London, Universidad de La Laguna, Instituto de Astrofísica de Canarias, Institute of Space Sciences, Institut d'Estudis Espacials de Catalunya, Institució Catalana de Recerca i Estudis Avançats, Institute for High Energy Physics, Barcelona Institute of Science and Technology, Smithsonian Astrophysical Observatory, Center for Astrophysics Harvard & Smithsonian, Fermi National Accelerator Laboratory, The University of Texas at Dallas, University of Toronto, NSF NOIRLab, Universidad de Los Andes, The Ohio State University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, Gordon and Betty Moore Foundation, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Office of Science, Center for Cosmology and Astroparticle Physics, Ohio State University, Science and Technology Facilities Council, Agencia Estatal de Investigación, Division of Astronomical Sciences
Awards: G1044631029, G1175115578, G1286236842, G1813527838, G1863003419, G2262748287, Postdoctoral Fellowship: AAPF: Pioneering methods to connect galaxies with large-scale structure, G294895050, G300979063, G3083819904, G3452655474, G3480869486, G419881185, G425668148, G42916606, G4501827968, G498139845, G5080475149, G6652958823, G6876926712, G7084143925, Management and Operations of the National Optical Astronomy Observatory, G8345352404, G969889393
OpenAlex ID: W7213931346