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arXiv · 2510.08353

Enhancing Multiplet Alignment Measurements with Imaging

Abstract

We demonstrate that measurements of the gravitational tidal field made with spectroscopic redshifts can be improved with information from imaging surveys. The average orientation of small groups of galaxies, or "multiplets" is correlated with large-scale structure and is used to measure the direction of tidal forces. Previously, multiplet intrinsic alignment has been measured in DESI using galaxies that have spectroscopic redshifts. The DESI Legacy Imaging catalog can be used to supplement multiplet catalogs. Our findings show that galaxy positions from the imaging catalog produce a measurement similar to the measurements made with only spectroscopic data. This demonstrates that imaging can improve our signal-to-noise ratio for multiplet alignment in DESI.

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Alexus Annika Kumwembe, Claire Lamman, Daniel Eisenstein, Jessica Nicole Aguilar, Steven Ahlen, Davide Bianchi, David Brooks, Todd Claybaugh, Andrei Cuceu, Axel de la Macorra, Biprateep Dey, Peter Doel, Andreu Font-Ribera, Jaime E. Forero-Romero, Enrique Gaztanaga, Satya Gontcho A Gontcho, Gaston Gutierrez, Mustapha Ishak, Jorge Jimenez, Dick Joyce, Robert Kehoe, Theodore Kisner, Ofer Lahav, Martin Landriau, Marc Manera, Ramon Miquel, Seshadri Nadathur, Nathalie Palanque-Delabrouille, Ignasi Perez-Rafols, Francisco Prada, Graziano Rossi, Eusebio Sanchez, David Schlegel, Hee-Jong Seo, Joseph Harry Silber, David Sprayberry, Gregory Tarle, Benjamin Alan Weaver. 2025-10-09. Enhancing Multiplet Alignment Measurements with Imaging. https://arxiv.org/abs/2510.08353

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