Detection of the large-scale tidal field with galaxy multiplet alignment in the DESI Y1 spectroscopic survey

Journal Article · 04 October 2024 · Monthly Notices of the Royal Astronomical Society

DOI: https://doi.org/10.1093/mnras/stae2290 · OSTI ID:2472961

Lamman, Claire ; Eisenstein, Daniel ; Forero-Romero, Jaime E. ; Aguilar, Jessica Nicole; Ahlen, Steven ; Bailey, Stephen ; Bianchi, Davide ; Brooks, David; Claybaugh, Todd; de la Macorra, Axel ; Doel, Peter; Ferraro, Simone ; Font-Ribera, Andreu ; Gaztañaga, Enrique ; Gontcho A Gontcho, Satya ; Gutierrez, Gaston; Honscheid, Klaus; Howlett, Cullan ; Kremin, Anthony ; Lambert, Andrew ; Landriau, Martin ; Le Guillou, Laurent ; Levi, Michael E. ; Meisner, Aaron ; Miquel, Ramon; Moustakas, John ; Newman, Jeffrey A. ; Niz, Gustavo ; Prada, Francisco ; Pérez-Ràfols, Ignasi ; Ross, Ashley J. ; Rossi, Graziano; Sanchez, Eusebio ; Schubnell, Michael; Sprayberry, David; Tarlé, Gregory ; Vargas-Magaña, Mariana ; Weaver, Benjamin Alan; Zou, Hu

ABSTRACT We explore correlations between the orientations of small galaxy groups, or ‘multiplets’, and the large-scale gravitational tidal field. Using data from the Dark Energy Spectroscopic Instrument (DESI) Y1 survey, we detect the intrinsic alignment (IA) of multiplets to the galaxy-traced matter field out to separations of $$100\,h^{-1}$$ Mpc. Unlike traditional IA measurements of individual galaxies, this estimator is not limited by imaging of galaxy shapes and allows for direct IA detection beyond redshift $z=1$. Multiplet alignment is a form of higher order clustering, for which the scale-dependence traces the underlying tidal field and amplitude is a result of small-scale ($$\lt 1h^{-1}$$ Mpc) dynamics. Within samples of bright galaxies, luminous red galaxies (LRG) and emission-line galaxies, we find similar scale-dependence regardless of intrinsic luminosity or colour. This is promising for measuring tidal alignment in galaxy samples that typically display no IA. DESI’s LRG mock galaxy catalogues created from the A bacusS ummitN-body simulations produce a similar alignment signal, though with a 33 per cent lower amplitude at all scales. An analytic model using a non-linear power spectrum (NLA) only matches the signal down to 20 $$h^{-1}$$ Mpc. Our detection demonstrates that galaxy clustering in the non-linear regime of structure formation preserves an interpretable memory of the large-scale tidal field. Multiplet alignment complements traditional two-point measurements by retaining directional information imprinted by tidal forces, and contains additional line-of-sight information compared to weak lensing. This is a more effective estimator than the alignment of individual galaxies in dense, blue, or faint galaxy samples.

• Sponsoring Organization: USDOE
• Grant/Contract Number: SC0013718
• OSTI ID: 2472961
• Journal Information: Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 4 Vol. 534; ISSN 0035-8711
• Publisher: Oxford University PressCopyright Statement
• Country of Publication: United Kingdom
• Language: English