In search for the Local Universe dynamical homogeneity scale with CF4++ peculiar velocities

TL;DR

This study updates the local Universe's cosmography using new peculiar velocity data, revealing the bulk flow, the scale of homogeneity, and refined supercluster structures, and publicly releases the CF4++ dataset and related fields.

Contribution

It introduces the CF4++ dataset and applies it to analyze local Universe dynamics, providing new insights into bulk flow, homogeneity scale, and supercluster structures.

Findings

Bulk flow of 315 ± 40 km/s at 150 Mpc/h

Homogeneity scale not reached at 200-300 Mpc/h

Refined shapes and boundaries of local superclusters

Abstract

This article explores an update to the cosmography of the local Universe within z=0.1, incorporating galaxy peculiar velocity datasets from the first data releases of WALLABY, FAST, and DESI surveys. The galaxies with peculiar velocities currently selected in each survey is 655, 4796, and 4191 respectively. The new CF4++ compendium enables a more comprehensive study of the nearby Universe bulk flow dynamics. We find a bulk flow of 315 \pm 40 km/s at 150 Mpc/h. This analysis additionally reveals that the dynamical scale of homogeneity is not yet reached in the interval [200-300] Mpc/h from the observer. This new data also refines the structure of local superclusters, revealing more spherical shapes and more clearly defined boundaries for key regions such as Great Attractor (Laniakea) and Coma. Very few measurements make a big difference in revealing the hidden Vela supercluster.To help colleagues obtain a peculiar velocity prediction for the object they are currently studying (SNIa, gravitational waves, etc.), we publicly release the CF4++ catalogue, as well as the reconstructed density and velocity fields used in this work.