# Cosmicflows-3: Cosmography of the Local Void

## TL;DR

This paper uses Cosmicflows-3 data to map the Local Void and its surrounding structures, revealing its interconnectedness, influence on galaxy motions, and the cosmic web's filamentary nature.

## Contribution

It provides the first detailed reconstruction of the Local Void's structure and its dynamical impact on the Local Group using Cosmicflows-3 data.

## Key findings

- The Local Void is interconnected with nearby large voids.
- The Local Void influences the Local Group's motion by 50%.
- Filamentary structures traverse the voids, connecting major galaxy clusters.

## Abstract

Cosmicflows-3 distances and inferred peculiar velocities of galaxies have permitted the reconstruction of the structure of over and under densities within the volume extending to 0.05c. This study focuses on the under dense regions, particularly the Local Void that lies largely in the zone of obscuration and consequently has received limited attention. Major over dense structures that bound the Local Void are the Perseus-Pisces and Norma-Pavo-Indus filaments separated by 8,500 km/s. The void network of the universe is interconnected and void passages are found from the Local Void to the adjacent very large Hercules and Sculptor voids. Minor filaments course through voids. A particularly interesting example connects the Virgo and Perseus clusters, with several substantial galaxies found along the chain in the depths of the Local Void. The Local Void has a substantial dynamical effect, causing a deviant motion of the Local Group of 200-250 km/s. The combined perturbations due to repulsion from the Local Void and attraction toward the Virgo Cluster account for about 50% of the motion of the Local Group in the rest frame given by the cosmic microwave background.