Cosmicflows-3: Cosmography of the Local Void
  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.
