The Local Sheet or the Coma–Sculptor Cloud is a nearby galaxy filament and an extragalactic region of space where the Milky Way, the members of the Local Group, and other galaxies share a similar peculiar velocity. This region lies within a diameter of about , thick, and galaxies beyond that distance show markedly different velocities. The Local Group has only a relatively small peculiar velocity of with respect to the Local Sheet. Typical velocity dispersion of galaxies is only in the radial direction. Nearly all nearby bright galaxies belong to the Local Sheet. The Local Sheet is part of the Local Volume and is in the Virgo Supercluster (Local Supercluster). The Local Sheet forms a wall of galaxies delineating one boundary of the Local Void.
A significant component of the mean velocity of the galaxies in the Local Sheet appears as the result of the gravitational attraction of the Virgo Cluster of galaxies, resulting in a peculiar motion ~ toward the cluster. A second component is directed away from the center of the Local Void; an expanding region of space spanning an estimated that is only sparsely populated with galaxies. This component has a velocity of . The Local Sheet is inclined 8° from the Local Supercluster (Virgo Supercluster).
The so-called Council of Giants is a ring of twelve large galaxies surrounding the Local Group in the Local Sheet, with a radius of and its center located at away from the Sun. Ten of these are spirals, while the remaining two are ellipticals. The two ellipticals (Maffei 1 and Centaurus A) lie on opposite sides of the Local Group.
+ Galaxies in the "Council of Giants" Catalog ID Name Constellation Distance (Mly) Stellar mass * NGC 253 Sculptor Galaxy Sculptor 11 10.805 PGC 9892 Maffei 1 Cassiopeia 11 10.928 PGC 10217 Maffei 2 Cassiopeia 11 10.493 IC 342 Camelopardalis 11 10.302 NGC 3031 M 81 Ursa Major 12 10.905 NGC 3034 M 82 Ursa Major 11 10.573 NGC 4736 M 94 Canes Venatici 15 10.458 NGC 4826 M 64 Coma Berenices 16 10.496 NGC 5236 M 83 Hydra 16 10.642 NGC 5128 Centaurus A Centaurus 11 11.169 NGC 4945 Centaurus 12 10.528 ESO 97-G13 Circinus Galaxy Circinus 14 10.559
* The mass is given as the logarithm (base unspecified) of the mass in solar masses.
Location The Local Sheet is the co-moving part of the Coma-Sculptor Cloud, which was identified and described in 1987 by astronomer Brent Tully with colleague Richard Fisher in his book The Nearby Galaxies Atlas as Cloud 14. It is a huge prolate, filament and is mostly host to late-type galaxies, in contrast to the Virgo Cluster, in which more than half of the giant galaxies are early-type galaxies.
Tully maintains that the Coma-Sculptor Cloud and the Local Sheet do not quite overlap, as the Local Sheet comprises only the co-moving part of the Coma-Sculptor Cloud. McCall considers the two terms synonymous, referring to one and the same region.
See also Supergalactic coordinate system, the coordinate system taking the Local Sheet, the Supergalactic Plane, as its X–Y bases
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