Minor axis 1.5 Mly (0.5 Mpc) Distance(co-moving) 0 Mly (0 Mpc) | Major axis 17 Mly (5 Mpc) Redshift 0.00 | |
The Local Sheet in astronomy is a nearby region of the observable universe where the Milky Way, the members of the Local Group and other galaxies share a similar peculiar velocity. This region lies within a radius of about 7 Mpc (23 Mly), 0.46 Mpc (1.5 Mly) thick, and galaxies beyond that distance show markedly different velocities. The Local Group has only a relatively small peculiar velocity of 7001660000000000000♠66 km⋅s−1 with respect to the Local Sheet. Typical velocity dispersion of galaxies within the Local Sheet is only 7001400000000000000♠40 km⋅s−1 in the radial direction. 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).
A significant component of the mean velocity of the galaxies in the Local Sheet comes as the result of the gravitational attraction of the Virgo Cluster of galaxies. This results in a peculiar motion of about 7002185000000000000♠185 km⋅s−1 toward the cluster. A second component is directed away from the center of the Local Void; an expanding region of space spanning an estimated 45 Mpc (150 Mly) that is only sparsely populated with galaxies. This component has a velocity of 7002259000000000000♠259 km⋅s−1. The Local Sheet is inclined 8° from the Local Supercluster (Virgo Supercluster).
The Council of Giants is a ring of twelve large galaxies surrounding the Local Group in the Local Sheet, with a radius of 3.75 Mpc (12.2 Mly). 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, and their formation may have prompted the development of the Local Group. The Local Sheet's own development outlines a concentration of dark matter in a filament.
* The mass is given as the logarithm of the mass in solar masses.