Local Sheet

The Local Sheet is a flattened structure of nearby galaxies that includes the Local Group and lies along the boundary of the Local Void.

Local Group: The galaxy group containing the Milky Way, Andromeda Galaxy, Triangulum Galaxy, and dozens of smaller galaxies. The Local Sheet contains this group near its center.
Peculiar velocity: A celestial object's velocity relative to the smooth expansion of the universe. These motions help map the Local Sheet’s flow pattern.
Galaxy redshift survey: A systematic measurement of galaxy positions and redshifts across a region of sky. Redshift surveys supply distances and motions used to map the Local Sheet.
Milky Way: The barred spiral galaxy that contains the Solar System. It is one of the Local Group galaxies embedded in the Local Sheet.
Local Void: A large, relatively empty region of space adjacent to the Local Sheet. The sheet forms part of this void’s boundary.
Hubble flow: The apparent recession of distant galaxies caused by the expansion of the universe. Separating this expansion from local motion clarifies the sheet’s dynamics.
Tully–Fisher relation: An empirical relation connecting a spiral galaxy’s luminosity to its rotation speed. It provides distance estimates that help map nearby galaxy structures.
Andromeda Galaxy: The large spiral galaxy nearest the Milky Way and the most massive member of the Local Group. It is a major member of the group within the sheet.
Virgo Cluster: A massive cluster of galaxies in the constellation Virgo, near the center of the Virgo Supercluster. Its gravitational influence helps shape motions around the Local Sheet.
Void expansion: The growth of underdense cosmic regions as surrounding matter flows away from them. Expansion of the Local Void contributes to motions around the sheet.

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