Galaxy Cluster Labels
Overview
The Galaxy Cluster Labels dataset is a series of labels that mark where the large clusters of galaxies are in the nearby universe. These labels must be used in conjunction with the Tully Galaxies.
Some nearby galaxy clusters. The Milky Way, labeled “Home,” is located at the center of the grids and each point here is a galaxy akin to the Milky Way. Orange points are in more dense regions, and; therefore, trace the clustering in the local universe. Hovering above are several large structures, dominated by the Virgo Cluster at the center of the image. Stretching up from Virgo to the right of frame is the Ursa Major Filament. In the distance is the Centaurus Cluster, the Antila Cluster, and the Hydra Cluster.
Note
The Galaxy Cluster Labels are designed to be shown with the Tully Galaxies.
What Constitutes a Galaxy Cluster?
A cluster of galaxies can contain hundreds or thousands of galaxies. These member galaxies are bound by gravity and are the second-largest structures after superclusters. Within the cluster exists hot gas and dark matter. A typical cluster has a diameter of roughly 3 million to 15 million light years.
Clusters are often named for the constellation in the night sky where they appear. The Virgo Cluster appears in the constellation Virgo, from our point of view on Earth.
Structural Landscape—Notable Clusters
The large-scale structure of the universe is hierarchical in nature. Individual galaxies form small groups and larger galaxy clusters. These are organized into superclusters and filaments, and those, in turn, form larger meta structures like sheets and walls.
In our part of the universe, we are in the Local Group and the nearest large galaxy cluster is the Virgo Cluster, about 54 million light years from Earth. The Virgo Cluster is the heart of the larger Virgo Supercluster, of which the Milky Way and accompanying Local Group are members.
At roughly the same distance, but opposite the Milky Way from Virgo, is the Fornax Cluster. With fewer galaxies than Virgo, it is a rich, dynamic cluster with two lobes, one centered around a large elliptical galaxy NGC 1399, and the other lobe centered on a lenticular galaxy NGC 1316. This lobe is falling into the main lobe, and the interaction forces are causing star formation within its galaxies.
The Antila Cluster is the third-closest cluster, and part of the Hydra-Centaurus Supercluster. At about 133 million light years, the cluster is more dense and dominiated by a pair of elliptical galaxies rather than one massive elliptical. It contains about 230 galaxies.
The Centaurus Cluster has hundreds of galaxies and is about 170 million light years away. It is dominated by one, large elliptical galaxy, NGC 4696, and, along with the IC4329 Cluster and the Hydra Cluster makes up the bulk of the Hydra-Centaurus Supercluster.
Farther away, the Coma Cluster and Leo Cluster are the heart of the Coma Supercluster. The Coma Cluster is massive, containing over 1,000 galaxies, and it’s about 320 million light years away. It was the early example of observed gravitational anomalies, resulting in “unobserved mass,” thereby introducing the dark matter theory. This was discovered by Fritz Zwicky (1898–1974) in 1933, who found that galaxies were moving too fast to be bound by gravity from visible matter alone. It would be another fifty years before the dark matter hypothesis was widely accepted. Today, we know 90% of the mass of the cluster is dark matter.
The Norma Cluster is about 220 million light years away. It is near the center of the Great Attractor, an area of gravitational attraction where much of our part of the universe is moving toward, including the Virgo Cluster and the Milky Way. Because it is located near that band of light in the night sky we call the Milky Way, this cluster is severely obscured by gas and dust, making it difficult to see in visible light.
A view of the more distant clusters, including the Coma, Leo, Norma, and Perseus clusters.
Profiles
Dossier
Census: |
15 cluster labels |
|---|---|
Asset File: |
|
OpenSpace Version: |
2 |
Reference: |
Nearby Galaxy Catalog, Private communication, Brent Tully |
Prepared by: |
R. Brent Tully (U Hawaii), Stuart Levy (NCSA), Brian Abbott (AMNH) |
Source Version: |
1.02 |
License: |