The Coma I Group is a

group of galaxies A galaxy group or group of galaxies (GrG) is an aggregation of galaxies comprising about 50 or fewer gravitationally bound members, each at least as luminous as the Milky Way (about 1010 times the luminosity of the Sun); collections of galaxies ...

located about away in the constellation

Coma Berenices Coma Berenices is an ancient asterism in the northern sky, which has been defined as one of the 88 modern constellations. It is in the direction of the fourth galactic quadrant, between Leo and Boötes, and it is visible in both hemisphere ...

. The brightest member of the group is NGC 4725. The Coma I Group is rich in

spiral galaxies Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''elliptical Elliptical may mean: * having the shape of an ellipse, or more broadly, any oval shape ** in botany, having an elliptic leaf shape ** of aircraft wings, having an elliptical planform * characterised by ellipsis (the omission of words), or by conc ...

and

lenticular galaxies A lenticular galaxy (denoted S0) is a type of galaxy intermediate between an elliptical (denoted E) and a spiral galaxy in galaxy morphological classification schemes. It contains a large-scale disc but does not have large-scale spiral arms. L ...

. Coma I lies in the foreground of the more distant

Coma A coma is a deep state of prolonged unconsciousness in which a person cannot be awakened, fails to respond normally to painful stimuli, light, or sound, lacks a normal wake-sleep cycle and does not initiate voluntary actions. Coma patients exhi ...

and Leo clusters and is located within the

Virgo Supercluster The Virgo Supercluster (Virgo SC) or the Local Supercluster (LSC or LS) is a mass concentration of galaxies containing the Virgo Cluster and Local Group, which itself contains the Milky Way and Andromeda galaxies, as well as others. At least ...

. The Coma I Group is currently infalling into the

Virgo Cluster The Virgo Cluster is a large cluster of galaxies whose center is 53.8 ± 0.3 Mly (16.5 ± 0.1 Mpc) away in the constellation Virgo. Comprising approximately 1,300 (and possibly up to 2,000) member galaxies, the cluster forms the heart of the lar ...

and will eventually merge with it.

Structure

The Coma I Group appears to consist of two main subgroups, a denser subgroup centered on NGC 4274 and NGC 4278, and looser one surrounding

NGC 4565 NGC 4565 (also known as the Needle Galaxy or Caldwell 38) is an edge-on spiral galaxy about 30 to 50 million light-years away in the constellation Coma Berenices. It lies close to the North Galactic Pole and has a visual magnitude of approximatel ...

as suggested by De Vaucouleurs. However, Gregory and Thompson (1977) found no clear evidence for two distinct subgroups in Coma I. They noted a slight density enhancement around NGC 4274 with the rest of the members of Coma I uniformly distributed to the southeast of this density enhancement. They also noted a central barlike structure with a minor axis of and a major axis of . P. Fouque et al. and A. M. Garcia et al. both list the Coma I group consisting of two subgroups centered on NGC 4274 and

. Additionally, Gibson et al. suggests that another association, the Coma II Group which is centered on NGC 4725 is associated with the Coma I Group. In 2000, Ferrarese et al. defined the Coma II Group as containing 5 galaxies, namely NGC 4494, NGC 4562,

, NGC 4725, and NGC 4747. Also, it was found that these 5 galaxies which make up the Coma II Group have radial velocities in the narrow range of 1190 to 1395 km/s which is larger than the range of galaxies that are part of the Coma I group which have ranges of 600 to 1000 km/s. The nearby NGC 4631 Group is sometimes listed in some catalogs as being part of the Coma I Group, while other catalogs list the group as being separate from the Coma I Group.

Members

The table below lists galaxies that have been commonly and consistently identified as group members in the Nearby Galaxies Catalog, the survey of Fouque et al., the Lyons Groups of Galaxies (LGG) Catalog, and the three group lists created from the Nearby Optical Galaxy sample of Giuricin et al. Other possible member galaxies (galaxies listed in only one or two of the lists from the above references) include IC 3215, IC 3247, MCG 5-29- 66, NGC 4080, NGC 4150,

NGC 4308 NGC 4308 is an elliptical galaxy in the constellation Coma Berenices. It is a member of the Coma I Group The Coma I Group is a group of galaxies located about away in the constellation Coma Berenices. The brightest member of the group is NG ...

, NGC 4455, NGC 4509, NGC 4534, NGC 4627,

NGC 4631 NGC 4631 (also known as the Whale Galaxy or Caldwell 32) is a barred spiral galaxy in the constellation Canes Venatici. This galaxy's slightly distorted wedge shape gives it the appearance of a herring or a whale, hence its nickname. Because t ...

, NGC 4656, NGC 4670, UGC 6900, UGC 7007, UGC 7300, UGC 7428,

UGC 7438 UGC may refer to: Science and technology * Universal gravitational constant G, in physics * Uppsala General Catalogue, an astronomical catalogue of galaxies * UGC, a codon for cysteine * Unique games conjecture, a conjecture in computational comp ...

UGC 7673 UGC may refer to: Science and technology * Universal gravitational constant G, in physics * Uppsala General Catalogue, an astronomical catalogue of galaxies * UGC, a codon for cysteine * Unique games conjecture, a conjecture in computational comp ...

, UGC 7916 and UGCA 294.

Nearby groups

The center of the

( M87) lies about from the Coma I Group.

References

{{DEFAULTSORT:Coma I Virgo Supercluster Coma Berenices Galaxy clusters Ursa Major (constellation) Coma I Group

Structure

Members

Nearby groups

See also

References