The Antlia Cluster (or Abell S0636) is a

cluster of galaxies A galaxy cluster, or a cluster of galaxies, is a structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity, with typical masses ranging from 1014 to 1015 solar masses. They are the second-lar ...

located in the

Hydra–Centaurus Supercluster The Hydra-Centaurus Supercluster (SCl 128), or the Hydra and Centaurus Superclusters, is a supercluster in two parts, the closest neighbour of Virgo Supercluster. Hydra-Centaurus The cluster includes four large galaxy clusters in the Centaurus pa ...

. The Antlia Cluster is the third-nearest to the

Local Group The Local Group is the galaxy group that includes the Milky Way. It has a total diameter of roughly , and a total mass of the order of . It consists of two collections of galaxies in a "dumbbell" shape: the Milky Way and its satellites form ...

after 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

Fornax Cluster The Fornax Cluster is a cluster of galaxies lying at a distance of 19 megaparsecs (62 million light-years). It has an estimated mass of solar masses, making it the second richest galaxy cluster within 100 million light-years, after the consider ...

. Antlia's distance from

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

is to and can be viewed from Earth in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Antlia Antlia (; from Ancient Greek ''ἀντλία'') is a constellation in the Southern Celestial Hemisphere. Its name means " pump" in Latin and Greek; it represents an air pump. Originally Antlia Pneumatica, the constellation was established by N ...

. The Antlia Cluster should not be confused with the

Antlia Dwarf The Antlia Dwarf is a dwarf spheroidal/irregular galaxy. It lies about 1.3 Mpc (4.3 million light-years) from Earth in the constellation Antlia. It is the fourth and faintest member of the nearby Antlia-Sextans Group of galaxies. The gal ...

galaxy A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. ...

. Antlia is classified as a rare '' Bautz–Morgan type III'' cluster, meaning it has no central dominant (cD)

brightest cluster galaxy A brightest cluster galaxy (BCG) is defined as the brightest galaxy in a cluster of galaxies. BCGs include the most massive galaxies in the universe. They are generally elliptical galaxies which lie close to the geometric and kinematical center ...

. However, the cluster is dominated by two massive

elliptical galaxies An elliptical galaxy is a type of galaxy with an approximately ellipsoidal shape and a smooth, nearly featureless image. They are one of the four main classes of galaxy described by Edwin Hubble in his Hubble sequence and 1936 work ''The Real ...

NGC 3268 NGC 3268 is an elliptical galaxy in the constellation Antlia. It is a member of the Antlia Cluster, which lies about away. It was discovered on April 18, 1835 by the astronomer John Herschel Sir John Frederick William Herschel, 1st Baronet ...

and NGC 3258, and contains a total of about 234 galaxies. The cluster is very dense compared to other clusters such as Virgo and Fornax, thus containing early-type galaxies and a larger portion of dwarf ellipticals. The cluster is split into two

galaxy group 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 ...

s, ''the Northern subgroup'' gravitating around NGC 3268, and ''the Southern subgroup'' centered on NGC 3258. The cluster has an overall

redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in f ...

of z = 0.0087, implying that the cluster is, like most objects in the

Universe The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the universe. Acc ...

, receding from the

. Using the now-obsolete scientific satellite

ASCA ''Asca'' is a genus of mites with worldwide distribution in the family Ascidae Ascidae is a family of mites in the order Mesostigmata. Description Ascidae are mites characterised by: seta ''st4'' usually on unsclerotised cuticle, peritrem ...

X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

observations show that the cluster is almost

isothermal In thermodynamics, an isothermal process is a type of thermodynamic process in which the temperature ''T'' of a system remains constant: Δ''T'' = 0. This typically occurs when a system is in contact with an outside thermal reservoir, and a ...

, with a mean temperature of kT ~ 2.0 keV.

List of named objects in the Antlia Cluster

References

External links

* {{DEFAULTSORT:Antlia Cluster Galaxy clusters S0636 Abell richness class 0 Hydra-Centaurus Supercluster

List of named objects in the Antlia Cluster

See also

References

Further reading

External links