ESO 146-5 (ESO 146-IG 005) is the designation given to a giant

interacting Interaction is action that occurs between two or more objects, with broad use in philosophy and the sciences. It may refer to: Science * Interaction hypothesis, a theory of second language acquisition * Interaction (statistics) * Interactions o ...

elliptical galaxy 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 ...

in the center of the Abell 3827 cluster. It is well noted due to its strong

gravitational lensing A gravitational lens is a distribution of matter (such as a cluster of galaxies) between a distant light source and an observer that is capable of bending the light from the source as the light travels toward the observer. This effect is known ...

effect, measurements of which show the galaxy to be one of the most massive in the known universe.

Physical characteristics

This interacting galaxy was found 1.4 billion light years away in the center of Abell 3827. A huge halo of stars is surrounding its interacting nuclei. It has immense gravity that holds the cluster together due to its mass. Its unusual shape has led to the conclusion that each one of the nuclei was formed from multiple collisions of smaller galaxies, and now the nuclei are merging to form a single huge elliptical galaxy.

Gravitational lensing A gravitational lens is a distribution of matter (such as a cluster of galaxies) between a distant light source and an observer that is capable of bending the light from the source as the light travels toward the observer. This effect is known ...

calculations appeared to show that there is a large

dark matter Dark matter is a hypothetical form of matter thought to account for approximately 85% of the matter in the universe. Dark matter is called "dark" because it does not appear to interact with the electromagnetic field, which means it does not a ...

mass lagging the top left nucleus, possibly explained by it being

self-interacting dark matter In astrophysics and particle physics, self-interacting dark matter (SIDM) is an alternative class of dark matter particles which have strong interactions, in contrast to the standard cold dark matter model (CDM). SIDM was postulated in 2000 as a ...

. commentar
The Possible First Signs of Self-interacting Dark Matter
/ref> However, this finding has since been discounted based on further observations and modelling of the cluster.

Mass

Observations from the

Gemini South Telescope The Gemini Observatory is an astronomical observatory consisting of two 8.1-metre (26.6 ft) telescopes, Gemini North and Gemini South, which are located at two separate sites in Hawaii and Chile, respectively. The twin Gemini telescopes prov ...

has shown that ESO 146-5 has gravitationally lensed two galaxies, a galaxy 2.7 billion light years away, and the other, 5.1 billion light years away. Using Einstein's theory of

general relativity General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics ...

, it was measured to be approximately 30 trillion solar masses, making it one of the most massive galaxies in the known universe.

Gallery

File:Our_Giant_Universe.jpg, This detailed image features

Abell 3827 ESO 146-5 (ESO 146-IG 005) is the designation given to a giant interacting elliptical galaxy in the center of the Abell 3827 cluster. It is well noted due to its strong gravitational lensing effect, measurements of which show the galaxy to be o ...

Physical characteristics

Mass

Gallery

References

Further reading