Radiation astronomy/Galaxy clusters

From Wikiversity
Jump to navigation Jump to search
The universe within 1 billion light-years (307 Mpc) of Earth is shown to contain the local superclusters, galaxy filaments and voids. Credit: Richard Powell.

"Galaxies and clusters of galaxies are not uniformly distributed in the Universe, instead they collect into vast clusters and sheets and walls of galaxies interspersed with large voids in which very few galaxies seem to exist. The map above shows many of these superclusters including the Virgo supercluster - the minor supercluster of which our galaxy is just a minor member. The entire map is approximately 7 percent of the diameter of the entire visible Universe."[1]

Bootes Supercluster[edit]

"There are a couple of [prominent] superclusters in Bootes over 800 million light years away but this region of the sky is more famous for the large Bootes Void that lies next to them."[1]

Centaurus Supercluster[edit]

"The nearest large supercluster[, the] Centaurus supercluster is a long supercluster containing four rich galaxy clusters - A3526, A3565, A3574 and A3581 [and] hundreds of smaller groups of galaxies. A3526 is the dominant cluster among these and lies 140 million light years away. Seen from a large distance, the Virgo and Hydra superclusters might look like appendages to the Centaurus supercluster. The Centaurus supercluster lies near the Great Attractor - a large collection of matter affecting the motion of our galaxy and others. It is obscured by the plane of our own galaxy, but it is [probably] the large cluster A3627 [...]."[1]

Coma Supercluster[edit]

"This is a small [...] supercluster about 300 million light years away. There are two very rich galaxy clusters here - A1367 and A1656, both containing thousands of galaxies. A1656 is [...] known as the Coma cluster, [...]. The Coma supercluster lies at the centre of The Great Wall, a vast filament of galaxies that stretches over hundreds of millions of light years, one end of which terminates on the Hercules supercluster."[1]

Corona Borealis Supercluster[edit]

"The most distant of the famous superclusters. It has long been recognised that there are a large number of rich galaxy clusters in this small constellation. A2065 is probably the dominant cluster here, but there are another nine or ten large clusters here which are also rich. The supercluster is about 1 billion light years away."[1]

Hercules Supercluster[edit]

"Two famous and prominant superclusters lie here. The smaller and nearer one is probably the most famous being dominated by two rich clusters - A2197 and A2199 that lie very close to each other. This supercluster lies 400 million light years away. The second supercluster is only slightly further - 500 million light years, but it is a lot bigger and contains lots of rich galaxy clusters scattered around hundreds of smaller galaxy groups."[1]

Horologium Supercluster[edit]

"This is a huge supercluster 900 million light years away. It is not as dense as the Shapley supercluster but it contains a large number of rich galaxy clusters scattered across half a billion light years making it one of the largest known superclusters. This is another region of the sky in which Harlow Shapley noticed an excess of galaxies. [...] In astronomy journals the Horologium supercluster is sometimes called the Horologium-Reticulum supercluster."[1]

Hydra Supercluster[edit]

This nearby supercluster "is very similar in size and shape to the Virgo supercluster. The Hydra supercluster is also dominated by one rich cluster of galaxies - A1060, [...]."[1]

Leo Supercluster[edit]

"Several large galaxy clusters on the border of Leo and Ursa Major at a distance of 450 million light years mark the presence of another large supercluster. The dominant clusters here are A1185 and A1228."[1]

Pavo-Indus Supercluster[edit]

"This is a fairly weak supercluster that marks one end of a long wall of galaxies that encompasses the Centaurus supercluster and probably the Virgo supercluster [...]. The Pavo-Indus supercluster contains three rich galaxy clusters - A3656, A3698 and A3742."[1]

Perseus-Pisces Supercluster[edit]

"This supercluster is a large sheet of galaxy groups scattered around three rich clusters - A262, A347 and A426. A426 [contains] thousands of galaxies."[1]

Pisces-Cetus Supercluster[edit]

"This is a region containing several major superclusters over 800 million light years [...]. There are several very large superclusters here forming long wall structures hundreds of millions of light years in length."[1]

Shapley Supercluster[edit]

"The Shapley supercluster is a massive supercluster [...], it is certainly one of the densest. There are two main concentrations - one at 500 million light years and a larger one at 650 million light years. There are at least twenty rich galaxy clusters among the thousands of galaxy groups in this supercluster, including three of the richest galaxy clusters known: A3558, A3559 and A3560."[1]

Sculptor Supercluster[edit]

"Two superclusters in the Sculptor and Phoenix regions of the sky mark the position of a very long wall of thousands of galaxy groups stretching over nearly a billion light years of space."[1]

Radios[edit]

This image has the radio image of Greg Taylor, NRAO, overlain on the X-ray image from Chandra. The radio source Hydra A originates in a galaxy near the center of the cluster. Optical observations show a few hundred galaxies in the cluster. Credit: NASA/CXC/SAO; Radio: NRAO.

References[edit]

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 Richard Powell (30 July 2006). The Universe within 1 billion Light Years The Neighbouring Superclusters. Atlas of the Universe. Retrieved 2018-04-01.