User:Marshallsumter/Radiation astronomy1/Galaxy clusters

"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."

Galaxies
The radiation astronomy of galaxies generally is about the galaxy as a radiated or radiation emitting astronomical object. The stellar aspects of individual galaxies are in galaxies of stars.

A galaxy is often perceived as a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter. Galaxies range in size from dwarfs with just a few hundred million stars to giants with one hundred trillion  stars, each orbiting its galaxy's center of mass.

Galaxies are categorized according to their visual morphology as elliptical, spiral, or irregular.

The number of galaxies in the observable universe has increased from a previous estimate of 200 billion ($200,000,000,000$) to a suggested 2 trillion ($2,000,000,000,000$) or more, containing more stars than all the grains of sand on planet Earth.

Intergalactic medium
The intergalactic medium (IGM) is a rarefied plasma.

"The Chandra observations found evidence for the massive and hot intergalactic medium filaments by noting a slight dimming in distant quasar X-rays likely caused by hot gas absorption."

Theoretical galaxy clusters
Def. a "cluster of hundreds of galaxies" is called a galaxy cluster.

Def. a "massive, thread-like formation of gravitationally bound galaxies forming the boundaries between large voids in the universe" is called a galaxy filament.

Def. an "extended group of clusters of galaxies" is called a supercluster.

Def. a "group of galaxies that hold together gravitationally" is called a galaxy group.

Def. a "number of galaxies that become a galaxy group over time" is called a protogroup.

"Where galaxies live in the universe and how they interact with their surroundings (the intergalactic medium that surrounds them) and each other are major influences on their ability to form stars. But precisely how this so-called environment dictates the life and death of galaxies remains a mystery."

"Galaxy clusters are the most massive and most extreme environments in the universe, containing many hundreds or even thousands of galaxies. Where you have mass, you also have gravity and the huge gravitational forces present in clusters accelerates galaxies to great speeds, often thousands of kilometres-per-second, and superheats the plasma in between galaxies to temperatures so high that it glows with X-ray light."

"As galaxies fall through clusters, the intergalactic plasma can rapidly remove their gas in a violent process called ram pressure stripping. When you remove the fuel for star formation, you effectively kill the galaxy, turning it into a dead object in which no new stars are formed."

"In addition, the high temperature of clusters can stop hot gas cooling and condensing onto galaxies. In this case, the gas in the galaxy isn't actively removed by the environment but is consumed as it forms stars. This process leads to a slow, inexorable shut down in star formation known, somewhat morbidly, as starvation or strangulation."

The image on the right "shows the region where the ancient galactic structure was found. The blue shading shows the area it covers. The red objects in the zoomed-in bits are the 12 galaxies."

"The discovery, which could help explain the shape of the modern cosmos, reveals 12 galaxies that existed in a clump 13 billion years ago — just about 700 million years after the Big Bang. We can see them now because they're so far away in the expanding universe (13 billion light-years) that their starlight is only now reaching Earth. One of the galaxies, a mammoth named Himiko after a mythological Japanese queen, was discovered a decade ago [...]."

"Himiko sits at the edge of the system, which [is called] a "protocluster" because it's so small and ancient compared to most of the clusters we can see in the universe."

"It is reasonable to find a protocluster near a massive object, such as Himiko. However, we're surprised to see that Himiko was located not in the center of the protocluster but on the edge, 500 million light-years away from the center."

"[T]here is a clear trend that the star-formation activity of galaxies tends to be lower in high-density environment than low-density environment."

""[P]rotoclusters" like this one from the early eons of the universe are rarely found and are poorly understood."

Zwicky classifications
Galaxy clusters are classified according to the concentration of galaxy members as a function of cluster diameter dividing them into categories:
 * 1) highly compact, with any specific clump having more than ten galaxies,
 * 2) medium compact, a single or several concentrations are optically separated by diameters,
 * 3) open, no concentration detected at all.

Bautz-Morgan classifications
The Bautz–Morgan classification is a criteria based on the number and hierarchy of the brightest dominant members within cluster boundaries based on their Hubble sequence morphology.


 * A type I cluster is dominated by a bright, large, supermassive cD galaxy.
 * A type II cluster contains elliptical galaxies whose brightness relative to the cluster is intermediate to that of type I and type III.
 * A type III cluster has no remarkable members, such as the Virgo Cluster. Type III has two subdivisions, type IIIE and type IIIS
 * Type IIIE clusters do not contain many giant spirals
 * Type IIIS clusters contain many giant spirals
 * The deprecated type IV was for clusters whose brightest members were predominantly spirals.

Rood-Sastry classifications
Galaxy clusters are classified according to their richness based on the distribution of the ten brightest members and morphology as a "Tuning Fork" in the following categories:
 * 1) cD (super-giant) - cluster with a remarkable brightest member as central dominant.
 * 2) B (binary) - Two super-giants galaxies separated by ≤ 10 diameters of the larger galaxy (generally with a filament connection between them).
 * 3) L (line) - Three or more galaxies as top brightest members in line.
 * 4) C (core-halo) - Four or more top brightest separated around the centre.
 * 5) F (flat) - Several of the top ten brightest members in flattened configuration.
 * 6) I (irregular) - Galaxies that are distributed with no well-defined centre.

Oemler's classifications
Fractions of clusters with spirals (Sps), no spirals (S0s) and ellipticals (Es) subdivided into spiral-rich and spiral-poor.

Abell 2029
Abell 2029 is composed of thousands of galaxies (optical image, right) enveloped in a gigantic cloud of hot gas (X-ray image, left), and an amount of dark matter equivalent to more than a hundred trillion Suns. Both the gas and the galaxies are confined to the cluster primarily by the gravity of the dark matter. If this galaxy cluster is a representative sample of the universe, the Chandra observation indicates that 70 to 90 percent of the mass of the universe consists of dark matter - mysterious particles left over from the dense early universe that interact with each other and "normal" matter only through gravity.

Abell 2029 or A2029 is a large galaxy cluster 315 megaparsecs (1.027 billion light-years) away in the constellation Virgo. A2029 is a Bautz–Morgan classification type I cluster due to its large central galaxy, IC 1101.

Abell 2065
Abell 2065, a highly concentrated galaxy cluster in the constellation of Corona Borealis contains over 400 member galaxies, the brightest of which are 16th magnitude, is more than one billion light-years from Earth. On a larger scale still, Abell 2065, along with Abell 2061, Abell 2067, Abell 2079, Abell 2089, and Abell 2092, make up the Corona Borealis Supercluster.

Canes Venatici II Group
The 'Canes II Group or Canes Venatici II Group (CVn II Group) is a group of galaxies about 26.1 million light-years away from Earth in the Local Supercluster. The largest galaxy within the cluster is Messier 106 (NGC 4258), which is a barred spiral galaxy.

Canes II is directly behind Canes I, which makes it difficult to show which galaxy belongs in which cluster.

M51 Group
The M51 Group, which includes the Whirlpool Galaxy (M51) and the Sunflower Galaxy (M63),   is located to the southeast of the M101 Group. The distances to the NGC 5866 Group, M51 and M101 groups (as determined from the distances to the individual member galaxies) are similar, which suggests that the M51 Group, the M101 Group, and the NGC 5866 Group are actually part of a single large, loose, elongated group.

M81 Group
The M81 Group is a galaxy group in the constellations Ursa Major and Camelopardalis that includes the galaxies Messier 81 and Messier 82, as well as several other galaxies with high apparent brightnesses. The approximate center of the group is located at a distance of 3.6 Mpc, making it one of the nearest groups to the Local Group. The group is estimated to have a total mass of (1.03 ± 0.17) Solar mass. The M81 Group, the Local Group, and other nearby groups all lie within the Virgo Supercluster (i.e. the Local Supercluster).

The table below lists galaxies that have been identified as associated with the M81 Group by I. D. Karachentsev.

Note that the object names used in the above table differ from the names used by Karachentsev. New General Catalogue (NGC), Index Catalogue (IC), Uppsala General Catalogue (UGC), and Principal Galaxies Catalogue (PGC) numbers have been used in many cases to allow for easier referencing.

M94 Group
The M94 Group (Canes Venatici I Group) is a loose, extended group of galaxies located about 13 million light-years away in the constellations Canes Venatici and Coma Berenices. The group is one of many groups that lies within the Virgo Supercluster (i.e. the Local Supercluster) and one of the closest groups to the Local Group.

Although the galaxies in this cluster appear to be from a single large cloud-like structure, many of the galaxies within the group are only weakly gravitationally bound, and some have not yet formed stable orbits around the center of this group. Instead, most of the galaxies in this group appear to be moving with the expansion of the universe.

The table below lists galaxies that have been consistently identified as group members in the Nearby Galaxies Catalog, the Lyons Groups of Galaxies (LGG) Catalog, and the three group lists created from the Nearby Optical Galaxy sample.

M101 Group
The M101 Group is a loose group of galaxies located in Ursa Major. The group is named after the brightest galaxy in the group, the Pinwheel Galaxy (M101). Most of the other members of the group are companions of the Pinwheel Galaxy. The group itself is one of many located within the Virgo Supercluster (i.e. the Local Supercluster).

The table below lists galaxies that have been 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 members galaxies (galaxies listed in only one or two of the lists from the above references) include the irregular galaxies NGC 5238 and UGC 8508.

M109 Group
The M109 Group (aka the NGC 3992 Group or Ursa Major cloud) is a group of galaxies about 1022 m (55 million lys) away in the constellation Ursa Major.

The table below lists galaxies that have been consistently identified as group members in the Nearby Galaxies Catalog, the survey of Fouque et al., the Lyons Groups of Galaxies (LGG) Catalogue, and the three group lists created from the Nearby Optical Galaxy sample of Giuricin et al.

NGC 1023 Group
The NGC 1023 group is a group of galaxies about 20.6 million light-years from Earth in the Local Supercluster along with the Local Group.

NGC 2997 Group
The NGC 2997 group is a group of galaxies about 24.8 million light-years from Earth containing NGC 2997 as a member and is a group in the Local Supercluster along with the Local Group.

NGC 4038 Group
The table below lists galaxies that have been 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.

The NGC 4038 group along with other galaxies and galaxy groups are part of the Crater Cloud which is a component of the Virgo Supercluster.

NGC 4065 Group
The NGC 4065 Group is a group of galaxies located about 100 Mpc in the constellation Coma Berenices. The group's brightest member is NGC 4065 and located in the Coma Supercluster.

The group is dominated by mostly elliptical galaxies with only 15 to 31 percent of the members being spiral galaxies.

The NGC 4065 Group exhibits bimodal X-ray emission with one peak on the galaxies NGC 4061 and NGC 4065 and the other on NGC 4066.

NGC 5866 Group
The NGC 5866 Group is located to the northwest of the M101 group.

Antlia Cluster
The Antlia Cluster (or Abell S0636) is a galaxy cluster|cluster of galaxies located in the Hydra-Centaurus Supercluster. The Antlia Cluster is the third nearest to the Local Group after the Virgo Cluster and Fornax Cluster. Antlia's distance from Earth is 40.5 Mpc to 40.9 Mpc and can be viewed from Earth in the constellation Antlia. The Antlia Cluster should not be confused with the Antlia Dwarf Galaxy.

Antlia is classified as a rare Bautz-Morgan type III cluster, meaning it has no central dominant (cD) brightest cluster galaxy. However, the cluster is dominated by two massive elliptical galaxies, NGC 3268 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 groups, The Northern subgroup gravitating around NGC 3268, and the Southern subgroup centered on NGC 3258.

The cluster has an overall redshift of z = 0.0087, implying that the cluster is, like most objects in the Universe, receding from the Local Group. Using the now-obsolete scientific satellite Advanced Satellite for Cosmology and Astrophysics (ASCA), X-ray observations show that the cluster is almost isothermal, with a mean temperature of kT ~ 2.0 keV.

Members of cluster:


 * NGC 3267
 * NGC 3568
 * NGC 3258
 * NGC 3269
 * NGC 3271
 * NGC 3258A
 * NGC 3258B
 * NGC 3260
 * NGC 3267
 * NGC 3268
 * NGC 3273

Centaurus Cluster
The cluster consists of two different sub-groups of galaxies with different velocities. Cen 30 is the main subgroup containing NGC 4696. Cen 45 which is centered on NGC 4709, is moving at 1500 km/s relative to Cen 30, and is believed to be merging with the main cluster.

Hydra A galaxy cluster
] A large cloud of hot gas extends throughout the Hydra A galaxy cluster.

Hydra Cluster
The Hydra Cluster (or Abell 1060) is a galaxy cluster that contains 157 bright galaxies, appearing in the constellation Hydra. The cluster spans about ten million light years and has an unusually high proportion of dark matter. The cluster is part of the Hydra-Centaurus Supercluster located 158 million light years from earth. The cluster's largest galaxies are elliptical galaxies NGC 3309 and NGC 3311 and the spiral galaxy NGC 3312 all having a diameter of about 150,000 light years. In spite of a nearly circular appearance on the sky, there is evidence in the galaxy velocities for a clumpy, three-dimensional distribution.

Leo Cluster
The Leo Cluster (Abell 1367) is a galaxy cluster about 330 million light-years distant (z = 0.022 ) in the constellation Leo, with at least 70 major galaxies. NGC 3842 is the brightest member of this cluster. Along with the Coma Cluster, it is one of the two major clusters comprising the Coma Supercluster, which in turn is part of the CfA2 Great Wall, hundreds of millions light years long and one of the largest known structures in the universe.

The Leo cluster and its stars are probably younger than most comparable clusters in the universe and evolve at a different pace.

In the center of NGC 3842 the black hole is 9.7 billion times more massive than our sun.

A "hot zone" exists where stars are unable to maintain their gas long enough to properly form.

Subpopulations within the Leo Cluster:
 * 1) elliptical galaxies that seem to be roughly as old as the universe,
 * 2) red-sequence lenticular (lens shaped) galaxies whose ages are directly tied to their mass,
 * 3) galaxies where star formation is still taking place, and are morphologically distributed.

Ursa Major Cluster
"The Ursa Major Cluster is the most poorly defined, with a velocity dispersion of only 148 km s−1 and a virial radius of 880 kpc [...], and contains essentially only late-type galaxies distributed with no particular concentration toward any center."

"The Ursa Major Cloud contains the Ursa Major Cluster."

"Optical images	have been acquired in the B, RC, IC (C=Cousins) passbands for all 79 galaxies with a variety of CCD and telescope combinations."

"The 79 galaxies that are accepted lie within 7.5° of α = 11h56.9m, δ = +49°22′ and have measured velocities, Vhelio + 300sinℓcosb, between 700 and 1210 km s−1."

The cluster includes NGC 3726, NGC 3769, NGC 3782, NGC 3870, NGC 3877, NGC 3893, NGC 3896, NGC 3906, NGC 3917, NGC 3931, NGC 3928, NGC 3938, NGC 3949, NGC 3953, NGC 3985, NGC 3972, NGC 3982, NGC 3985, NGC 3990, NGC 3992, NGC 3998, NGC 4010, NGC 4013, NGC 4026, NGC 4051, NGC 4085, NGC 4088, NGC 4100, NGC 4102, NGC 4111, NGC 4117, NGC 4118, NGC 4138, NGC 4143, NGC 4157, NGC 4183, NGC 4217, NGC 4218, NGC 4220, NGC 4346, and NGC 4389.

Virgo Cluster
The Virgo Cluster is a galaxy cluster whose center is 53.8 ± 0.3 Mly (16.5 ± 0.1 Mpc) away in the constellation Virgo. Comprising approximately 1300 (and possibly up to 2000) member galaxies, the cluster forms the heart of the larger Virgo Supercluster, of which the Local Group (containing our Milky Way) is a member. The Local Group actually experiences the mass of the Virgo Supercluster as the Virgocentric flow, where the Virgo Cluster's mass is 1.2 solar masses out to 8 degrees of the cluster's center or a radius of about 2.2 Mpc.

The elliptical galaxy Messier 87 is located in the center of the cluster.

The cluster is a fairly heterogeneous mixture of spirals and ellipticals. The spiral galaxies of the cluster appear to be distributed in an oblong prolate filament, approximately four times as long as it is wide, stretching along the line of sight from the Milky Way. The elliptical galaxies are more centrally concentrated than the spiral galaxies.

The cluster is an aggregrate of at least three separate subclumps: Virgo A, centered on M87, a second centered on the galaxy M86, and Virgo B, centered on the elliptical galaxy M49, with a Virgo C subcluster, centered on the galaxy M60 as well as a LVC (Low Velocity Cloud) subclump, centered on the large spiral galaxy NGC 4216.

Of all of the subclumps, Virgo A, formed by a mixture of elliptical, lenticular, and (usually) gas-poor spiral galaxies, is the dominant one, with a mass of approximately 1014 solar masses, which is approximately an order of magnitude larger than the other two subclumps. The three subgroups are in the process of merging to form a larger single cluster and are surrounded by other smaller galaxy clouds, mostly composed of spiral galaxies, known as N Cloud, S Cloud, and Virgo E that are in the process of infalling to merge with them, plus other farther isolated galaxies and galaxy groups (like the galaxy cloud Coma I) that are also attracted by the gravity of Virgo to merge with it in the future. This strongly suggests the Virgo cluster is a dynamically young cluster that is still forming.

Other two nearby aggregations known as M Cloud, W Cloud, and W' Cloud seem to be background systems independent of the main cluster.

As with many other rich galaxy clusters, Virgo's intracluster medium is filled with a hot, rarefied plasma at temperatures of 30 million K that emits X-Rays. Within the intracluster medium (ICM) are found a large number of intergalactic stars (up to 10% of the stars in the cluster), including some planetary nebulae. It is theorized that these were expelled from their home galaxies by interactions with other galaxies. The ICM also contains some globular clusters,  possibly stripped off dwarf galaxies, and even at least one star formation H II region.

Boötes Supercluster
"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."

The Bootes Supercluster is a super cluster of galaxies located in the direction of the Bootes constellation bordering the Super Corona of the Northern Crown with which it is probably connected by a filament of galaxies, and with the Void of Bootes, an area of the universe with a minimum concentration of galaxies (less than one hundred have been identified) with a diameter of about 300 million light years. In Bootes there are two concentrations of galaxy clusters called SCL 349 and SCL 351, placed respectively at 830 million and 1 billion light years from Earth.

BOSS Great Wall
The BOSS Great Wall, a supercluster complex identified using the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey (SDSS), was discovered in early 2016. The BOSS Great Wall is one of the largest superstructures in the observable universe.

The large complex has a mean redshift of z ~ 0.47 (z times Hubble length ≈ 6800 million light years). It consists of two elongated superclusters, two large superclusters, and several smaller superclusters as well. The elongated superclusters form galaxy walls, with the larger of the two having a diameter of 186/h Mpc (supercluster A in the figure); the second wall's being 173/h Mpc (supercluster B), where the other two main superclusters are moderately large, having diameters of 91/h Mps and 64/h Mpc (superclusters D and C, respectively).

The superstructure is roughly 1 billion light years in diameter, and has a total mass approximately 10,000 times the Milky Way galaxy. It contains at least 830 visible galaxies (represented in the figure within their respective superclusters), as well as many others that aren't visible (dark galaxies). The researchers used Minkowski functionals to verify the structure's overall shape and size; the first three quantifying the thickness, width, and length followed by the fourth determining the structure's overall curvature, and compared the luminosities and stellar masses within the superstructure to known high stellar mass galaxies within the SDSS's 7th data release, DR7. This allowed the team to scale the data using known values, from local superclusters, to determine the overall morphology of the BOSS Great Wall. The question is whether the supercluster complex is moving together or being slowly separated by the expanding universe. When compared to several other chain structures, such as the Sloan Great Wall, the BOSS Great Wall's superclusters are far richer, containing more dense, high stellar mass galaxies.

Caelum Supercluster
The Caelum Supercluster, also known as SCl 59, may be a massive supercluster; spanning 910 million light-years, it is perhaps the largest galaxy supercluster in the universe, has a mass of 2×1017 solar masses, 1.7 times the mass of Laniakea Supercluster and of the Horologium Supercluster, centered on coordinates right ascension 04:43:0 and declination &minus;33°30′.

Centaurus Supercluster
"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 [...]."

Coma Supercluster
"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."

The Coma Supercluster (SCl 117), a nearby supercluster that comprises the Coma Cluster (Abell 1656) and the Leo Cluster (Abell 1367) is located 300 million light-years from Earth, it is in the center of the Great Wall and a part of Coma Filament. The Coma Supercluster is the nearest massive cluster of galaxies to our own Virgo Supercluster.

Corona Borealis Supercluster
"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."

The Corona Borealis Supercluster is a supercluster located in the constellation Corona Borealis and the most prominent example of its kind in the Northern Celestial Hemisphere. Dense and compact compared with other superclusters, its mass has been calculated to lie somewhere between 0.6 and 12 × 1016 solar masses (M⊙), which contains the galaxy clusters Abell 2056, Abell 2061, Abell 2065 (the most massive galaxy cluster within the supercluster), Abell 2067, Abell 2079, Abell 2089, and Abell 2092, where Abell 2056, 2061, 2065, 2067 and A2089 are gravitationally bound and in the process of collapsing to form a massive cluster. This entity has an estimated mass of around 1 × 1016 M⊙. If there is inter-cluster mass present, then Abell 2092 may also be involved. It has been estimated to be 100 megaparsecs (330 million light-years) wide and 40 megaparsecs (130 million light years) deep, which has a redshift of 0.07, which is equivalent to a distance of around 265.5 megaparsecs (964 million light-years).

Draco Supercluster
Draco Supercluster (SCL 114) is a galaxy supercluster in the constellation Draco. It is located at a distance of 300 Mpc h-1 on a side of a void of diameter of about 130 Mpc h-1. The near side of the void is bordered by the Ursa Major supercluster. The estimated size of the supercluster reaches 410 million light years and a mass of 1017 solar mass, making it one of the largest and most massive superclusters known in the observable universe.

Giant Arc
A ""giant arc" of galaxies stretching more than 3 billion light-years across."

The guiding heuristic "expects homogeneity of matter on sections of [the] universe larger than 1.2 billion light-years across. But the Giant Arc is heterogenous on a scale three times that size."

"That means THREE of these arcs could fit between us and the edge of the observable universe-- 10 degrees on the sky, or 20 full moons!"

The "Giant Arc’s “signature” on the electromagnetic spectrum is in magnesium atoms that have lost one electron; meaning the light we receive from the quasars behind the arc is absorbed and emitted by these magnesium atoms, and thusly has a particular wavelength when we receive it on Earth."

Hercules–Corona Borealis Great Wall
Hercules–Corona Borealis Great Wall or the Great GRB Wall is a massive galactic superstructure in a region of the sky seen in the data set mapping of gamma-ray bursts (GRBs) that has been found to have an unusually higher concentration of similarly distanced GRBs than the expected average distribution. It was discovered in early November 2013 by a team of American and Hungarian astronomers led by István Horváth, Jon Hakkila and Zsolt Bagoly while analyzing data from the Swift Gamma-Ray Burst Mission, together with other data from ground-based telescopes. It is the largest known formation in the universe, exceeding the size of the prior Huge-LQG by about two times.

Hercules Supercluster
"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."

The Hercules Superclusters (SCl 160) refers to a set of two nearby superclusters of galaxies.

Horologium Supercluster
"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."

The Horologium Supercluster is a massive supercluster spanning around 550 million light-years, centered on coordinates right ascension 03:19:0 and declination &minus;50°02′, spans an angular area of 12° × 12°, and has about 5,000 galaxy groups (30,000 giant galaxies and 300,000 dwarf galaxies), and includes the galaxy cluster Abell 3266.

Hydra-Centaurus Supercluster
Within the proximity of this supercluster lies the Great Attractor, dominated by the Norma Cluster (Abell 3627), where this massive cluster of galaxies exerts a large gravitational force, causing all matter within 50 Mpc to experience a bulk flow of 600 km/s toward the Norma Cluster

Hydra Supercluster
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, [...]."

Hyperion proto-supercluster
The Hyperion proto-supercluster is the largest and earliest known proto-supercluster, 5,000 times the mass of the Milky Way and seen at 20% of the current age of the universe, discovered in 2018 by analysing the redshifts of 10,000 objects observed with the Very Large Telescope in Chile.

Laniakea Supercluster
The Laniakea Supercluster (Laniakea, Hawaiian for open skies or immense heaven; also called the Local Supercluster or 'Local SCl or sometimes Lenakaeia) is the galaxy supercluster that is home to the Milky Way and approximately 100,000 other nearby galaxies. , defined in September 2014, when a group of astronomers including R. Brent Tully of the University of Hawaii at Manoa, Hélène Courtois of the University of Lyon, Yehuda Hoffman of the Hebrew University of Jerusalem, and Daniel Pomarède of CEA Université Paris-Saclay published a new way of defining superclusters according to the relative velocities of galaxies, where the new definition of the local supercluster subsumes the prior defined local supercluster, the Virgo Supercluster, as an appendage.

Subsequent studies suggest that Laniakea is not gravitationally bound and will disperse rather than continue to maintain itself as an overdensity relative to surrounding areas.

Leo Supercluster
"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."

The Leo Supercluster, in the Northern Celestial Hemisphere stretches across the constellations Ursa Major and Leo that covers an area approximately 130 megaparsecs long by 60 megaparsecs wide, as the redshifts of member galaxy cluster]s range from 0.032 to 0.043, with the brightest cluster in the system is Abell 1185.

Local Sheet
The Local Sheet is a nearby extragalactic region of space where the Milky Way, the members of the Local Group and other galaxies share a similar peculiar velocity. This region lies within a radius of about 7 Mpc (23 Mly), 1.5 Mly thick, and galaxies beyond that distance show markedly different velocities. The Local Group has only a relatively small peculiar velocity of $66 km.s^{-1}$ with respect to the Local Sheet. Typical velocity dispersion of galaxies is only $40 km.s^{-1}$ in the radial direction. Nearly all nearby bright galaxies belong to the Local Sheet. The Local Sheet is part of the Local Volume and is in the Virgo Supercluster (Local Supercluster). The Local Sheet forms a wall of galaxies delineating one boundary of the Local Void.

A significant component of the mean velocity of the galaxies in the Local Sheet appears as the result of the gravitational attraction of the Virgo Cluster of galaxies, resulting in a peculiar motion ~$185 km.s^{-1}$ toward the cluster. A second component is directed away from the center of the Local Void; an expanding region of space spanning an estimated 45 Mpc that is only sparsely populated with galaxies. This component has a velocity of $259 km.s^{-1}$. The Local Sheet is inclined 8° from the Local Supercluster (Virgo Supercluster).

The so-called Council of Giants is a ring of twelve large galaxies surrounding the Local Group in the Local Sheet, with a radius of 3.75 Mpc. Ten of these are spiral galaxies, while the remaining two are elliptical galaxies: ellipticals (Maffei 1 and Centaurus A) lie on opposite sides of the Local Group, and their formation may have prompted the development of the Local Group, where the Local Sheet's own development outlines a concentration of dark matter in a filament.

* The mass is given as the logarithm of the mass in solar masses.

Lynx Supercluster
The Lynx Supercluster was discovered in 1999 as ClG J0848+4453, a name now used to describe the western cluster, with ClG J0849+4452 being the eastern one, containing at least two clusters, designated RXJ 0848.9+4452 (at redshift z=1.26) and RXJ 0848.6+4453 (redshift z=1.27), the most distant known supercluster with a comoving distance of 12.9 billion light years, with seven smaller groups of galaxies are associated with the supercluster. Through electromagnetic radiation and how it reacts with matter, we have been able to find three groupings of stars and two x-ray clusters within the Lynx.

Microscopium Supercluster
The Microscopium Supercluster is a supercluster located in the constellation Microscopium composed of Abell clusters 3695 and 3696 that likely are, while the relations of Abell clusters 3693 and 3705 in the same field are unclear.

MS 0302+17
MS 0302 + 17 is a galaxy supercluster located in the constellation Aries at a distance of 4.485 billion light years (lookback time), equivalent to a comoving distance of 5.338 billion light years, dimensions around 6 million parsecs.

The MS prefix derives from Medium Sensitivity because X-ray observations are part of the Einstein Medium Sensitivity Survey. An interesting fact of the survey is a couple of giant arches located near the luminous central galaxies of MS0302 + 1659, images of remote galaxies enhanced by the gravitational lensing phenomenon created by the supercluster.

Ophiuchus Supercluster
Ophiuchus Supercluster is a nearby galaxy supercluster in the constellation Ophiuchus. The supercluster forms the far wall of the Ophiuchus Void; it may also be connected in a filament, with the Pavo-Indus-Telescopium Supercluster and the Hercules Supercluster.

Pavo-Indus Supercluster
"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."

Other groups and clusters in the supercluster include the NGC 6769 Group and Abell S805 (IC 4765 Group, Pavo II, DRCG 1842-63).

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

The Perseus-Pisces Supercluster (SCl 40) borders a prominent void, the Taurus Void, and is part of the Perseus–Pegasus Filament which stretches for roughly a billion light years.

Pisces-Cetus Supercluster
"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."

The Pisces–Cetus Supercluster Complex is a galaxy filament that includes the Virgo Supercluster which in turn contains the Local Group, the galaxy cluster that includes the Milky Way.

Saraswati Supercluster
The Saraswati Supercluster is a massive galaxy supercluster about 1.2 gigaparsecs (4,000 million light years) away within the Stripe 82 region of Sloan Digital Sky Survey (SDSS), in the direction of the constellation Pisces. It is one of the largest structures found in the universe, with a major axis in diameter of about 200 Mpc (652 million light years), consisting of at least 43 galaxy clusters, and has the mass of 2 × 1016 Solar mass, forming a galaxy filament.

Sculptor Supercluster
"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."

The Sculptor Wall is a superstructure of galaxies ("wall of galaxies") relatively near to the Milky Way Galaxy (redshift of approximately z=0.03), also known as the Sculptor superclusters.

The superstructure is also called "Southern Great Wall", "Great Southern Wall", "Southern Wall", in reference to the Northern Great Wall, or just "Great Wall" &mdash; the CfA2 Great Wall, is 8000 km/s long, 5000 km/s wide, 1000 km/s deep, in redshift space dimensions.

Shapley Supercluster
"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."

The nearest large underdense area has been labelled the dipole repeller.

Vela Supercluster
The Vela Supercluster (Vela SCl, VSCL) is a massive galactic supercluster about 265.5 megaparsecs (870 million light-years) away within the vicinity of the Zone of Avoidance, centered on the constellation Velal one of the largest structures found in the universe; covering about 25 × 20 degrees of the sky, consisting of two walls: a broad main wall and a secondary merging wall, where the combined dimensions of the walls are 115 km/s Mpc on the major dimensions and 90 km/s Mpc on the minor ones, which corresponds to about 385 million and 300 million light years, respectively, about "1 000 times the mass of the Milky Way galaxy", which corresponds to a mass of 1 × 1015 solar masses, about 20 initial galaxy clusters have been identified spectroscopically.

Virgo Supercluster
Def. a "supercluster that includes the Milky Way galaxy" is called the Virgo Supercluster.

Rings
Circular "patterns of galaxies [are] scattered across the sky".

Local Superclusters
Def. a "supercluster which includes the Milky Way galaxy" is called a Local Supercluster.