The Great Attractor is a region of gravitational attraction in intergalactic space and the apparent central gravitational point of the Laniakea Supercluster of galaxies that includes the Milky Way galaxy, as well as about 100,000 other galaxies.
The Hydra–Centaurus Supercluster, or the Hydra and Centaurus Superclusters, was a previously defined supercluster in two parts, which prior to the identification of Laniakea Supercluster in 2014 is the closest neighbour of the former Virgo Supercluster. Its center is located about 39 Mpc (127 Mly) away, with it extending to a maximum distance of around 69 Mpc (225 Mly).
The Pavo–Indus Supercluster is a neighboring supercluster located about 60–70 Mpc (196–228 Mly) away in the constellations of Pavo, Indus, and Telescopium. The supercluster contains three main clusters, Abell 3656, Abell 3698, and Abell 3742.
In cosmology, galaxy filaments are the largest known structures in the universe, consisting of walls of galactic superclusters. These massive, thread-like formations can commonly reach 50/h to 80/h megaparsecs —with the largest found to date being the Hercules-Corona Borealis Great Wall at around 3 gigaparsecs (9.8 Gly) in length—and form the boundaries between voids. Due to the accelerating expansion of the universe, the individual clusters of gravitationally bound galaxies that make up galaxy filaments are moving away from each other at an accelerated rate; in the far future they will dissolve.
The thick disk is one of the structural components of about 2/3 of all disk galaxies, including the Milky Way. It was discovered first in external edge-on galaxies. Soon after, it was proposed as a distinct galactic structure in the Milky Way, different from the thin disk and the halo in the 1983 article by Gilmore & Reid. It is supposed to dominate the stellar number density between 1 and 5 kiloparsecs above the galactic plane and, in the solar neighborhood, is composed almost exclusively of older stars. Its stellar chemistry and stellar kinematics are also said to set it apart from the thin disk. Compared to the thin disk, thick disk stars typically have significantly lower levels of metals—that is, the abundance of elements other than hydrogen and helium.
NGC 3783 is a barred spiral galaxy located about 135 million light years away in the constellation Centaurus. It is inclined by an angle of 23° to the line of sight from the Earth along a position angle of about 163°. The morphological classification of SBa indicates a bar structure across the center (B) and tightly-wound spiral arms (a). Although not shown by this classification, observers note the galaxy has a luminous inner ring surrounding the bar structure. The bright compact nucleus is active and categorized as a Seyfert 1 type. This nucleus is a strong source of X-ray emission and undergoes variations in emission across the electromagnetic spectrum.
U1.11 is a large quasar group located in the constellations of Leo and Virgo. It is one of the largest LQG's known, with the estimated maximum diameter of 780 Mpc and contains 38 quasars. It was discovered in 2011 during the course of the Sloan Digital Sky Survey. Until the discovery of the Huge-LQG in November 2012, it was the largest known structure in the universe, beating Clowes–Campusano LQG's 20-year record as largest known structure at the time of its discovery.
Cosmic voids are vast spaces between filaments, which contain very few or no galaxies. In spite of their size, most galaxies are not located in voids. This is because most galaxies are gravitationally bound together, creating huge cosmic structures known as galaxy filaments. The cosmological evolution of the void regions differs drastically from the evolution of the Universe as a whole: there is a long stage when the curvature term dominates, which prevents the formation of galaxy clusters and massive galaxies. Hence, although even the emptiest regions of voids contain more than ~15% of the average matter density of the Universe, the voids look almost empty to an observer.
The Southern Supercluster is a nearby supercluster located around 19.5 Mpc (63.6 Mly) in the constellations of Cetus, Fornax, Eridanus, Horologium, and Dorado. It was first identified in 1953 by Gérard de Vaucouleurs.
NGC 4709 is an elliptical galaxy located in the constellation Centaurus. It is considered to be a member of the Centaurus Cluster and is the dominant member of a small group of galaxies known as "Cen 45" which is currently merging with the main Centaurus Cluster even though the two subclusters' line of sight redshift velocities differ by about 1500 km/s. NGC 4709 was discovered by astronomer James Dunlop on May 7, 1826.
The Grus Wall is a superstructure of galaxies formed in the early universe, named for the Grus constellation in which it is found. It has an average redshift of z=2.38 and lies about 10.8 billion light-years away. The Wall is around 300 million light-years long, comparable in size to the Sloan Great Wall. The Wall is "perpendicular" to the Fornax Wall and Sculptor Wall.
The Fornax Wall is a superstructure known as a galaxy filament or galaxy wall. It is a long filament of galaxies with a major axis longer than its minor one. The filament contains not only Dorado Group but also the Fornax cluster of galaxies, which lies at the same distance. It is "parallel" to the Sculptor Wall and "perpendicular" to the Grus Wall.
NGC 753 is a spiral galaxy located 220 million light-years away in the constellation Andromeda. The galaxy was discovered by astronomer by Heinrich d'Arrest on September 16, 1865 and is a member of Abell 262.
The NGC 4065 Group is a group of galaxies located about 330 Mly (100 Mpc) in the constellation Coma Berenices. The group's brightest member is NGC 4065 and located in the Coma Supercluster.
NGC 4333 is a barred spiral galaxy with a ring structure located about 330 million light-years away in the constellation Virgo. It was discovered by astronomer William Herschel on April 13, 1784, who described it as "F, pS, R, bM, 2nd of 3". NGC 4333 is also classified as a LINER galaxy. Despite being listed in the Virgo Cluster catalog as VCC 637, it is not a member of the Virgo Cluster but instead a background galaxy.
The Southern Supercluster Strand is a galaxy filament that incompasses the Southern Supercluster and the Telescopium−Grus Cloud.
J2345-0449 or 2MASX J23453268-0449256, is a spiral galaxy located 947 million light-years in the constellation of Aquarius. It contains an active galactic nucleus and is classified as a radio galaxy, containing relativistic jets that are projected out from its spiral host by ~1.6 Mpc, making these jets the largest and rarest known. It was discovered in 2014 by amateur astronomers, making it the third spiral DRAGN after ESO 0313-192 and Speca.
MRC 0316-257 is a radio galaxy located in the constellation Fornax. Its redshift is 3.13, making the object located roughly 11 billion light-years from Earth.
NGC 4329 is an elliptical galaxy located 144 million light-years away in the constellation Corvus. The galaxy was discovered by astronomer John Herschel on March 9, 1828. NGC 4329 is host a supermassive black hole with an estimated mass of 3.1×108 solar masses. NGC 4329 is a member of a group of 5 galaxies known as [T2015] nest 100478. NGC 4329 is the brightest member of this group and the group includes the galaxies IC 785, IC 786, MCG-02-32-006, and LEDA 170189. The redshift of NGC 4329 places it in the within the bounds of the Hydra-Centaurus supercluster.
