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List Of Voids
This is a list of voids in astronomy. Voids are particularly galaxy-poor regions of space between filaments, making up the large-scale structure of the universe. Some voids are known as ''supervoids''. In the tables, ''z'' is the cosmological redshift, ''c'' the speed of light, and ''h'' the dimensionless Hubble parameter, which has a value of approximately 0.7 (the Hubble constant ''H''0 = ''h'' × 100 km s−1 Mpc−1). Mpc stands for megaparsec. The co-ordinates (right ascension and declination) and distance given refer to the approximate center of the region. Voids and supervoids Largest voids Named voids SIMBAD"list of objects in '*void' wildcard search"(accessed 15 September 2009)SIMBAD"list of objects of type 'vid'"(accessed 15 September 2009) Voids designated by their constellation Other voids Voids by search or survey Tully list In 1985, Tully determined a local dominant supercluster plane, and found the Pisces–Cetus Superclust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Void (astronomy)
Cosmic voids (also known as dark space) are vast spaces between filaments (the largest-scale structures in the universe), which contain very few or no galaxies. 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 for an observer. Voids typically have a diameter of 10 to 100 megaparsecs (30 to 300 million light-years); particularly large voids, defined by the absence of rich superclusters, are sometimes called supervoids. They were first discovered in 1978 in a pioneering study by Stephen Gregory and Laird A. Thompson at the Kitt Peak National Observatory. Voids are believed to have been formed by baryon acoustic oscillations in the Big Bang, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sculptor Supercluster
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.Taotao Fang, David A. Buote, Philip J. Humphrey, Claude R. Canizares, Luca Zappacosta, Roberto Maiolino, Gianpiero Tagliaferri and Fabio Gastaldello; ''CONFIRMATION OF X-RAY ABSORPTION BY WARM-HOT INTERGALACTIC MEDIUM IN THE SCULPTOR WALL''; 2010 ApJ 714 1715, , , /ref>Fairall, A. P., Palumbo, G. G. C., Vettolani, G., Kauffman, G., Jones, A., & Baiesi-Pillastrini, G., ''Largescale Structure in the Universe - Plots from the Updated Catalogue of Radial Velocities of Galaxies and the Southern Redshift Catalogue'' Journal: R.A.S. MONTHLY NOTICES V.247, NO.2/NOV15, P. 23P, 1990. Bibliographic Code:(slices 8 and 10 under SGH) The superstructure is also called the Southern Great Wall, the Great Southern Wall, or just the Southern Wall, in reference to the CfA2 Great Wall, Northern Great Wall. The str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 one lobe, and the Andromeda Galaxy and its satellites constitute the other. The two collections are separated by about and are moving toward one another with a velocity of . The group itself is a part of the larger Virgo Supercluster, which may be a part of the Laniakea Supercluster. The exact number of galaxies in the Local Group is unknown as some are occluded by the Milky Way; however, at least 80 members are known, most of which are dwarf galaxies. The two largest members, the Andromeda Galaxy and the Milky Way, are both spiral galaxies with masses of about solar masses each. Each has its own system of satellite galaxies: * The Andromeda Galaxy's satellite system consists of Messier 32 (M32), Messier 110 (M110), NGC 147, NGC 185, A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milky Way
The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. The term ''Milky Way'' is a translation of the Latin ', from the Greek ('), meaning "milky circle". From Earth, the Milky Way appears as a band because its disk-shaped structure is viewed from within. Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies. The Milky Way is a barred spiral galaxy with an estimated D25 isophotal diameter of , but only about 1,000 light years thick at the spiral arms (more at the bulg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KBC Void
The KBC Void (or Local Hole) is an immense, comparatively empty region of space, named after astronomers Ryan Keenan, Amy Barger, and Lennox Cowie, who studied it in 2013. The existence of a local underdensity has been the subject of many pieces of literature and research articles. The underdensity is proposed to be roughly spherical, approximately 2 billion light-years (600 megaparsecs, Mpc) in diameter. As with other voids, it is not completely empty but contains the Milky Way, the Local Group, and the larger part of the Laniakea Supercluster. The Milky Way is within a few hundred million light-years of the void's center. It is debated whether the existence of the KBC void is consistent with the ΛCDM model. While Haslbauer et al. say that voids as large as the KBC void are inconsistent with ΛCDM, Sahlén et al. argue that the existence of supervoids such as the KBC void is consistent with ΛCDM. Galaxies inside a void experience a gravitational pull from outside the void, whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomy & Astrophysics
''Astronomy & Astrophysics'' is a monthly peer-reviewed scientific journal covering theoretical, observational, and instrumental astronomy and astrophysics. The journal is run by a Board of Directors representing 27 sponsoring countries plus a representative of the European Southern Observatory. The journal is published by EDP Sciences and the editor-in-chief is . History Origins ''Astronomy and Astrophysics'' (A&A) was created as an answer to the publishing scenario found in Europe in the 1960s. At that time, multiple journals were being published in several countries around the continent. These journals usually had a limited number of subscribers, and published articles in languages other than English, resulting in a small number of citations compared to American and British journals. Starting in 1963, conversations between astronomers from European countries assessed the need for a common astronomical journal. On 8 April 1968, leading astronomers from Belgium, Denmark, Franc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giant Void
The Giant Void (also known as the Giant Void in NGH, Canes Venatici Supervoid, and AR-Lp 36) is an extremely large region of space with an underdensity of galaxies and located in the constellation Canes Venatici. It is the second-largest-confirmed void to date, with an estimated diameter of 300 to 400 Mpc (1 to 1.3 billion light-years) and its centre is approximately 1.5 billion light-years away ( z = 0.116). It was discovered in 1988,"The Northern Cone of Metagalaxy" (Kopylov et al. 1988) and was the largest void in the Northern Galactic Hemisphere, and possibly the second-largest ever detected. Even the hypothesized "Eridanus Supervoid" corresponding to the location of the WMAP cold spot is dwarfed by this void, although the Giant Void does not correspond to any significant cooling to the cosmic microwave background. Inside this vast void there are 17 galaxy clusters, concentrated in a spherically shaped region 50 Mpc in diameter. Studies of the motion of these clusters show ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southern Local Supervoid
The Southern Local Supervoid is a tremendously large, nearly empty region of space (a void). It lies next to the Local Supercluster, which contains our galaxy the Milky Way. Its center is 96 megaparsecs away and the void is 112 megaparsecs in diameter across its narrowest width. Its volume is very approximately 600 billion times that of the Milky Way. See volumes of similar orders of magnitude. See also * List of largest voids * KBC Void The KBC Void (or Local Hole) is an immense, comparatively empty region of space, named after astronomers Ryan Keenan, Amy Barger, and Lennox Cowie, who studied it in 2013. The existence of a local underdensity has been the subject of many pieces o ... References Voids (astronomy) {{galaxy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pegasus Void
Pegasus ( grc-gre, Πήγασος, Pḗgasos; la, Pegasus, Pegasos) is one of the best known creatures in Greek mythology. He is a winged divine stallion usually depicted as pure white in color. He was sired by Poseidon, in his role as horse-god, and foaled by the Gorgon Medusa. He was the brother of Chrysaor, born at a single birthing when his mother was decapitated by Perseus. Greco-Roman poets wrote about his ascent to heaven after his birth and his obeisance to Zeus, king of the gods, who instructed him to bring lightning and thunder from Olympus. Pegasus is the creator of Hippocrene, the fountain on Mount Helicon. He was captured by the Greek hero Bellerophon, near the fountain Peirene, with the help of Athena and Poseidon. Pegasus allowed Bellerophon to ride him in order to defeat the monster Chimera, which led to many more exploits. Bellerophon later fell from Pegasus's back while trying to reach Mount Olympus. Both Pegasus and Bellerophon were said to have die ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southern Local Void
The Southern Local Supervoid is a tremendously large, nearly empty region of space (a void). It lies next to the Local Supercluster, which contains our galaxy the Milky Way. Its center is 96 megaparsecs away and the void is 112 megaparsecs in diameter across its narrowest width. Its volume is very approximately 600 billion times that of the Milky Way. See volumes of similar orders of magnitude. See also * List of largest voids * KBC Void The KBC Void (or Local Hole) is an immense, comparatively empty region of space, named after astronomers Ryan Keenan, Amy Barger, and Lennox Cowie, who studied it in 2013. The existence of a local underdensity has been the subject of many pieces o ... References Voids (astronomy) {{galaxy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pegasus Supercluster
Pegasus ( grc-gre, Πήγασος, Pḗgasos; la, Pegasus, Pegasos) is one of the best known creatures in Greek mythology. He is a winged divine stallion usually depicted as pure white in color. He was sired by Poseidon, in his role as horse-god, and foaled by the Gorgon Medusa. He was the brother of Chrysaor, born at a single birthing when his mother was decapitated by Perseus. Greco-Roman poets wrote about his ascent to heaven after his birth and his obeisance to Zeus, king of the gods, who instructed him to bring lightning and thunder from Olympus. Pegasus is the creator of Hippocrene, the fountain on Mount Helicon. He was captured by the Greek hero Bellerophon, near the fountain Peirene, with the help of Athena and Poseidon. Pegasus allowed Bellerophon to ride him in order to defeat the monster Chimera, which led to many more exploits. Bellerophon later fell from Pegasus's back while trying to reach Mount Olympus. Both Pegasus and Bellerophon were said to have die ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boötes Void
Boötes ( ) is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from la, Boōtēs, which comes from grc-gre, Βοώτης, Boṓtēs ' herdsman' or 'plowman' (literally, ' ox-driver'; from ''boûs'' 'cow'). One of the 48 constellations described by the 2nd-century astronomer Ptolemy, Boötes is now one of the 88 modern constellations. It contains the fourth-brightest star in the night sky, the orange giant Arcturus. Epsilon Boötis, or Izar, is a colourful multiple star popular with amateur astronomers. Boötes is home to many other bright stars, including eight above the fourth magnitude and an additional 21 above the fifth magnitude, making a total of 29 stars easily visible to the naked eye. History and mythology In ancient Babylon, the stars of Boötes were known as SHU.PA. They were apparently depicted as the god Enlil, who was the leader of the Babylonian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
