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Dorado Group
The Dorado Group is a loose concentration of galaxies containing both spirals and ellipticals. It is generally considered a 'galaxy group' but may approach the size of a 'galaxy cluster'. It lies primarily in the southern constellation Dorado and is one of the richest galaxy groups of the Southern Hemisphere. Gérard de Vaucouleurs was the first to identify it in 1975 as a large complex nebulae II in the Dorado region, designating it as G16. Characteristics A rough distance estimate from NGC 1549 (using the Hubble constant as 70) put the cluster at 18.4 megaparsecs (Mpc). The Cepheid distance estimate from Freedman et al. 2001 is 15.3 Mpc. Based upon the 2001 work of Tonry et al. the surface brightness fluctuation (SBF) of six member galaxies was averaged and adjusted to estimate the group's distance at in 2007. At the center of the cluster lie interacting galaxies NGC 1549 and NGC 1553. The dominant group members, ordered by luminosity, are: spiral NGC 1566, lenticular N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sig05-013 Small
Sig used as a name may refer to: *Sig (given name) *Sig, Algeria, a city on the banks of the Sig River *Sig Alert, an alert for traffic congestion in California, named after Loyd Sigmon *Sig River, a river of Algeria also known as Mekerra sig (lower case) may refer to: *sig (rune), an Armanen rune, later used for the Schutzstaffel (SS) logo *sig, the distinctive hand actions of sign language that form words; see movement (sign language) * .sig, a signature block in e-mail messaging ''sig'' as a loanword may refer to: *''sig'' (Russian), the common whitefish; see ''Coregonus'' *''Sig'' (Italian), abbreviation of ''Signore'' ("Lord") *''Sig.'' (Latin, also ''Signa'' or ''Signatura''), the "signature" section of a medical prescription, which contains directions to the patient, and the signature of the prescribing doctor *Sig. Signaling ( in R''ail transport'') the signals and associated equipment required for their operation. SIG (capitalized) may refer to: *SIG, the IATA Callsign o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 1553
NGC 1553 is a prototypical lenticular galaxy in the constellation Dorado. It is the second brightest member of the Dorado Group of galaxies. British astronomer John Herschel discovered NGC 1553 on December 5, 1834 using an 18.7 inch reflector. Interacting galaxy It forms a pair of interacting galaxies together with elliptical NGC 1549 which lies 11′.8 away from it in the sky. Their interaction appears to be in the early stage and can be seen in optical wavelengths by faint but distinct irregular shells of emission and a curious jet on the northwest side. Together, these two galaxies comprise the center of the Dorado group. Characteristics NGC 1553 is an early type galaxy with a luminosity of 4 ''L''⊙. It has been detected in H I but has an H I mass to B-band luminosity ratio (''M''HI/''L''B) of less than 0.01. NGC 1553's ultraviolet spectrum shows weak flux under the main-sequence turn off at around 2,400 A°. This is characteristic of old intermediate populat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Age Of The Universe
In physical cosmology, the age of the universe is the time elapsed since the Big Bang. Astronomers have derived two different measurements of the age of the universe: a measurement based on direct observations of an early state of the universe, which indicate an age of billion years as interpreted with the Lambda-CDM concordance model as of 2018; and a measurement based on the observations of the local, modern universe, which suggest a younger age. The uncertainty of the first kind of measurement has been narrowed down to 20 million years, based on a number of studies which all show similar figures for the age and which include studies of the microwave background radiation by the ''Planck'' spacecraft, the Wilkinson Microwave Anisotropy Probe and other space probes. Measurements of the cosmic background radiation give the cooling time of the universe since the Big Bang, and measurements of the expansion rate of the universe can be used to calculate its approxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy Morphological Classification
Galaxy morphological classification is a system used by astronomers to divide galaxies into groups based on their visual appearance. There are several schemes in use by which galaxies can be classified according to their morphologies, the most famous being the Hubble sequence, devised by Edwin Hubble and later expanded by Gérard de Vaucouleurs and Allan Sandage. However, galaxy classification and morphology are now largely done using computational methods and physical morphology. Hubble sequence The Hubble sequence is a morphological classification scheme for galaxies invented by Edwin Hubble in 1926. It is often known colloquially as the “Hubble tuning-fork” because of the shape in which it is traditionally represented. Hubble's scheme divides galaxies into three broad classes based on their visual appearance (originally on photographic plates): * Elliptical galaxies have smooth, featureless light distributions and appear as ellipses in images. They are denoted by the l ... [...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] |
Fornax Cluster
The Fornax Cluster is a cluster of galaxies lying at a distance of 19 megaparsecs (62 million light-years). It has an estimated mass of solar masses, making it the second richest galaxy cluster within 100 million light-years, after the considerably larger Virgo Cluster. It may be associated with the nearby Eridanus Group. It lies primarily in the constellation Fornax, with its southern boundaries partially crossing into the constellation of Eridanus, and covers an area of sky about 6° across or about 28 sq degrees. The Fornax Cluster is a particularly valuable source of information about the evolution of such clusters due to its relatively close proximity to the Sun. It also shows the gravitational effects of a merger of a galaxy subgroup with the main galaxy group, which in turn lends clues about the associated galactic superstructure. At the centre of the cluster lies NGC 1399. Other cluster members include NGC 1316 (the group's brightest galaxy), NGC 1365, NGC 1427A, N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bärbel Koribalski
Dr. Bärbel Silvia Koribalski is a research scientist working on galaxy formation at CSIRO's Australia Telescope National Facility (ATNF), part of CSIRO's Astronomy & Space Science (CASS). She obtained her PhD at the University of Bonn in Germany and is noted for studies of nearby galaxies. In 2011 she received CSIRO's Newton Turner Award. She is also a project leader of the ASKAP HI All-Sky Survey, known as WALLABY. Research Galaxy formation and evolution. Gas kinematics of galaxies using the HI 21-cm spectral line of neutral hydrogen. Radio observations with the Australia Telescope Compact Array (ATCA), also known as the Paul Wild Observatory in Narrabri, named after John Paul Wild, Chief of CSIRO's Division of Radiophysics and later Chairman of CSIRO (1978-1985). Study of galaxy groups, e.g. Dorado Group with V.A. Kilborn et al. Current and planned major HI surveys of galaxies: * "HI Parkes All Sky Survey" (HIPASS) * "Local Volume HI Survey" (LVHIS), conducted with th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fornax 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 The Fornax Cluster is a cluster of galaxies lying at a distance of 19 megaparsecs (62 million light-years). It has an estimated mass of solar masses, making it the second richest galaxy cluster within 100 million light-years, after the consider ... of galaxies, which lies at the same distance. It is "parallel" to the Sculptor Wall and "perpendicular" to the Grus Wall. References {{galaxy-stub Galaxy filaments Southern Supercluster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H I Region
An HI region or H I region (read ''H one'') is a cloud in the interstellar medium composed of neutral atomic hydrogen (HI), in addition to the local abundance of helium and other elements. (H is the chemical symbol for hydrogen, and "I" is the Roman numeral. It is customary in astronomy to use the Roman numeral I for neutral atoms, II for singly-ionised—HII is H+ in other sciences—III for doubly-ionised, e.g. OIII is O++, etc.) These regions do not emit detectable visible light (except in spectral lines from elements other than hydrogen) but are observed by the 21-cm (1,420 MHz) region spectral line. This line has a very low transition probability, so it requires large amounts of hydrogen gas for it to be seen. At ionization fronts, where HI regions collide with expanding ionized gas (such as an H II region), the latter glows brighter than it otherwise would. The degree of ionization in an HI region is very small at around 10−4 (i.e. one particle in 10,000). At typical inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 1433 Group
NGC commonly refers to: * New General Catalogue of Nebulae and Clusters of Stars, a catalogue of deep sky objects in astronomy NGC may also refer to: Companies * NGC Corporation, name of US electric company Dynegy, Inc. from 1995 to 1998 * National Gas Company of Trinidad and Tobago, state-owned natural gas company in Trinidad and Tobago * National Grid plc, a former name of National Grid Electricity Transmission plc, the operator of the British electricity transmission system * Northrop Grumman Corporation, aerospace and defense conglomerate formed from the merger of Northrop Corporation and Grumman Corporation in 1994 * Numismatic Guaranty Corporation, coin certification company in the United States Other uses * National Gallery of Canada, art gallery founded in 1880 in Ottawa, Canada * National Geographic, documentary and reality television channel established in the United States in 2001 formerly called National Geographic Channel * Native Girls Code, US non-profit organisat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 1566 Group
The Dorado Group is a loose concentration of galaxies containing both spirals and ellipticals. It is generally considered a 'galaxy group' but may approach the size of a 'galaxy cluster'. It lies primarily in the southern constellation Dorado and is one of the richest galaxy groups of the Southern Hemisphere. Gérard de Vaucouleurs was the first to identify it in 1975 as a large complex nebulae II in the Dorado region, designating it as G16. Characteristics A rough distance estimate from NGC 1549 (using the Hubble constant as 70) put the cluster at 18.4 megaparsecs (Mpc). The Cepheid distance estimate from Freedman et al. 2001 is 15.3 Mpc. Based upon the 2001 work of Tonry et al. the surface brightness fluctuation (SBF) of six member galaxies was averaged and adjusted to estimate the group's distance at in 2007. At the center of the cluster lie interacting galaxies NGC 1549 and NGC 1553. The dominant group members, ordered by luminosity, are: spiral NGC 1566, lenticular NG ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 1672 Group
NGC commonly refers to: * New General Catalogue of Nebulae and Clusters of Stars, a catalogue of deep sky objects in astronomy NGC may also refer to: Companies * NGC Corporation, name of US electric company Dynegy, Inc. from 1995 to 1998 * National Gas Company of Trinidad and Tobago, state-owned natural gas company in Trinidad and Tobago * National Grid plc, a former name of National Grid Electricity Transmission plc, the operator of the British electricity transmission system * Northrop Grumman Corporation, aerospace and defense conglomerate formed from the merger of Northrop Corporation and Grumman Corporation in 1994 * Numismatic Guaranty Corporation, coin certification company in the United States Other uses * National Gallery of Canada, art gallery founded in 1880 in Ottawa, Canada * National Geographic, documentary and reality television channel established in the United States in 2001 formerly called National Geographic Channel * Native Girls Code, US non-profit organisat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
