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List Of Spiral DRAGNs
Spiral DRAGNs are a type of galaxy; spiral galaxies which contain DRAGNs (Double Radio-source Associated with Galactic Nucleus), and are therefore also radio galaxies. Most DRAGNs are associated with elliptical galaxies, as are most double-lobed radio-galaxies. Spiral DRAGNs are inconsistent with currently known galaxy formation processes. As of 2016, there are 6 known spiral DRAGNs that are widely accepted. Lenticlular galaxies containing DRAGNs are as rare as spiral DRAGNs, with only 5 known examples as of 2020, including: Centaurus A, NGC 612 and NGC 1534 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 * Nati .... List Notes References {{DEFAULTSORT:Spiral DRAGNs Radio galaxies *Spiral DRAGN list Lists of galaxies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy
A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. Galaxies, averaging an estimated 100 million stars, range in size from dwarfs with less than a hundred million stars, to the largest galaxies known – supergiants with one hundred trillion stars, each orbiting its galaxy's center of mass. Most of the mass in a typical galaxy is in the form of dark matter, with only a few percent of that mass visible in the form of stars and nebulae. Supermassive black holes are a common feature at the centres of galaxies. Galaxies are categorized according to their visual morphology as elliptical, spiral, or irregular. Many are thought to have supermassive black holes at their centers. The Milky Way's central black hole, known as Sagittarius A*, has a mass four million times greater than the Sun. As o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Very-long-baseline Interferometry
Very-long-baseline interferometry (VLBI) is a type of astronomical interferometer, astronomical interferometry used in radio astronomy. In VLBI a signal from an astronomical radio source, such as a quasar, is collected at multiple radio telescopes on Earth or in space. The distance between the radio telescopes is then calculated using the time difference between the arrivals of the radio signal at different telescopes. This allows observations of an object that are made simultaneously by many radio telescopes to be combined, emulating a telescope with a size equal to the maximum separation between the telescopes. Data received at each antenna in the array include arrival times from a local atomic clock, such as a hydrogen maser. At a later time, the data are correlated with data from other antennas that recorded the same radio signal, to produce the resulting image. The resolution achievable using interferometry is proportional to the observing frequency. The VLBI technique e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Galaxies
A radio galaxy is a galaxy with giant regions of radio emission extending well beyond its visible structure. These energetic radio lobes are powered by jets from its active galactic nucleus. They have luminosities up to 1039 W at radio wavelengths between 10 MHz and 100 GHz. The radio emission is due to the synchrotron process. The observed structure in radio emission is determined by the interaction between twin jets and the external medium, modified by the effects of relativistic beaming. The host galaxies are almost exclusively large elliptical galaxies. ''Radio-loud'' active galaxies can be detected at large distances, making them valuable tools for observational cosmology. Recently, much work has been done on the effects of these objects on the intergalactic medium, particularly in galaxy groups and clusters. Alcyoneus is a low-excitation radio galaxy, identified as having the largest radio lobes found, with lobed structures spanning 5 megaparsecs (16×10 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irregular Galaxy
An irregular galaxy is a galaxy that does not have a distinct regular shape, unlike a spiral or an elliptical galaxy. Irregular galaxies do not fall into any of the regular classes of the Hubble sequence, and they are often chaotic in appearance, with neither a nuclear bulge nor any trace of spiral arm structure. Collectively they are thought to make up about a quarter of all galaxies. Some irregular galaxies were once spiral or elliptical galaxies but were deformed by an uneven external gravitational force. Irregular galaxies may contain abundant amounts of gas and dust. This is not necessarily true for dwarf irregulars. Irregular galaxies are commonly small, about one tenth the mass of the Milky Way galaxy. Due to their small sizes, they are prone to environmental effects like crashing with large galaxies and intergalactic clouds. Types There are three major types of irregular galaxies: * An Irr-I galaxy (Irr I) is an irregular galaxy that features some structure but not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy Merger
Galaxy mergers can occur when two (or more) galaxies collide. They are the most violent type of galaxy interaction. The gravitational interactions between galaxies and the friction between the gas and dust have major effects on the galaxies involved. The exact effects of such mergers depend on a wide variety of parameters such as collision angles, speeds, and relative size/composition, and are currently an extremely active area of research. Galaxy mergers are important because the merger rate is a fundamental measurement of galaxy evolution. The merger rate also provides astronomers with clues about how galaxies bulked up over time. Description During the merger, stars and dark matter in each galaxy become affected by the approaching galaxy. Toward the late stages of the merger, the gravitational potential (i.e. the shape of the galaxy) begins changing so quickly that star orbits are greatly altered, and lose any trace of their prior orbit. This process is called “violent r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy Zoo
Galaxy Zoo is a crowdsourced astronomy project which invites people to assist in the morphological classification of large numbers of galaxies. It is an example of citizen science as it enlists the help of members of the public to help in scientific research. There have been 15 versions as of July 2017. Galaxy Zoo is part of the Zooniverse, a group of citizen science projects. An outcome of the project is to better determine the different aspects of objects and to separate them into classifications. Origins A key factor leading to the creation of the project was the problem of what has been referred to as data deluge, where research produces vast sets of information to the extent that research teams are not able to analyse and process much of it. Kevin Schawinski, previously an astrophysicist at Oxford University and co-founder of Galaxy Zoo, described the problem that led to Galaxy Zoo's creation when he was set the task of classifying the morphology of more than 900,000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grand Design Spiral Galaxy
A grand design spiral galaxy is a type of spiral galaxy with prominent and well-defined spiral arms, as opposed to multi-arm and flocculent spirals which have subtler structural features. The spiral arms of a grand design galaxy extend clearly around the galaxy through many radians and can be observed over a large fraction of the galaxy's radius. As of 2002, approximately 10 percent of all currently known spiral galaxies are classified as grand design type spirals, including M51, M74, M81, M83, and M101. Origin of structure Density wave theory is the preferred explanation for the well-defined structure of grand design spirals, first suggested by Lin and Shu in 1964. The term "grand design" was not used in this work, but appeared in the 1966 continuation paper, Lin (along with Yuan and Shu) is usually credited with coining of the term. According to the density wave theory, the spiral arms are created inside density waves that turn around the galaxy at different speeds fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SDSS J1649+2635
SDSS may refer to: * Sloan Digital Sky Survey, a major multi-filter imaging and spectroscopic redshift survey * Social Democratic Party of Slovakia * Spatial Decision Support System, a GIS based decision aiding system * Independent Democratic Serb Party The Independent Democratic Serb Party ( sh-Cyrl-Latn, Самостална демократска српска странка, Samostalna demokratska srpska stranka, SDSS) is a social-democratic political party in Croatia representing the interes ..., a political party of Croatian Serbs (''Samostalna demokratska srpska stranka'' in Serbo-Croatian) * South Delta Secondary School, a school in Delta, British Columbia, Canada {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abell 428
{{disambiguation, geo ...
Abell may refer to: People *Abell (surname) *George O. Abell, of the astronomical catalogues fame Places ;United States * Abell, Maryland, a location in St. Mary's County, Maryland * Abell, a neighborhood in Baltimore, Maryland * Abells Corners, Wisconsin, an unincorporated community Astronomy *Abell catalogue of rich clusters of galaxies (ACO) *Abell Catalog of Planetary Nebulae (A) Bibliographical database *ABELL, the ''Annual Bibliography of English Language and Literature'' See also *Abel (other) Abel was a son of Adam and Eve in the Bible. According to the Bible, he was the first person to die, murdered by his brother Cain. Abel may also refer to: People and fictional characters * Abel (given name), including a list of people and ficti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiral Galaxies
Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''Alt URL pp. 124–151) and, as such, form part of the . Most spiral galaxies consist of a flat, rotating containing s, gas and dust, and a central concentration of stars known as the |
NGC 1534
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 orga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
