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Speca
Speca, discovered in 2011, is an exotic radio galaxy or a galaxy where the central supermassive black hole is actively accreting matter surrounding itself and ejects two giant, million light year long, plasma lobes in opposite directions.Speca is located around 1.9 billion light-years away in the constellation Virgo. Discovery and significance Speca was discovered by an international team of astronomers led by Dr Ananda Hota, using archival data from Sloan Digital Sky Survey (SDSS), Very Large Array and observations from the Giant Meterwave Radio Telescope. Where almost all radio galaxies are hosted by massive, featureless, elliptical galaxies, Speca is the first confirmed exception that such giant plasma lobes can also be hosted by spiral galaxies. This confirmation came after 12 long years of the first suspected case ESO 0313-192. Speca was a convincing case because it has two, and possibly three, episodes of such plasma lobe emission and rotation of the spiral galaxy, fas ... [...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 watt, W at radio waves, radio wavelengths between 10 MHz and 100 GHz. The radio emission is due to the synchrotron radiation, synchrotron process. The observed structure in radio emission is determined by the interaction between twin relativistic jet, jets and the external medium, modified by the effects of relativistic beaming. The host galaxy, host galaxies are almost exclusively large elliptical galaxy, 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. The term "radio galaxy" is often used to refer to the entire j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Spiral DRAGNs
Spiral DRAGNs or ''Speca-like galaxies'' are a type of spiral galaxies which are also radio galaxies or which contain DRAGNs (Double Radio-source Associated with Galactic Nucleus). 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 2024, there are nearly 36 spiral DRAGNs. Lenticlular galaxies containing DRAGNs are as rare as spiral DRAGNs, with only 5 known examples as of 2020, including: Centaurus A Centaurus A (also known as NGC 5128 or Caldwell 77) is a galaxy in the constellation of Centaurus. It was discovered in 1826 by Scottish astronomer James Dunlop from his home in Parramatta, in New South Wales, Australia. There is considerable ..., NGC 612 and NGC 1534. Nearby Seyfert galaxies containing small or galaxy-scale radio jets/lobes are not accepted as Specas or Spiral DRANGs. List Notes References {{DEFAULTSORT:Spiral DRAGNs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Galaxy
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. The term "radio galaxy" is often used to refer to the entire jet system, rather than solely to its host galaxy. Some scientists consider the term " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giant Metrewave Radio Telescope
The Giant Metrewave Radio Telescope (GMRT), located near Narayangaon, Pune in India, is an array of thirty fully steerable parabolic radio telescopes of 45 metre diameter, observing at metre wavelengths. It is the largest and most sensitive radio telescope array in the world at low frequencies. It is operated by the National Centre for Radio Astrophysics (NCRA), a part of the Tata Institute of Fundamental Research, Mumbai. It was conceived and built under the direction of Govind Swarup during 1984 to 1996. It is an interferometric array with baselines of up to . It was recently upgraded with new receivers, after which it is also known as the upgraded Giant Metrewave Radio Telescope (uGMRT). Location The Giant Metrewave Radio Telescope (GMRT) Observatory is located about 80 km north of Pune at Khodad. A nearby town is Narayangaon which is around 9 km from the telescope site. The office of National Centre for Radio Astrophysics (NCRA) is located in the Savitribai Phul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Square Kilometre Array Observatory
The Square Kilometre Array (SKA) is an intergovernmental international radio telescope project being built in Australia (low-frequency) and South Africa (mid-frequency). The combining infrastructure, the Square Kilometre Array Observatory (SKAO), and headquarters, are located at the Jodrell Bank Observatory in the United Kingdom. The SKA cores are being built in the southern hemisphere, where the view of the Milky Way galaxy is the best and radio interference is at its least. Conceived in the 1990s, and further developed and designed by the late-2010s, when completed a total collecting area of approximately one square kilometre. It will operate over a wide range of frequencies and its size will make it 50 times more sensitive than any other radio instrument. If built as planned, it should be able to survey the sky more than ten thousand times faster than before. With receiving stations extending out to a distance of at least from a concentrated central core, it will explo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low-Frequency Array
The Low-Frequency Array (LOFAR) is a large radio telescope, with an antenna network located mainly in the Netherlands, and spreading across 7 other European countries as of 2019. Originally designed and built by ASTRON, the Netherlands Institute for Radio Astronomy, it was first opened by Queen Beatrix of The Netherlands in 2010, and has since been operated by ASTRON on behalf first of the International LOFAR Telescope (ILT) partnership and now of the LOFAR ERIC by ASTRON. LOFAR consists of a vast array of omnidirectional radio antennas using a modern concept, in which the signals from the separate antennas are not connected directly electrically to act as a single large antenna, as they are in most array antennas. Instead, the LOFAR dipole antennas (of two types) are distributed in stations, within which the antenna signals can be partly combined in analogue electronics, then digitised, then combined again across the full station. This step-wise approach provides great flexibil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extremely Large Telescope
The Extremely Large Telescope (ELT) is an astronomical observatory under construction. When completed, it will be the world's largest optical and near-infrared extremely large telescope. Part of the European Southern Observatory (ESO) agency, it is located on top of Cerro Armazones in the Atacama Desert of northern Chile. The design consists of a reflecting telescope with a segmented primary mirror and a diameter secondary mirror. The telescope is equipped with adaptive optics, six laser guide star units, and various large-scale scientific instruments. The observatory's design will gather 100 million times more light than the human eye, equivalent to about 10 times more light than the largest optical telescopes in existence as of 2023, with the ability to correct for atmospheric distortion. It has around 250 times the light-gathering area of the Hubble Space Telescope and, according to the ELT's specifications, will provide images 15 times sharper than those from Hubble. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thirty Meter Telescope
The Thirty Meter Telescope (TMT) is a planned extremely large telescope (ELT) proposed to be built on Mauna Kea, on the Hawaii (island), island of Hawai'i. The TMT would become the largest visible-light telescope on Mauna Kea. Scientists have been considering ELTs since the mid 1980s. In 2000, astronomers considered the possibility of a telescope with a light-gathering mirror larger than in diameter, using either small segments that create one large mirror, or a grouping of larger mirrors working as one unit. The US National Academy of Sciences recommended a telescope be the focus of U.S. interests, seeking to see it built within the decade. Scientists at the University of California, Santa Cruz and Caltech began development of a design that would eventually become the TMT, consisting of a 492-segment primary mirror with nine times the power of the Keck Observatory. Due to its light-gathering power and the optimal observing conditions which exist atop Mauna Kea, the TMT wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ESO 0313-192
ESO 0313-192 (''also known as PGC 97372 and LO95 0313-192'') is an edge-on spiral galaxy, or a double-lobed radio galaxy located around 1 billion light-years away in the constellation Eridanus. Its radio jets were discovered in 2003 by NASA, and its radio lobes are an estimated 1.5 million light years in diameter. It is part of the cluster Abell 428, and it has an active galactic nuclei. Characteristics ESO 0313-192 has a spiral shape similar to that of the Milky Way. It has a large central bulge, and arms speckled with brightly glowing gas inhabited by thick lanes of dark dust. Its companion, sitting pretty in the right of the frame, is known rather unpoetically as OY2001J031549.8-190623. Jets, outbursts of superheated gas moving at close to the speed of light, have long been associated with the cores of giant elliptical galaxies, and galaxies in the process of merging. However, in an unexpected discovery, astronomers found ESO 0313-192 to have intense radio jets spewi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoch (astronomy)
In astronomy, an epoch or reference epoch is a instant, moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a Astronomical object, celestial body, as they are subject to Perturbation (astronomy), perturbations and vary with time. These time-varying astronomical quantities might include, for example, the mean longitude or mean anomaly of a body, the node of its orbit relative to a reference plane, the direction of the apogee or Perihelion and aphelion, aphelion of its orbit, or the size of the major axis of its orbit. The main use of astronomical quantities specified in this way is to calculate other relevant parameters of motion, in order to predict future positions and velocities. The applied tools of the disciplines of celestial mechanics or its subfield orbital mechanics (for predicting orbital paths and positions for bodies in motion under the gravitational effects of other bodi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virgo (constellation)
Virgo is one of the constellations of the zodiac. The name is for maiden in Latin and its traditional astrological symbol is . Between Leo (constellation), Leo to the west and Libra (constellation), Libra to the east, lying in the south, it is the second-largest constellation in the sky (after Hydra (constellation), Hydra) and the largest constellation in the zodiac. The ecliptic intersects the celestial equator within this constellation and Pisces (constellation), Pisces. Underlying these technical two definitions, the sun passes directly overhead of the equator, within this constellation, at the September equinox. Virgo can be easily found through its brightest star, Spica, (in Latin "grain headed"). Location Virgo is prominent in the spring sky in the Northern Hemisphere, visible all night in March and April. As the largest zodiac constellation, the Sun takes 44 days to pass through it, longer than any other. From 1990 and until 2062, this will take place from September 16 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
