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Microquasar
A microquasar, a smaller version of a quasar, is a compact region surrounding a stellar black hole with a mass several times that of its companion star, observable in sufficient details, in our own or nearby galaxy. The matter being pulled from the companion star forms an accretion disk around the black hole. This accretion disk may become so hot, due to friction, that it begins to emit X-rays. The disk also projects narrow streams or " jets" of subatomic particles at near- light speed, generating a strong radio wave emission. Overview In 1979, SS 433, in our own galaxy, became the first microquasar to be discovered, when Margon et al. observed its relativistic jets. It was thought to be the most exotic case until similar objects such as GRS 1915+105 were confirmed in 1994. In some cases, blobs or "knots" of brighter plasma within the jets appear to be traveling faster than the speed of light, an optical illusion called superluminal motion which is caused by sub-light-spee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Microquasars ...
This is a list of all known microquasars: 1 * 1E 1740,7-2942 4 * 4U1630-47 C *Cygnus X-1 * Cygnus X-3 (V1521) * CI Cam G *GRS 1915+105 * GRO J1655-40 * GX339-4 K * KS1731-260 L * LS I +61 303 * LS 5039 S * Scorpius X-1 * SS 433 V * V404 Cygni * V4641 Sgr * V691 CrA X * XMMU J004243.6+412519 * XTE J1118+480 * XTE J1550-564 See also * List of quasars References {{black holes * microquasars A microquasar, a smaller version of a quasar, is a compact region surrounding a stellar black hole with a mass several times that of its Binary star#Cataclysmic variables and X-ray binaries, companion star, observable in sufficient details, in Mil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GRS 1915+105
GRS 1915+105 or V1487 Aquilae is an X-ray binary star system containing a main sequence star and a black hole. Transfer of material from the star to the black hole generates a relativistic jet, making this a microquasar system. The jet exhibits apparent superluminal motion. It was discovered on August 15, 1992 by the WATCH all-sky monitor aboard Granat. "GRS" stands for "GRANAT source", "1915" is the right ascension (19 hours and 15 minutes) and "105" reflects the approximate declination (10 degrees and 56 arcminutes). The near-infrared counterpart was determined by spectroscopic observations. The binary system lies 11,000 parsecs away in Aquila. The black hole in GRS 1915+105 is 10 to 18 solar masses. The black hole rotates at least 950 times per second, giving it a spin parameter >0.82 (1.0 is the theoretical maximum). Galactic superluminal source In 1994, GRS 1915+105 became the first known galactic source that ejects material with apparent superluminal motion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microquasars
A microquasar, a smaller version of a quasar, is a compact region surrounding a stellar black hole with a mass several times that of its Binary star#Cataclysmic variables and X-ray binaries, companion star, observable in sufficient details, in Milky Way, our own or nearby galaxy. The matter being pulled from the companion star forms an accretion disk around the black hole. This accretion disk may become so hot, due to friction, that it begins to emit X-rays. The disk also projects narrow streams or "Astrophysical jet, jets" of subatomic particles at near-Speed of light, light speed, generating a strong radio wave emission. Overview In 1979, SS 433, in our own galaxy, became the first microquasar to be discovered, when Margon et al. observed its relativistic jets. It was thought to be the most exotic case until similar objects such as GRS 1915+105 were confirmed in 1994. In some cases, blobs or "knots" of brighter plasma (physics), plasma within the jets appear to be traveling fast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SS 433
SS 433 is a microquasar or eclipsing X-ray binary system, consisting of a stellar-mass black hole accreting matter from an A-type companion star. SS 433 is the first discovered microquasar. It is at the centre of the supernova remnant W50. SS 433's designation comes from the initials of two astronomers at Case Western Reserve University: Nicholas Sanduleak and Charles Bruce Stephenson. It was the 433rd entry in their 1977 catalog of stars with strong emission lines.SS 433 David Darling, entry in ''The Internet Encyclopedia of Science'', accessed on line September 14, 2007. Its emission lines were studied by Mordehai Milgrom in 1979. Location SS 433, also known as V1343 Aquilae, located in the gala ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ss433 Art Big
SS 433 is a microquasar or eclipsing X-ray binary system, consisting of a stellar-mass black hole accreting matter from an A-type companion star. SS 433 is the first discovered microquasar. It is at the centre of the supernova remnant W50. SS 433's designation comes from the initials of two astronomers at Case Western Reserve University: Nicholas Sanduleak and Charles Bruce Stephenson. It was the 433rd entry in their 1977 catalog of stars with strong emission lines.SS 433 David Darling, entry in ''The Internet Encyclopedia of Science'', accessed on line September 14, 2007. Its emission lines were studied by Mordehai Milgrom in 1979. Location SS 433, also known as V1343 Aquilae, located in the galac ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Annihilator
1E1740.7-2942, or the Great Annihilator, is a Milky Way microquasar, located near the Galactic Center on the sky. It likely consists of a black hole and a companion star. It is one of the brightest X-ray sources in the region around the Galactic Center. The object was first detected in soft X-rays by the Einstein Observatory, and later detected in hard X-rays by the Soviet Granat space observatory. Followup observations by the SIGMA detector on board Granat showed that the object was a variable emitter of massive amounts of photon pairs at 511 keV, which usually indicates the annihilation of an electron-positron pair. This led to the nickname, "Great Annihilator." Early observations also showed a spectrum similar to that of the Cygnus X-l, a black hole with a stellar companion, which suggested that Great Annihilator was also a stellar mass black hole. The object also has a radio source counterpart that emits jets approximately 1.5 pc (5 ly) long. These jets are probably ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quasar
A quasar ( ) is an extremely Luminosity, luminous active galactic nucleus (AGN). It is sometimes known as a quasi-stellar object, abbreviated QSO. The emission from an AGN is powered by accretion onto a supermassive black hole with a mass ranging from millions to tens of billions of solar masses, surrounded by a gaseous Accretion disk, accretion disc. Gas in the disc falling towards the black hole heats up and releases energy in the form of electromagnetic radiation. The radiant energy of quasars is enormous; the most powerful quasars have luminosity, luminosities thousands of times greater than that of a galaxy such as the Milky Way. Quasars are usually categorized as a subclass of the more general category of AGN. The redshifts of quasars are of Expansion of the universe, cosmological origin. The term originated as a Contraction (grammar), contraction of "quasi-stellar ''[star-like]'' radio source"—because they were first identified during the 1950s as sources of radio-wave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Star
A binary star or binary star system is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved as separate stars using a telescope, in which case they are called ''visual binaries''. Many visual binaries have long orbital periods of several centuries or millennia and therefore have orbits which are uncertain or poorly known. They may also be detected by indirect techniques, such as spectroscopy (''spectroscopic binaries'') or astrometry (''astrometric binaries''). If a binary star happens to orbit in a plane along our line of sight, its components will eclipse and transit each other; these pairs are called ''eclipsing binaries'', or, together with other binaries that change brightness as they orbit, ''photometric binaries''. If components in binary star systems are close enough, they can gravitationally distort each other's outer stellar atmospheres. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star
A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sky, night; their immense distances from Earth make them appear as fixed stars, fixed points of light. The most prominent stars have been categorised into constellations and asterism (astronomy), asterisms, and many of the brightest stars have proper names. Astronomers have assembled star catalogues that identify the known stars and provide standardized stellar designations. The observable universe contains an estimated to stars. Only about 4,000 of these stars are visible to the naked eye—all within the Milky Way galaxy. A star's life star formation, begins with the gravitational collapse of a gaseous nebula of material largely comprising hydrogen, helium, and traces of heavier elements. Its stellar mass, total mass mainly determines it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bruno Rossi Prize
The Bruno Rossi Prize is awarded annually by the High Energy Astrophysics division of the American Astronomical Society "for a significant contribution to High Energy Astrophysics, with particular emphasis on recent, original work". Named after astrophysicist Bruno Rossi, the prize is awarded with a certificate and a gift of USD $500, and was first awarded in 1985 to William R. Forman and Christine Jones Forman "for pioneering work in the study of X-ray emission from early type galaxies". It has been awarded 40 times. In 2010, the prize was awarded to William B. Atwood, Peter Michelson and the Fermi Gamma-ray Space Telescope team "for enabling, through the development of the Large Area Telescope, new insights into neutron stars, supernova remnants, cosmic rays, binary systems, active galactic nuclei, and gamma-ray bursts". In 2013, the prize was awarded to Roger W. Romani of Leland Stanford Junior University and Alice Harding of Goddard Space Flight Center for their work in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Black Hole
A stellar black hole (or stellar-mass black hole) is a black hole formed by the gravitational collapse of a star. They have masses ranging from about 5 to several tens of solar masses. They are the remnants of supernova explosions, which may be observed as a type of gamma ray burst. These black holes are also referred to as collapsars. Properties By the no-hair theorem, a black hole can only have three fundamental properties: mass, electric charge, and angular momentum. The angular momentum of a stellar black hole is due to the conservation of angular momentum of the star or objects that produced it. The gravitational collapse of a star is a natural process that can produce a black hole. It is inevitable at the end of the life of a massive star when all stellar energy sources are exhausted. If the mass of the collapsing part of the star is below the TOV limit, Tolman–Oppenheimer–Volkoff (TOV) limit for Degenerate matter#Neutron degeneracy, neutron-degenerate matter, the end ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parsec
The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to or (AU), i.e. . The parsec unit is obtained by the use of parallax and trigonometry, and is defined as the distance at which 1 AU subtended angle, subtends an angle of one arcsecond ( of a degree (angle), degree). The nearest star, Proxima Centauri, is about from the Sun: from that distance, the gap between the Earth and the Sun spans slightly less than one arcsecond. Most Naked-eye stars, stars visible to the naked eye are within a few hundred parsecs of the Sun, with the most distant at a few thousand parsecs, and the Andromeda Galaxy at over 700,000 parsecs. The word ''parsec'' is a shortened form of ''a distance corresponding to a parallax of one second'', coined by the British astronomer Herbert Hall Turner in 1913. The unit was introduced to simplify the calculation of astronomical distances from raw observational data. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
