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Encyclopedia > Supermassive black hole
Top: artist's conception of a supermassive black hole tearing apart a star. Bottom: images believed to show a supermassive black hole devouring a star in galaxy RXJ 1242-11. Left: X-ray image, Right: optical image.
Top: artist's conception of a supermassive black hole tearing apart a star. Bottom: images believed to show a supermassive black hole devouring a star in galaxy RXJ 1242-11. Left: X-ray image, Right: optical image.[1]

A supermassive black hole is a black hole with a mass of an order of magnitude between 105 and 1010 solar masses. Most, if not all galaxies, including the Milky Way, are believed to contain supermassive black holes at their centers.[citation needed] Alternate cover DVD Black Holes and Revelations track listing Starlight (2) Supermassive Black Hole (3) Map of the Problematique (4) Supermassive Black Hole is a song by English rock band Muse and is the third track on their 2006 album Black Holes and Revelations. ... Download high resolution version (540x637, 144 KB)Credit: Top: NASA/CXC/M.Weiss; Bottom left (X-ray): NASA/CXC/MPE/S.Komossa et al. ... Download high resolution version (540x637, 144 KB)Credit: Top: NASA/CXC/M.Weiss; Bottom left (X-ray): NASA/CXC/MPE/S.Komossa et al. ... For other uses, see Black hole (disambiguation). ... For other uses, see Mass (disambiguation). ... For other uses, see Galaxy (disambiguation). ... For other uses, see Milky Way (disambiguation). ...


Supermassive black holes have properties which distinguish them from their relatively low-mass cousins:

  • The average density of a supermassive black hole (measured as the mass of the black hole divided by its Schwarzschild volume) can be very low, and may actually be lower than the density of air. This is because the Schwarzschild radius is directly proportional to mass, while density is inversely proportional to the volume. Since the volume of a spherical object (such as the event horizon of a non-rotating black hole) is directly proportional to the cube of the radius, and mass merely increases linearly, the volume increases at a greater rate than mass. Thus, density decreases for increasingly larger radii of black holes. One should be aware however that this results from scientific definitions and does not necessarily manifest as a real physical property.
  • The tidal forces in the vicinity of the event horizon are significantly weaker. Since the central singularity is so far away from the horizon, a hypothetical astronaut travelling towards the black hole center would not experience significant tidal force until very deep into the black hole.

Contents

For other uses, see Density (disambiguation). ... Look up air in Wiktionary, the free dictionary. ... The Schwarzschild radius (sometimes inappropriately referred to as the gravitational radius[1]) is a characteristic radius associated with every mass. ... This article is about proportionality, the mathematical relation. ... For other uses, see Mass (disambiguation). ... Comet Shoemaker-Levy 9 after breaking up under the influence of Jupiters tidal forces. ... For the science fiction film, see Event Horizon (film). ... A gravitational singularity (sometimes spacetime singularity) is, approximately, a place where quantities which are used to measure the gravitational field become infinite. ... Click here for animated version Spaghettification is caused by the gravitational forces acting on the four objects. ...

Formation

An artist's conception of a supermassive black hole accreting from a disk. Credit: NASA/JPL-Caltech
An artist's conception of a supermassive black hole accreting from a disk. Credit: NASA/JPL-Caltech

There are several models for the formation of black holes of this size. The most obvious is by slow accretion of matter starting from a black hole of stellar size. Another model of supermassive black hole formation involves a large gas cloud collapsing into a relativistic star of perhaps a hundred thousand solar masses or larger. The star would then become unstable to radial perturbations due to electron-positron pair production in its core, and may collapse directly into a black hole without a supernova explosion, which would eject most of its mass preventing it from leaving a supermassive black hole as a remnant. Yet another model involves a dense stellar cluster undergoing core-collapse as the negative heat capacity of the system drives the velocity dispersion in the core to relativistic speeds. Finally, primordial black holes may have been produced directly from external pressure in the first instants after the Big Bang. Image File history File links Size of this preview: 750 × 600 pixelsFull resolution (3000 × 2400 pixel, file size: 1. ... Image File history File links Size of this preview: 750 × 600 pixelsFull resolution (3000 × 2400 pixel, file size: 1. ... For other uses, see NASA (disambiguation). ... The JPL complex in Pasadena, Ca. ... California Institute of Technology The California Institute of Technology (commonly known as Caltech) is a private, coeducational university located in Pasadena, California, in the United States. ... In astrophysics, the term accretion is used for at least two distinct processes. ... For other uses, see Supernova (disambiguation). ... -1... A black hole concept drawing by NASA A primordial black hole is a hypothetical type of black hole that is formed not by the gravitational collapse of a star but by the extreme density of matter present during the universes early expansion. ... For other uses, see Big Bang (disambiguation). ...


The difficulty in forming a supermassive black hole resides in the need for enough matter to be in a small enough volume. This matter needs to have very little angular momentum in order for this to happen. Normally the process of accretion involves transporting a large initial endowment of angular momentum outwards, and this appears to be the limiting factor in black hole growth, and explains the formation of accretion disks. Artists conception of a binary star system with one black hole and one main sequence star Unsolved problems in physics: Accretion disc jets: Why do the discs surrounding certain objects, such as the nuclei of active galaxies, emit radiation jets along their polar axes? These jets are invoked by...


Currently, there appears to be a gap in the observed mass distribution of black holes. There are stellar-mass black holes, generated from collapsing stars, which range up to perhaps 33 solar masses. The minimal supermassive black hole is in the range of a hundred thousand solar masses. Between these regimes there appears to be a dearth of objects. Such a gap would suggest qualitatively different formation processes. However, some models suggest that ultraluminous X-ray sources (ULXs) may be black holes from this missing group. An ultra-luminous X-ray source (ULX) is an astronomical source of X-rays that is not in the nucleus of a galaxy, and is more luminous than erg/s, assuming that it radiates isotropically. ...


Doppler measurements

Direct Doppler measures of water masers surrounding the nucleus of nearby galaxies have revealed a very fast keplerian motion, only possible with a high concentration of matter in the center. Currently, the only known objects that can pack enough matter in such a small space are black holes, or things that will evolve into black holes within astrophysically short timescales. For active galaxies farther away, the width of broad spectral lines can be used to probe the gas orbiting near the event horizon. The technique of reverberation mapping uses variability of these lines to measure the mass, and perhaps the spin of the black hole that powers the active galaxy's "engine". A source of waves moving to the left. ... An astrophysical maser is a naturally occurring source of stimulated spectral line emission, typically in the microwave portion of the electromagnetic spectrum. ... An active galaxy is a galaxy where a significant fraction of the energy output is not emitted by the normal components of a galaxy: stars, dust and interstellar gas. ... Johannes Kepler Johannes Kepler (December 27, 1571 – November 15, 1630), a key figure in the scientific revolution, was a German astronomer, mathematician and astrologer. ... An active galaxy is a galaxy where a significant fraction of the energy output is not emitted by the normal components of a galaxy: stars, dust and interstellar gas. ...


Such supermassive black holes in the center of many galaxies are thought to be the "engine" of active objects such as Seyfert galaxies and quasars. The Max Planck Institute for Extraterrestrial Physics and UCLA Galactic Center Group[2] provided evidence that Sagittarius A* is the supermassive black hole residing at the center of the Milky Way based on data from the ESO[3] and the Keck telescopes.[4] Our galactic central black hole is calculated to have a mass of 3.7 million solar masses.[5] An active galaxy is a galaxy where a significant fraction of the energy output is not emitted by the normal components of a galaxy: stars, dust and interstellar gas. ... Seyfert galaxies are spiral or irregular galaxies containing an extremely bright nucleus, most likely caused by a supermassive black hole, that can sometimes outshine the surrounding galaxy. ... This article is about the astronomical object. ... The Max Planck Institute for Extraterrestrial Physics is a Max Planck Institute, located in Garching, near Munich, Germany. ... Binomial name Ucla xenogrammus Holleman, 1993 The largemouth triplefin, Ucla xenogrammus, is a fish of the family Tripterygiidae and only member of the genus Ucla, found in the Pacific Ocean from Viet Nam, the Philippines, Palau and the Caroline Islands to Papua New Guinea, Australia (including Christmas Island), and the... Sagittarius A* (pronounced A-star) is a bright and very compact source of radio emission at the center of the Milky Way Galaxy, part of a larger astronomical feature at that location (Sagittarius A). ... For other uses, see Milky Way (disambiguation). ... The European Southern Observatory (ESO) is an international astronomical organisation, composed and supported by ten countries from the European Union plus Switzerland and was created in 1962. ... The Mauna Kea Observatory, an institute of the University of Hawaii, is considered one of the most important land-based observatories in the world for its isolated, unobstructed views of space without interference from man-made light sources. ...


Supermassive black holes outside the Milky Way

In May 2004, Paolo Padovani and collaborators announced their discovery of 30 previously hidden supermassive black holes outside the Milky Way. Their discovery also suggests there are at least twice as many of these black holes as previously thought. It is currently believed that every galaxy contains a supermassive black hole at its center, with most of them being in an "inactive" state not accreting much matter. In contrast, it is thought that black holes are not to be found in the center of globular clusters, although it's believed that some of them, like M15 in Pegasus and Mayall II in the Andromeda Galaxy have central black holes with a mass in the order of magnitude of 104 solar masses in their center. Paolo Padovani, was among a group of astronomers that discovered 30 previously-hidden super massive black holes outside the Mikly Way. ... The Globular Cluster M80 in the constellation Scorpius is located about 28,000 light years from the Sun and contains hundreds of thousands of stars. ... The central square arcminute of M15 imaged using the lucky imaging technique Globular Cluster M15 (also known as Messier Object 15 or NGC 7078) is a globular cluster in the constellation Pegasus. ... For other uses, see Pegasus (disambiguation). ... Mayall II, G1, SKHB 1, or HBK 0-1 is a globular cluster in M31, the Andromeda Galaxy. ... The Andromeda Galaxy (IPA: , also known as Messier 31, M31, or NGC 224; often referred to as the Great Andromeda Nebula in older texts) is a spiral galaxy approximately 2. ...


Some galaxies, Galaxy 0402+379 for example, have two supermassive black holes, forming a binary system. Should these collide, the event would create strong gravitational waves. Galaxy 0402+379 is a radio galaxy and elliptical galaxy with the binary supermassive blackholes with the least separation of any directly observed binaries, as of 2006. ... In physics, gravitational radiation is energy that is transmitted through waves in the gravitational field of space-time, according to Albert Einsteins theory of general relativity: The Einstein field equations imply that any accelerated mass radiates energy this way, in the same way as the Maxwell equations that any...


On January 8, 2008, the discovery of the most massive known black hole was announced at the American Astronomical Society meeting. It is reported to have a mass of 18 billion solar masses, and is known as OJ287.[6] The American Astronomical Society (AAS) is a US society of professional astronomers and other interested individuals, headquartered in Washington, DC. The main aim of the AAS is provide a political voice for its members and organise their lobbying. ...


Supermassive black hole mass and galaxy formation

There appears to be a link between the mass of the supermassive black hole in the center of a galaxy and the morphology of the galaxy itself. This manifests as a correlation between the mass of the spheroid (the bulge of spiral galaxies, and the whole galaxy for ellipticals) and the mass of the supermassive black hole. There is an even tighter correlation between the black hole mass and the velocity dispersion of the spheroid. The explanation for this correlation remains an unsolved problem in astrophysics.


See also

An active galaxy is a galaxy where a significant fraction of the energy output is not emitted by the normal components of a galaxy: stars, dust and interstellar gas. ... The Double Helix Nebula is a gaseous nebula near the center of our galaxy, which is thought to have been distorted by magnetic torsion into the shape of two connected spirals, known popularly as a double helix, akin to the shape of DNA. The nebula was discovered by the Spitzer... For other uses, see Galaxy (disambiguation). ... For the series of books, see Galactic Center Saga. ... A Magnetospheric Eternally Collapsing Object or MECO is a proposed alternative to a black hole. ... For the story by Larry Niven, see Neutron Star (story). ... This article is about the astronomical object. ... Sagittarius A* (pronounced A-star) is a bright and very compact source of radio emission at the center of the Milky Way Galaxy, part of a larger astronomical feature at that location (Sagittarius A). ... For other uses, see Black hole (disambiguation). ... Projected timeline of the Suns life In astronomy, stellar evolution is the process by which a star undergoes a sequence of radical changes during its lifetime. ... This article or section does not cite its references or sources. ... In astronomy, the term compact star (sometimes compact object) is used to refer collectively to white dwarfs, neutron stars, other exotic dense stars, and black holes. ... This article is in need of attention from an expert on the subject. ... A black hole concept drawing by NASA A primordial black hole is a hypothetical type of black hole that is formed not by the gravitational collapse of a star but by the extreme density of matter present during the universes early expansion. ... A black hole concept drawing by NASA. Taken from: http://www. ... A rotating black hole (Kerr black hole or Kerr-Newman black hole) is a black hole that possesses angular momentum. ... A charged black hole is a black hole that possesses electric charge. ... The Schwarzschild radius (sometimes inappropriately referred to as the gravitational radius[1]) is a characteristic radius associated with every mass. ... This article or section is in need of attention from an expert on the subject. ... A stellar black hole is a black hole formed by the gravitational collapse of a massive star (3 or more solar masses) at the end of its lifetime. ... An Intermediate-mass black hole (IMBH) is a black hole whose mass is significantly more than stellar black holes (a few tens of the mass of Sun) yet far less than supermassive black holes (a few millions of the mass of Sun). ... For the science fiction film, see Event Horizon (film). ... A gravitational singularity (sometimes spacetime singularity) is, approximately, a place where quantities which are used to measure the gravitational field become infinite. ... A photon sphere is a spherical region of space surrounding extremely massive objects such as black holes. ... A rotating black hole (Kerr black hole or Kerr-Newman black hole) is a black hole that possesses angular momentum. ... In physics, Hawking radiation (also known as Bekenstein-Hawking radiation) is a thermal radiation thought to be emitted by black holes due to quantum effects. ... It has been suggested that Deriving the Schwarzschild solution be merged into this article or section. ... In general relativity, the Kerr metric (or Kerr vacuum) describes the geometry of spacetime around a rotating massive body, such as a rotating black hole. ... In physics and astronomy, a Reissner-Nordström black hole, discovered by Gunnar Nordström and Hans Reissner, is a black hole that carries electric charge , no angular momentum, and mass . ... The Kerr-Newman metric is a solution of Einsteins general relativity field equation that describes the spacetime geometry around a charged (), rotating () black hole of mass m. ... In astrophysics, the no-hair theorem states that black holes are completely characterized only by three externally observable parameters: mass, electrical charge, and angular momentum. ... This article or section cites very few or no references or sources. ... It has been suggested that Naked singularity be merged into this article or section. ...

Further reading

  • Fulvio Melia (2003). The Edge of Infinity. Supermassive Black Holes in the Universe. Cambridge University Press. ISBN 978-0-521-81405-8. 
  • Fulvio Melia (2007). The Galactic Supermassive Black Hole. Princeton University Press. ISBN 978-0-691-13129-0. 

This article does not cite its references or sources. ... This article does not cite its references or sources. ...

References

  1. ^ Chandra :: Photo Album :: RX J1242-11 :: 18 Feb 04
  2. ^ UCLA Galactic Center Group
  3. ^ ESO - 2002
  4. ^ http://www.keckobservatory.org/news/old_pages/andreaghez.html
  5. ^ UCLA Galactic Center Group
  6. ^ SPACE.com - Colossal Black Hole Shatters the Scales
  • Julian H. Krolik (1999). Active Galactic Nuclei. Princeton University Press. ISBN 0-691-01151-6. 

External links

  • Black Holes: Gravity's Relentless Pull Award-winning interactive multimedia Web site about the physics and astronomy of black holes from the Space Telescope Science Institute
The European Southern Observatory (ESO) is an international astronomical organisation, composed and supported by ten countries from the European Union plus Switzerland and was created in 1962. ... is the 294th day of the year (295th in leap years) in the Gregorian calendar. ... Also see: 2002 (number). ...

  Results from FactBites:
 
supermassive black hole (619 words)
The energy generated by the jets that accompany the growth of the supermassive fl hole eventually brings the in-fall of matter and the growth of the galaxy to a halt.
If the accretion disk of the central fl hole is well supplied with matter falling in from the immediate surroundings of the galactic nucleus, then it will generate large amounts of energy together with powerful jets of radiation in both directions along the rotation axis of the fl hole.
Supermassive fl holes and their associated accretion disks were particularly big energy producers in the early universe when galaxies were still young and their inner regions well stocked with material that could feed the central engine.
Supermassive black hole - Wikipedia, the free encyclopedia (944 words)
The process of transporting this angular momentum outwards appears to be the constraining factor in fl hole growth, and leads to the formation of accretion disks.
Such supermassive fl holes in the center of many galaxies are thought to be the "engine" of active objects such as Seyfert galaxies and quasars.
This manifests as a correlation between the mass of the spheroid (the bulge of spiral galaxies, and the whole galaxy for ellipticals) and the mass of the supermassive fl hole.
  More results at FactBites »

 
 

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