Artist concept of a SMBH consumingmatter from a nearby star.

This artist’s impression shows thesurroundings of a supermassive blackhole, typical of that found at the heartof many galaxies. The black holeitself is surrounded by a brilliantaccretion disc of very hot, infallingmaterial and, further out, a dustytorus. There are also often high-speedjets of material ejected at the blackhole’s poles that can extend hugedistances into space. Observationswith ALMA have detected a verystrong magnetic field close to theblack hole at the base of the jets andthis is probably involved in jetproduction and collimation.

An artist's conception of asupermassive black hole andaccretion disk

Supermassive black holeFrom Wikipedia, the free encyclopedia

A supermassive black hole (SMBH) is the largest type of black hole, on the order of hundreds of thousands to billionsof solar masses (M☉), and is found in the center of almost all currently known massive galaxies.[1][2] In the case of theMilky Way, the SMBH corresponds with the location of Sagittarius A*.[3][4]

Supermassive black holes have properties that distinguish them from lower-mass classifications. First, the averagedensity of a supermassive black hole (defined as the mass of the black hole divided by the volume within itsSchwarzschild radius) can be less than the density of water in the case of some supermassive black holes.[5] This isbecause 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 proportionalto the cube of the radius, the minimum density of a black hole is inversely proportional to the square of the mass, andthus higher mass black holes have lower average density. In addition, the tidal forces in the vicinity of the event horizonare significantly weaker for massive black holes. As with density, the tidal force on a body at the event horizon isinversely proportional to the square of the mass: a person on the surface of the Earth and one at the event horizon of a10 million M☉ black hole experience about the same tidal force between their head and feet. Unlike with stellar massblack holes, one would not experience significant tidal force until very deep into the black hole.

Contents1 History of research2 Formation3 Doppler measurements4 In the Milky Way5 Outside the Milky Way6 In fiction7 See also8 References9 Further reading10 External links

History of researchDonald Lynden-Bell and Martin Rees hypothesized in 1971 that the center of the Milky Way galaxy would contain asupermassive black hole. Sagittarius A* was discovered and named on February 13 and 15, 1974, by astronomersBruce Balick and Robert Brown using the baseline interferometer of the National Radio Astronomy Observatory.[6] They discovered a radio source that emitssynchrotron radiation; it was found to be dense and immobile because of its gravitation. This was, therefore, the first indication that a supermassive black holeexists in the center of the Milky Way.

FormationThe origin of supermassive black holes remains an open field of research. Astrophysicists agree that once a black hole is inplace in the center of a galaxy, it can grow by accretion of matter and by merging with other black holes. There are,however, several hypotheses for the formation mechanisms and initial masses of the progenitors, or "seeds", ofsupermassive black holes. The most obvious hypothesis is that the seeds are black holes of tens or perhaps hundreds ofsolar masses that are left behind by the explosions of massive stars and grow by accretion of matter. Another modelinvolves a large gas cloud in the period before the first stars formed collapsing into a “quasi-star” and then a black hole ofinitially only around ~20 M☉, and then rapidly accreting to become relatively quickly an intermediate-mass black hole,and possibly a SMBH if the accretion-rate is not quenched at higher masses.[7] The initial “quasi-star” would becomeunstable to radial perturbations because of electron-positron pair production in its core, and may collapse directly into ablack hole without a supernova explosion, which would eject most of its mass and prevent it from leaving a black hole as aremnant.

Yet another model[10] involves a dense stellar cluster undergoing core-collapse as the negative heat capacity of the systemdrives the velocity dispersion in the core to relativistic speeds. Finally, primordial black holes may have been produced

directly from external pressure in the first moments after the Big Bang. Formation of black holes from the deaths of the first stars has been extensively studiedand corroborated by observations. The other models for black hole formation listed above are theoretical.

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 littleangular momentum in order for this to happen. Normally, the process of accretion involves transporting a large initial endowment of angular momentumoutwards, and this appears to be the limiting factor in black hole growth. This is a major component of the theory of accretion disks. Gas accretion is the mostefficient and also the most conspicuous way in which black holes grow. The majority of the mass growth of supermassive black holes is thought to occurthrough episodes of rapid gas accretion, which are observable as active galactic nuclei or quasars. Observations reveal that quasars were much more frequentwhen the Universe was younger, indicating that supermassive black holes formed and grew early. A major constraining factor for theories of supermassiveblack hole formation is the observation of distant luminous quasars, which indicate that supermassive black holes of billions of solar masses had already

1 of 5

Artist's impression of the hugeoutflow ejected from the quasarSDSS J1106+1939[8]

Artist's illustration of galaxy withjets from a supermassive blackhole.[9]

Side view of black hole withtransparent toroidal ring of ionisedmatter according to a proposed model[12] for Sgr A*. This image showsresult of bending of light from behindthe black hole, and it also shows theasymmetry arising by the Dopplereffect from the extremely high orbitalspeed of the matter in the ring.

Inferred orbits of 6 stars aroundsupermassive black hole candidateSagittarius A* at the Milky Waygalactic centre[14]

formed when the Universe was less than one billion years old. This suggests that supermassive black holes arose veryearly in the Universe, inside the first massive galaxies.

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 M☉. The minimal supermassive black hole is in the rangeof a hundred thousand solar masses. Between these regimes there appears to be a dearth of intermediate-mass blackholes. Such a gap would suggest qualitatively different formation processes. However, some models[11] suggest thatultraluminous X-ray sources (ULXs) may be black holes from this missing group.

Doppler measurementsSome of the best evidence for the presence of black holes is provided by the Doppler effect whereby light from nearbyorbiting matter is redshifted when receding and blue shifted when advancing. For matter very close to a black hole theorbital speed must be comparable with the speed of light, so receding matter will appear very faint compared withadvancing matter, which means that systems with intrinsically symmetric discs and rings will acquire a highlyasymmetric visual appearance. This effect has been allowed for in modern computer generated images such as theexample presented here, based on a plausible model [12] for the supermassive black hole in Sgr A* at the centre of ourown galaxy. However the resolution provided by presently available telescope technology is still insufficient to confirmsuch predictions directly.

What already has been observed directly in many systems are the lower non-relativistic velocities of matter orbitingfurther out from what are presumed to be black holes. Direct Doppler measures of water masers surrounding the nucleiof nearby galaxies have revealed a very fast Keplerian motion, only possible with a high concentration of matter in thecenter. Currently, the only known objects that can pack enough matter in such a small space are black holes, or thingsthat will evolve into black holes within astrophysically short timescales. For active galaxies farther away, the width ofbroad spectral lines can be used to probe the gas orbiting near the event horizon. The technique of reverberationmapping uses variability of these lines to measure the mass and perhaps the spin of the black hole that powers activegalaxies.

Gravitation from supermassive black holes in the center of many galaxies is thought to power active objects such asSeyfert galaxies and quasars.

An empirical correlation between the size of supermassive black holes and the stellar velocity dispersion of a galaxybulge[13] is called the M-sigma relation.

In the Milky WayAstronomers are very confident that our own Milky Way galaxy has a supermassive black hole at its center, 26,000light-years from the Solar System, in a region called Sagittarius A*[15] because:

The star S2 follows an elliptical orbit with a period of 15.2 years and a pericenter (closest distance) of 17light-hours (1.8 ×1013 m or 120 AU) from the center of the central object.[16]

From the motion of star S2, the object's mass can be estimated as 4.1 million M☉,[17][18] or about 8.2 ×1036 kg.The radius of the central object must be less than 17 light-hours, because otherwise, S2 would collide with it. Infact, recent observations from the star S14[19] indicate that the radius is no more than 6.25 light-hours, about thediameter of Uranus' orbit. However, applying the formula for the Schwarzschild radius yields just about 41 light-seconds, making it consistent with the escape velocity being the speed of light.No known astronomical object other than a black hole can contain 4.1 million M☉ in this volume of space.

The Max Planck Institute for Extraterrestrial Physics and UCLA Galactic Center Group[20] have provided the strongestevidence to date that Sagittarius A* is the site of a supermassive black hole,[15] based on data from ESO's Very LargeTelescope[21] and the Keck telescope.[22]

On 5 January 2015, NASA reported observing an X-ray flare 400 times brighter than usual, a record-breaker, fromSagittarius A*. The unusual event may have been caused by the breaking apart of an asteroid falling into the black holeor by the entanglement of magnetic field lines within gas flowing into Sagittarius A*, according to astronomers.[23]

2 of 5

Artists impression of a supermassiveblack hole tearing apart a star. Below:supermassive black hole devouring astar in galaxy RX J1242-11 – X-ray(left) and optical (right).[24]

Hubble Space Telescope photographof the 4,400 light-year longrelativistic jet of Messier 87, which ismatter being ejected by the 6.4 ×109

M☉ supermassive black hole at thecenter of the galaxy

Detection of an unusually bright X-Ray flare from Sagittarius A*, asupermassive black hole in the center of the Milky Way galaxy[23]

Outside the Milky Way

Unambiguous dynamical evidence for supermassive black holes exists only in a handful of galaxies;[25] these includethe Milky Way, the Local Group galaxies M31 and M32, and a few galaxies beyond the Local Group, e.g. NGC 4395.In these galaxies, the mean square (or rms) velocities of the stars or gas rises as ~1/r near the center, indicating a centralpoint mass. In all other galaxies observed to date, the rms velocities are flat, or even falling, toward the center, makingit impossible to state with certainty that a supermassive black hole is present.[25] Nevertheless, it is commonly acceptedthat the center of nearly every galaxy contains a supermassive black hole.[26] The reason for this assumption is theM-sigma relation, a tight (low scatter) relation between the mass of the hole in the ~10 galaxies with secure detections,and the velocity dispersion of the stars in the bulges of those galaxies.[27] This correlation, although based on just ahandful of galaxies, suggests to many astronomers a strong connection between the formation of the black hole and thegalaxy itself.[26]

The nearby Andromeda Galaxy, 2.5 million light-years away, contains a(1.1–2.3) × 108 (110-230 million) M☉ central black hole, significantly largerthan the Milky Way's.[28] The largest supermassive black hole in the MilkyWay's vicinity appears to be that of M87, weighing in at (6.4 ± 0.5) × 109 (~6.4billion) M☉ at a distance of 53.5 million light-years.[29][30] On 5 December2011 astronomers discovered the largest supermassive black hole in the nearbyuniverse yet found, that of the supergiant elliptical galaxy NGC 4889, weighingin at 2.1 ×1010 (21 billion) M☉ at a distance of 336 million light-years away inthe Coma Berenices constellation.[31] Meanwhile, the supergiant ellipticalgalaxy at the center of the Phoenix Cluster hosts a black hole of 2.0 ×1010 (20 billion) M☉ at a distance of 5.7 billionlight years. Black holes in quasars are much larger, due to their active state of continuous growing phase. Thehyperluminous quasar APM 08279+5255 has a supermassive black hole with a mass of 2.3 ×1010 (23 billion) M☉.Larger still is at another hyperluminous quasar S5 0014+81, the largest supermassive black hole yet found, whichweighs in at 4.0 ×1010 (40 billion) M☉, or 10,000 times the size of the black hole at the Milky Way Galactic Center.Both quasars are 12.1 billion light years away.

Some galaxies, such as Galaxy 0402+379, appear to have two supermassive black holes at their centers, forming abinary system. If they collided, the event would create strong gravitational waves.[32] Binary supermassive black holesare believed to be a common consequence of galactic mergers.[33] The binary pair in OJ 287, 3.5 billion light-years

away, contains the most massive black hole in a pair, with a mass estimated at 18 billion M☉.[34] A supermassive black hole was recently discovered in thedwarf galaxy Henize 2-10, which has no bulge. The precise implications for this discovery on black hole formation are unknown, but may indicate that blackholes formed before bulges.[35]

On March 28, 2011, a supermassive black hole was seen tearing a mid-size star apart.[36] That is the only likely explanation of the observations that day ofsudden X-ray radiation and the follow-up broad-band observations.[37][38] The source was previously an inactive galactic nucleus, and from study of theoutburst the galactic nucleus is estimated to be a SMBH with mass of the order of a million solar masses. This rare event is assumed to be a relativistic outflow(material being emitted in a jet at a significant fraction of the speed of light) from a star tidally disrupted by the SMBH. A significant fraction of a solar mass ofmaterial is expected to have accreted onto the SMBH. Subsequent long-term observation will allow this assumption to be confirmed if the emission from thejet decays at the expected rate for mass accretion onto a SMBH.

In 2012, astronomers reported an unusually large mass of approximately 17 billion M☉ for the black hole in the compact, lenticular galaxy NGC 1277, which

3 of 5

A gas cloud with several times themass of the Earth is acceleratingtowards a supermassive black hole atthe centre of the Milky Way.

lies 220 million light-years away in the constellation Perseus. The putative black hole has approximately 59 percent ofthe mass of the bulge of this lenticular galaxy (14 percent of the total stellar mass of the galaxy).[39] Another studyreached a very different conclusion: this black hole is not particularly overmassive, estimated at between 2 and 5 billionM☉ with 5 billion M☉ being the most likely value.[40] On 28 February 2013 astronomers reported on the use of theNuSTAR satellite to accurately measure the spin of a supermassive black hole for the first time, in NGC 1365, reportingthat the event horizon was spinning at almost the speed of light.[41][42]

In September 2014, data from different X-ray telescopes has shown that the extremely small, dense, ultracompact dwarfgalaxy M60-UCD1 hosts a 20 million solar mass black hole at its center, accounting for more than 10% of the totalmass of the galaxy. The discovery is quite surprising, since the black hole is five times more massive than the MilkyWay's black hole despite the galaxy being less than five-thousandth the mass of the Milky Way.

Some galaxies, however, lack any supermassive black holes in their centers. Although most galaxies with nosupermassive black holes are very small, dwarf galaxies, one discovery remains mysterious: The supergiant elliptical cD galaxy A2261-BCG has not beenfound to contain an active supermassive black hole, despite the galaxy being one of the largest galaxies known; ten times the size and one thousand times themass of the Milky Way. Since a supermassive black hole will only be visible while it is accreting, a supermassive black hole can be nearly invisible, except inits effects on stellar orbits.

In fiction

See alsoActive galactic nucleusCentral massive objectGalactic centerGeneral relativity

Hypercompact stellar systemList of most massive black holesM-sigma relationSpin-flip

References

Antonucci, R. (1993). "Unified Models for Active Galactic Nuclei andQuasars". Annual Review of Astronomy and Astrophysics 31 (1): 473–521.Bibcode:1993ARA&A..31..473A. doi:10.1146/annurev.aa.31.090193.002353.

1.

Urry, C.; Padovani, P. (1995). "Unified Schemes for Radio-Loud ActiveGalactic Nuclei". Publications of the Astronomical Society of the Pacific 107:803–845. arXiv:astro-ph/9506063. Bibcode:1995PASP..107..803U.doi:10.1086/133630.

2.

Schödel, R.; et al. (2002). "A star in a 15.2-year orbit around the supermassiveblack hole at the centre of the Milky Way". Nature 419 (6908): 694–696.arXiv:astro-ph/0210426. Bibcode:2002Natur.419..694S.doi:10.1038/nature01121. PMID 12384690.

3.

Overbye, Dennis (8 June 2015). "Black Hole Hunters". NASA. Retrieved 8 June2015.

4.

Celotti, A.; Miller, J.C.; Sciama, D.W. (1999). "Astrophysical evidence for theexistence of black holes". Class. Quant. Grav. 16 (12A): A3–A21. arXiv:astro-ph/9912186. doi:10.1088/0264-9381/16/12A/301.

5.

Melia 2007, p. 2.6. Begelman, M. C.; et al. (Jun 2006). "Formation of supermassive black holes bydirect collapse in pre-galactic haloed". Monthly Notices of the RoyalAstronomical Society 370 (1): 289–298. arXiv:astro-ph/0602363.Bibcode:2006MNRAS.370..289B. doi:10.1111/j.1365-2966.2006.10467.x.

7.

"Biggest Black Hole Blast Discovered". ESO Press Release. Retrieved28 November 2012.

8.

"Artist’s illustration of galaxy with jets from a supermassive black hole".Retrieved 8 June 2015.

9.

Spitzer, L. (1987). Dynamical Evolution of Globular Clusters. PrincetonUniversity Press. ISBN 0-691-08309-6.

10.

Winter, L.M.; et al. (Oct 2006). "XMM-Newton Archival Study of the ULXPopulation in Nearby Galaxies". Astrophysical Journal 649 (2): 730–752.arXiv:astro-ph/0512480. Bibcode:2006ApJ...649..730W. doi:10.1086/506579.

11.

O. Straub, F.H. Vincent, M.A. Abramowicz, E. Gourgoulhon, T. Paumard,``Modelling the black hole silhouette in Sgr A* with ion tori, Astron. Astroph.543} (2012) A83.

12.

Gultekin K; et al. (2009). "The M and M-L Relations in Galactic Bulges,and Determinations of Their Intrinsic Scatter". The Astrophysical Journal 698(1): 198–221. arXiv:0903.4897. Bibcode:2009ApJ...698..198G.doi:10.1088/0004-637X/698/1/198.

13.

Eisenhauer; et al. (2005). "SINFONI in the Galactic Center: Young Stars andInfrared Flares in the Central Light-Month". The Astrophysical Journal 628:246–259. arXiv:astro-ph/0502129. Bibcode:2005ApJ...628..246E.doi:10.1086/430667.

14.

Henderson, Mark (December 9, 2008). "Astronomers confirm black hole at theheart of the Milky Way". London: Times Online. Retrieved 2009-05-17.

15.

Schödel, R.; et al. (17 October 2002). "A star in a 15.2-year orbit around thesupermassive black hole at the centre of the Milky Way". Nature 419 (6908):694–696. arXiv:astro-ph/0210426. Bibcode:2002Natur.419..694S.doi:10.1038/nature01121. PMID 12384690.

16.

Ghez, A. M.; et al. (December 2008). "Measuring Distance and Properties of the17.

Milky Way's Central Supermassive Black Hole with Stellar Orbits".Astrophysical Journal 689 (2): 1044–1062. arXiv:0808.2870.Bibcode:2008ApJ...689.1044G. doi:10.1086/592738.Milky Way's Central Monster Measured (http://www.skyandtelescope.com/astronomy-news/milky-ways-central-monster-measured/)

18.

Ghez, A. M.; Salim, S.; Hornstein, S. D.; Tanner, A.; Lu, J. R.; Morris, M.;Becklin, E. E.; Duchêne, G. (May 2005). "Stellar Orbits around the GalacticCenter Black Hole". The Astrophysical Journal 620 (2): 744–757. arXiv:astro-ph/0306130. Bibcode:2005ApJ...620..744G. doi:10.1086/427175.

19.

UCLA Galactic Center Group (http://www.astro.ucla.edu/~ghezgroup/gc/)20. ESO - 2002 (http://www.eso.org/outreach/press-rel/pr-2002/pr-17-02.html)21. "| W. M. Keck Observatory". Keckobservatory.org. Retrieved 2013-07-14.22. Chou, Felicia; Anderson, Janet; Watzke, Megan (5 January 2015). "RELEASE15-001 - NASA’s Chandra Detects Record-Breaking Outburst from MilkyWay’s Black Hole". NASA. Retrieved 6 January 2015.

23.

Chandra :: Photo Album :: RX J1242-11 :: 18 Feb 04(http://chandra.harvard.edu/photo/2004/rxj1242/)

24.

Merritt, David (2013). Dynamics and Evolution of Galactic Nuclei. Princeton,NJ: Princeton University Press. p. 23. ISBN 9780691158600.

25.

King, Andrew (2003-09-15). "Black Holes, Galaxy Formation, and the MBH-σRelation". The Astrophysical Journal Letters 596: L27–L29. arXiv:astro-ph/0308342. Bibcode:2003ApJ...596L..27K. doi:10.1086/379143.

26.

Ferrarese, Laura; Merritt, David (2000-08-10). "A Fundamental Relationbetween Supermassive Black Holes and Their Host Galaxies". TheAstrophysical Journal (The American Astronomical Society) 539 (1): L9–12.arXiv:astro-ph/0006053. Bibcode:2000ApJ...539L...9F. doi:10.1086/312838.

27.

Bender, Ralf; et al. (2005-09-20). "HST STIS Spectroscopy of the TripleNucleus of M31: Two Nested Disks in Keplerian Rotation around aSupermassive Black Hole". The Astrophysical Journal 631 (1): 280–300.arXiv:astro-ph/0509839. Bibcode:2005ApJ...631..280B. doi:10.1086/432434.

28.

Gebhardt, Karl; Thomas, Jens (August 2009). "The Black Hole Mass, StellarMass-to-Light Ratio, and Dark Halo in M87". The Astrophysical Journal 700(2): 1690–1701. arXiv:0906.1492. Bibcode:2009ApJ...700.1690G.doi:10.1088/0004-637X/700/2/1690.

29.

Macchetto, F.; Marconi, A.; Axon, D. J.; Capetti, A.; Sparks, W.; Crane, P.(November 1997). "The Supermassive Black Hole of M87 and the Kinematicsof Its Associated Gaseous Disk". Astrophysical Journal 489 (2): 579.arXiv:astro-ph/9706252. Bibcode:1997ApJ...489..579M. doi:10.1086/304823.

30.

Overbye, Dennis (2011-12-05). "Astronomers Find Biggest Black Holes Yet".The New York Times.

31.

Major, Jason. "Watch what happens when two supermassive black holescollide". Universe today. Retrieved 4 June 2013.

32.

D. Merritt and M. Milosavljevic (2005). "Massive Black Hole BinaryEvolution." http://relativity.livingreviews.org/Articles/lrr-2005-8/

33.

Shiga, David (10 January 2008). "Biggest black hole in the cosmos discovered".NewScientist.com news service.

34.

Kaufman, Rachel (10 January 2011). "Huge Black Hole Found in DwarfGalaxy". National Geographic. Retrieved 1 June 2011.

35.

4 of 5

Wikinews has newsrelated to:

Supermassive blackholes

"Astronomers catch first glimpse of star being consumed by black hole". TheSydney Morning Herald. 2011-08-26.

36.

Burrows, D. N.; Kennea, J. A.; Ghisellini, G.; Mangano, V.; et al. (Aug 2011)."Relativistic jet activity from the tidal disruption of a star by a massive blackhole". Nature 476 (7361): 421–424. arXiv:1104.4787.Bibcode:2011Natur.476..421B. doi:10.1038/nature10374.

37.

Zauderer, B. A.; Berger, E.; Soderberg, A. M.; Loeb, A.; et al. (Aug 2011)."Birth of a relativistic outflow in the unusual γ-ray transient SwiftJ164449.3+573451". Nature 476 (7361): 425–428. arXiv:1106.3568.Bibcode:2011Natur.476..425Z. doi:10.1038/nature10366.

38.

Remco C. E. van den Bosch, Karl Gebhardt, Kayhan Gültekin, Glenn van deVen, Arjen van der Wel, Jonelle L. Walsh, An over-massive black hole in the

39.

compact lenticular galaxy NGC  1277, Nature 491, pp. 729–731 (29 November2012) doi:10.1038/nature11592 (https://dx.doi.org/10.1038%2Fnature11592),published online 28 November 2012Emsellem, Eric (2013). "Is the black hole in NGC 1277 really overmassive?".Monthly Notices of the Royal Astronomical Society 433 (3): 1862–1870.arXiv:1305.3630. Bibcode:2013MNRAS.433.1862E. doi:10.1093/mnras/stt840.Retrieved 31 August 2013.

40.

Reynolds, Christopher (2013). "Astrophysics: Black holes in a spin". Nature494: 432–433. Bibcode:2013Natur.494..432R. doi:10.1038/494432a.

41.

Prostak, Sergio (28 February 2013). "Astronomers: Supermassive Black Hole inNGC 1365 Spins at Nearly Light-Speed". Sci-News.com. Retrieved 20 March2015.

42.

Further readingFulvio Melia (2003). The Edge of Infinity. Supermassive Black Holes in the Universe. Cambridge University Press. ISBN 978-0-521-81405-8.Laura Ferrarese & David Merritt (2002). "Supermassive Black Holes". Physics World 15 (1): 41–46. arXiv:astro-ph/0206222.Bibcode:2002astro.ph..6222F.Fulvio Melia (2007). The Galactic Supermassive Black Hole. Princeton University Press. ISBN 978-0-691-13129-0.Merritt, David (2013). Dynamics and Evolution of Galactic Nuclei. Princeton University Press. ISBN 978-0-691-12101-7.Julian Krolik (1999). Active Galactic Nuclei. Princeton University Press. ISBN 0-691-01151-6.

External linksBlack Holes: Gravity's Relentless Pull (http://www.hubblesite.org/go/blackholes) Award-winning interactivemultimedia Web site about the physics and astronomy of black holes from the Space Telescope Science InstituteImages of supermassive black holes (http://chandra.harvard.edu/photo/2002/0157/0157_composite.jpg)NASA images of supermassive black holes (http://antwrp.gsfc.nasa.gov/apod/image/0210/mwcentre_eso_big.jpg)The black hole at the heart of the Milky Way (http://www.einstein-online.info/en/spotlights/milkyway_bh/index.html)ESO video clip of stars orbiting a galactic black hole (http://www.eso.org/public/videos/eso0846a/)Star Orbiting Massive Milky Way Centre Approaches to within 17 Light-Hours (http://www.eso.org/outreach/press-rel/pr-2002/pr-17-02.html) ESO,October 21, 2002Images, Animations, and New Results from the UCLA Galactic Center Group (http://www.astro.ucla.edu/research/galcenter/)Washington Post article on Supermassive black holes (http://www.washingtonpost.com/wp-dyn/content/article/2007/10/30/AR2007103002073.html?nav=most_emailed)A simulation of the stars orbiting the Milky Way's central massive black hole (http://www.youtube.com/watch?v=uVlcIb-rClI)

Retrieved from "https://en.wikipedia.org/w/index.php?title=Supermassive_black_hole&oldid=716249890"

Categories: Black holes Galaxies Supermassive black holes

This page was last modified on 20 April 2016, at 18:22.Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. By using this site, you agree to the Terms ofUse and Privacy Policy. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.

5 of 5